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Saturday, April 4, 2015

Psychiatry


From Wikipedia, the free encyclopedia

Psychiatry is the medical specialty devoted to the study, diagnosis, treatment, and prevention of mental disorders. These include various affective, behavioural, cognitive and perceptual abnormalities.

Psychiatric assessment typically starts with a mental status examination and the compilation of a case history.
Psychological tests and physical examinations may be conducted, including on occasion the use of neuroimaging or other neurophysiological techniques. Mental disorders are diagnosed in accordance with criteria listed in diagnostic manuals such as the widely used Diagnostic and Statistical Manual of Mental Disorders (DSM), published by the American Psychiatric Association, and the International Classification of Diseases (ICD), edited and used by the World Health Organization. The fifth edition of the DSM (DSM-5) was published in 2013, and its development was expected to be of significant interest to many medical fields.[1]

The combined treatment of psychiatric medication and psychotherapy has become the most common mode of psychiatric treatment in current practice,[2] but current practice also includes widely ranging variety of other modalities. Treatment may be delivered on an inpatient or outpatient basis, depending on the severity of functional impairment or on other aspects of the disorder in question. Research and treatment within psychiatry, as a whole, are conducted on an interdisciplinary basis, sourcing an array of sub-specialties and theoretical approaches.

Controversy has often surrounded psychiatry, and the term anti-psychiatry was coined by psychiatrist David Cooper in 1967. The anti-psychiatry message is that psychiatric treatments are ultimately more damaging than helpful to patients, and psychiatry's history involves what may now be seen as dangerous treatments (e.g., electroconvulsive therapy, lobotomy).[3] Some ex-patient groups have become anti-psychiatric, often referring to themselves as "survivors".[3]

Etymology


The word psyche comes from the ancient Greek for soul or butterfly.[4] The fluttering insect appears in the coat of arms of Britain's Royal College of Psychiatrists[5]

The term "psychiatry" was first coined by the German physician Johann Christian Reil in 1808 and literally means the 'medical treatment of the soul' (psych- "soul" from Ancient Greek psykhē "soul"; -iatry "medical treatment" from Gk. iātrikos "medical" from iāsthai "to heal"). A medical doctor specializing in psychiatry is a psychiatrist. (For a historical overview, see Timeline of psychiatry.)

Theory and focus

"Psychiatry, more than any other branch of medicine, forces its practitioners to wrestle with the nature of evidence, the validity of introspection, problems in communication, and other long-standing philosophical issues" (Guze, 1992, p.4).
Psychiatry refers to a field of medicine focused specifically on the mind, aiming to study, prevent, and treat mental disorders in humans.[6][7][8] It has been described as an intermediary between the world from a social context and the world from the perspective of those who are mentally ill.[9]

People who specialize in psychiatry often differ from most other mental health professionals and physicians in that they must be familiar with both the social and biological sciences.[7] The discipline studies the operations of different organs and body systems as classified by the patient's subjective experiences and the objective physiology of the patient.[10] Psychiatry treats mental disorders, which are conventionally divided into three very general categories: mental illnesses, severe learning disabilities, and personality disorders.[11] While the focus of psychiatry has changed little over time, the diagnostic and treatment processes have evolved dramatically and continue to do so. Since the late 20th century the field of psychiatry has continued to become more biological and less conceptually isolated from other medical fields.[12]

Scope of practice


Disability-adjusted life year for neuropsychiatric conditions per 100,000 inhabitants in 2002.
  no data
  less than 10
  10-20
  20-30
  30-40
  40-50
  50-60
  60-80
  80-100
  100-120
  120-140
  140-150
  more than 150

Though the medical specialty of psychiatry utilizes research in the field of neuroscience, psychology, medicine, biology, biochemistry, and pharmacology,[13] it has generally been considered a middle ground between neurology and psychology.[14] Unlike other physicians and neurologists, psychiatrists specialize in the doctor–patient relationship and are trained to varying extents in the use of psychotherapy and other therapeutic communication techniques.[14] Psychiatrists also differ from psychologists in that they are physicians and only their residency training (usually 3 to 4 years) is in psychiatry; their undergraduate medical training is identical to all other physicians.[15] Psychiatrists can therefore counsel patients, prescribe medication, order laboratory tests, order neuroimaging, and conduct physical examinations.[16]

Ethics

Like other purveyors of professional ethics, the World Psychiatric Association issues an ethical code to govern the conduct of psychiatrists. The psychiatric code of ethics, first set forth through the Declaration of Hawaii in 1977, has been expanded through a 1983 Vienna update and, in 1996, the broader Madrid Declaration. The code was further revised during the organization's general assembblies in 1999, 2002, 2005, and 2011.[17] The World Psychiatric Association code covers such matters as patient assessment, up-to-date knowledge, the human dignity of incapacitated patients, confidentiality, research ethics, sex selection, euthanasia,[18] organ transplantation, torture,[19][20] the death penalty, media relations, genetics, and ethnic or cultural discrimination.[17]
In establishing such ethical codes, the profession has responded to a number of controversies about the practice of psychiatry, for example, surrounding the use of lobotomy and electroconvulsive therapy. Discredited psychiatrists who operated outside the norms of medical ethics include Harry Bailey, Donald Ewen Cameron, Samuel A. Cartwright, Henry Cotton, and Andrei Snezhnevsky.[21][page needed]

Approaches

Psychiatric illnesses can be conceptualised in a number of different ways. The biomedical approach examines signs and symptoms and compares them with diagnostic criteria. Mental illness can be assessed, conversely, through a narrative which tries to incorporate symptoms into a meaningful life history and to frame them as responses to external conditions. Both approaches are important in the field of psychiatry,[22] but have not sufficiently reconciled to settle controversy over either the selection of a psychiatric paradigm or the specification of psychopathology. The notion of a "biopsychosocial model" is often used to underline the multifactorial nature of clinical impairment.[23][24][25] In this notion the word "model" is not used in a strictly scientific way though.[23] Alternatively, a "biocognitive model" acknowledges the physiological basis for the mind's existence, but identifies cognition as an irreducible and independent realm in which disorder may occur.[23][24][25] The biocognitive approach includes a mentalist etiology and provides a natural dualist (i.e. non-spiritual) revision of the biopsychosocial view, reflecting the efforts of Australian psychiatrist Niall McLaren to bring the discipline into scientific maturity in accordance with the paradigmatic standards of philosopher Thomas Kuhn.[23][24][25]

Subspecialties

Various subspecialties and/or theoretical approaches exist which are related to the field of psychiatry. They include the following:
  • Addiction psychiatry; focuses on evaluation and treatment of individuals with alcohol, drug, or other substance-related disorders, and of individuals with dual diagnosis of substance-related and other psychiatric disorders.
  • Biological psychiatry; an approach to psychiatry that aims to understand mental disorders in terms of the biological function of the nervous system.
  • Child and adolescent psychiatry; the branch of psychiatry that specializes in work with children, teenagers, and their families.
  • Community psychiatry; an approach that reflects an inclusive public health perspective and is practiced in community mental health services.[26]
  • Cross-cultural psychiatry; a branch of psychiatry concerned with the cultural and ethnic context of mental disorder and psychiatric services.
  • Emergency psychiatry; the clinical application of psychiatry in emergency settings.
  • Forensic psychiatry; the interface between law and psychiatry.
  • Geriatric psychiatry; a branch of psychiatry dealing with the study, prevention, and treatment of mental disorders in humans with old age.
  • Liaison psychiatry; the branch of psychiatry that specializes in the interface between other medical specialties and psychiatry.
  • Military psychiatry; covers special aspects of psychiatry and mental disorders within the military context.
  • Neuropsychiatry; branch of medicine dealing with mental disorders attributable to diseases of the nervous system.
  • Social psychiatry; a branch of psychiatry that focuses on the interpersonal and cultural context of mental disorder and mental well-being.
In larger healthcare organizations, both public and private, psychiatrists often serve in senior management roles, where they are responsible for the efficient and effective delivery of mental health services for the organization's constituents. For example, the Chief of Mental Health Services at most VA medical centers is usually a psychiatrist, although psychologists occasionally are selected for the position as well.[citation needed]

In the United States, psychiatry is one of the specialties which qualify for further education and board-certification in pain medicine, palliative medicine, and sleep medicine.

Industry and academia

Practitioners

All physicians can diagnose mental disorders and prescribe treatments utilizing principles of psychiatry. Psychiatrists are either: 1) clinicians who specialize in psychiatry and are certified in treating mental illness;[27] or (2) scientists in the academic field of psychiatry who are qualified as research doctors in this field. Psychiatrists may also go through significant training to conduct psychotherapy, psychoanalysis and cognitive behavioral therapy, but it is their training as physicians that differentiates them from other mental health professionals.[27]

Research

Psychiatric research is, by its very nature, interdisciplinary; combining social, biological and psychological perspectives in attempt to understand the nature and treatment of mental disorders.[28] Clinical and research psychiatrists study basic and clinical psychiatric topics at research institutions and publish articles in journals.[13][29][30][31] Under the supervision of institutional review boards, psychiatric clinical researchers look at topics such as neuroimaging, genetics, and psychopharmacology in order to enhance diagnostic validity and reliability, to discover new treatment methods, and to classify new mental disorders.[32]

Clinical application

Diagnostic systems

See also Diagnostic classification and rating scales used in psychiatry

MRI or CT images may assist in a diagnosis by ruling out other conditions.

Psychiatric diagnoses take place in a wide variety of settings and are performed by many different health professionals. Therefore, the diagnostic procedure may vary greatly based upon these factors. Typically, though, a psychiatric diagnosis utilizes a differential diagnosis procedure where a mental status examination and physical examination is conducted, with pathological, psychopathological or psychosocial histories obtained, and sometimes neuroimages or other neurophysiological measurements are taken, or personality tests or cognitive tests administered.[33][34][35][36][37] In some cases, a brain scan might be used to rule out other medical illnesses, but at this time relying on brain scans alone cannot accurately diagnose a mental illness or tell the risk of getting a mental illness in the future.[38] A few psychiatrists are beginning to utilize genetics during the diagnostic process but on the whole this remains a research topic.[39][40][41]

Diagnostic manuals

Three main diagnostic manuals used to classify mental health conditions are in use today. The ICD-10 is produced and published by the World Health Organization, includes a section on psychiatric conditions, and is used worldwide.[42] The Diagnostic and Statistical Manual of Mental Disorders, produced and published by the American Psychiatric Association, is primarily focused on mental health conditions and is the main classification tool in the United States.[43] It is currently in its fourth revised edition and is also used worldwide.[43] The Chinese Society of Psychiatry has also produced a diagnostic manual, the Chinese Classification of Mental Disorders.[44]The stated intention of diagnostic manuals is typically to develop replicable and clinically useful categories and criteria, to facilitate consensus and agreed upon standards, whilst being atheoretical as regards etiology.[43][45]
However, the categories are nevertheless based on particular psychiatric theories and data; they are broad and often specified by numerous possible combinations of symptoms, and many of the categories overlap in symptomology or typically occur together.[46] While originally intended only as a guide for experienced clinicians trained in its use, the nomenclature is now widely used by clinicians, administrators and insurance companies in many countries.[47]

The DSM has attracted praise for standardizing psychiatric diagnostic categories and criteria. It has also attracted controversy and criticism. Some critics argue that the DSM represents an unscientific system that enshrines the opinions of a few powerful psychiatrists. There are ongoing issues concerning the validity and reliability of the diagnostic categories; the reliance on superficial symptoms; the use of artificial dividing lines between categories and from 'normality'; possible cultural bias; medicalization of human distress and financial conflicts of interest, including with the practice of psychiatrists and with the pharmaceutical industry; political controversies about the inclusion or exclusion of diagnoses from the manual, in general or in regard to specific issues; and the experience of those who are most directly affected by the manual by being diagnosed, including the consumer/survivor movement.[48][49][50][51] The publication of the DSM, with tightly guarded copyrights, now makes APA over $5 million a year, historically adding up to over $100 million.[52]

Treatment

General considerations


NIMH federal agency patient room for Psychiatric research, Maryland, USA.

Individuals with mental health conditions are commonly referred to as patients but may also be called clients, consumers, or service recipients. They may come under the care of a psychiatric physician or other psychiatric practitioners by various paths, the two most common being self-referral or referral by a primary-care physician. Alternatively, a person may be referred by hospital medical staff, by court order, involuntary commitment, or, in the UK and Australia, by sectioning under a mental health law.

Persons who undergo a psychiatric assessment are evaluated by a psychiatrist for their mental and physical condition. This usually involves interviewing the person and often obtaining information from other sources such as other health and social care professionals, relatives, associates, law enforcement personnel, emergency medical personnel, and psychiatric rating scales. A mental status examination is carried out, and a physical examination is usually performed to establish or exclude other illnesses that may be contributing to the alleged psychiatric problems. A physical examination may also serve to identify any signs of self-harm; this examination is often performed by someone other than the psychiatrist, especially if blood tests and medical imaging are performed.

Like most medications, psychiatric medications can cause adverse effects in patients, and some require ongoing therapeutic drug monitoring, for instance full blood counts serum drug levels, renal function, liver function, and/or thyroid function. Electroconvulsive therapy (ECT) is sometimes administered for serious and disabling conditions, such as those unresponsive to medication. The efficacy[53][54] and adverse effects of psychiatric drugs may vary from patient to patient.

For many years, controversy has surrounded the use of involuntary treatment and use of the term "lack of insight" in describing patients. Mental health laws vary significantly among jurisdictions, but in many cases, involuntary psychiatric treatment is permitted when there is deemed to be a risk to the patient or others due to the patient's illness. Involuntary treatment refers to treatment that occurs based on the treating physician's recommendations without requiring consent from the patient.[55]

Inpatient treatment

Psychiatric treatments have changed over the past several decades. In the past, psychiatric patients were often hospitalized for six months or more, with some cases involving hospitalization for many years. Today, people receiving psychiatric treatment are more likely to be seen as outpatients. If hospitalization is required, the average hospital stay is around one to two weeks, with only a small number receiving long-term hospitalization.[citation needed]

Psychiatric inpatients are people admitted to a hospital or clinic to receive psychiatric care. Some are admitted involuntarily, perhaps committed to a secure hospital, or in some jurisdictions to a facility within the prison system. In many countries including the USA and Canada, the criteria for involuntary admission vary with local jurisdiction. They may be as broad as having a mental health condition, or as narrow as being an immediate danger to themselves and/or others. Bed availability is often the real determinant of admission decisions to hard pressed public facilities. European Human Rights legislation restricts detention to medically certified cases of mental disorder, and adds a right to timely judicial review of detention.[citation needed]

Injections are one of many ways to administer psychiatric medication.

Patients may be admitted voluntarily if the treating doctor considers that safety isn't compromised by this less restrictive option. Inpatient psychiatric wards may be secure (for those thought to have a particular risk of violence or self-harm) or unlocked/open. Some wards are mixed-sex whilst same-sex wards are increasingly favored to protect women inpatients. Once in the care of a hospital, people are assessed, monitored, and often given medication and care from a multidisciplinary team, which may include physicians, pharmacists, psychiatric nurse practitioners, psychiatric nurses, clinical psychologists, psychotherapists, psychiatric social workers, occupational therapists and social workers. If a person receiving treatment in a psychiatric hospital is assessed as at particular risk of harming themselves or others, they may be put on constant or intermittent one-to-one supervision, and may be physically restrained or medicated. People on inpatient wards may be allowed leave for periods of time, either accompanied or on their own.[56]

In many developed countries there has been a massive reduction in psychiatric beds since the mid 20th century, with the growth of community care. Standards of inpatient care remain a challenge in some public and private facilities, due to levels of funding, and facilities in developing countries are typically grossly inadequate for the same reason. Even in developed countries, programs in public hospitals vary widely. Some may offer structured activities and therapies offered from many perspectives while others may only have the funding for medicating and monitoring patients. This may be problematic in that the maximum amount of therapeutic work might not actually take place in the hospital setting. This is why hospitals are increasingly used in limited situations and moments of crises where patients are a direct threat to themselves or others. Alternatives to psychiatric hospitals that may actively offer more therapeutic approaches include rehabilitation centers or "rehab" as popularly termed.[citation needed]

Outpatient treatment

Outpatient treatment involves periodic visits to a psychiatrist for consultation in his or her office, or at a community-based outpatient clinic. Initial appointments, at which the psychiatrist conducts a psychiatric assessment or evaluation of the patient, are typically 45 to 75 minutes in length. Follow-up appointments are generally shorter in duration, i.e., 15 to 30 minutes, with a focus on making medication adjustments, reviewing potential medication interactions, considering the impact of other medical disorders on the patient's mental and emotional functioning, and counseling patients regarding changes they might make to facilitate healing and remission of symptoms (e.g., exercise, cognitive therapy techniques, sleep hygiene—to name just a few). The frequency with which a psychiatrist sees people in treatment varies widely, from once a week to twice a year, depending on the type, severity and stability of each person's condition, and depending on what the clinician and patient decide would be best.

Increasingly, psychiatrists are limiting their practices to psychopharmacology (prescribing medications), as opposed to previous practice in which a psychiatrist would provide traditional 50-minute psychotherapy sessions, of which psychopharmacology would be a part, but most of the consultation sessions consisted of "talk therapy." This shift began in the early 1980s and accelerated in the 1990s and 2000s.[57] A major reason for this change was the advent of managed care insurance plans, which began to limit reimbursement for psychotherapy sessions provided by psychiatrists. The underlying assumption was that psychopharmacology was at least as effective as psychotherapy, and it could be delivered more efficiently because less time is required for the appointment.[58][59][60][61][62][63] For example, most psychiatrists schedule three or four follow-up appointments per hour, as opposed to seeing one patient per hour in the traditional psychotherapy model.[a]

Because of this shift in practice patterns, psychiatrists often refer patients whom they think would benefit from psychotherapy to other mental health professionals, e.g., clinical social workers and psychologists.[69]

History

Ancient

Specialty in psychiatry can be traced in Ancient India. The oldest texts on psychiatry include the ayurvedic text, Charaka Samhita.[70][71] Some of the first hospitals for curing mental illness were established during 3rd century BCE.[72]

During the 5th century BCE, mental disorders, especially those with psychotic traits, were considered supernatural in origin,[73] a view which existed throughout ancient Greece and Rome.[73] The beginning of psychiatry as a medical specialty is dated to the middle of the nineteenth century,[74] although one may trace its germination to the late eighteenth century.

Some of the early manuals about mental disorders were created by the Greeks.[74] In the 4th century BCE, Hippocrates theorized that physiological abnormalities may be the root of mental disorders.[73] In 4th to 5th Century B.C. Greece, Hippocrates wrote that he visited Democritus and found him in his garden cutting open animals. Democritus explained that he was attempting to discover the cause of madness and melancholy. Hippocrates praised his work. Democritus had with him a book on madness and melancholy.[75]

Religious leaders often turned to versions of exorcism to treat mental disorders often utilizing methods that many consider to be cruel and/or barbaric methods.[73]

Middle Ages

Specialist hospitals were built in Baghdad in 705 AD,[76] followed by Fes in the early 8th century, and Cairo in 800 AD.[citation needed]
Physicians who wrote on mental disorders and their treatment in the Medieval Islamic period included Muhammad ibn Zakariya al-Razi (Rhazes), the Arab physician Najab ud-din Muhammad[citation needed], and Abu Ali al-Hussain ibn Abdallah ibn Sina, known in the West as Avicenna.[77][78][79]

Specialist hospitals were built in medieval Europe from the 13th century to treat mental disorders but were utilized only as custodial institutions and did not provide any type of treatment.[80]

Early modern period

A map of the original Bethlem Hospital site
Plan of the Bethlem Royal Hospital, an early public asylum for the mentally ill.

Founded in the 13th century, Bethlem Royal Hospital in London was one of the oldest lunatic asylums.[80] In the late 17th century, privately run asylums for the insane began to proliferate and expand in size. Already in 1632 it was recorded that Bethlem Royal Hospital, London had "below stairs a parlor, a kitchen, two larders, a long entry throughout the house, and 21 rooms wherein the poor distracted people lie, and above the stairs eight rooms more for servants and the poor to lie in".[81] Inmates who were deemed dangerous or disturbing were chained, but Bethlem was an otherwise open building for its inhabitants to roam around its confines and possibly throughout the general neighborhood in which the hospital was situated.[82] In 1676, Bethlem expanded into newly built premises at Moorfields with a capacity for 100 inmates.[83]:155[84]:27

In 1713 the Bethel Hospital Norwich was opened, the first purpose-built asylum in England, founded by Mary Chapman.[85]

In 1621, Oxford University mathematician, astrologer, and scholar Robert Burton published one of the earliest treatises on mental illness, The Anatomy of Melancholy, What it is: With all the Kinds, Causes, Symptomes, Prognostickes, and Several Cures of it. In Three Maine Partitions with their several Sections, Members, and Subsections. Philosophically, Medicinally, Historically, Opened and Cut Up. Burton thought that there was "no greater cause of melancholy than idleness, no better cure than business." Unlike English philosopher of science Francis Bacon, Burton argued that knowledge of the mind, not natural science, is humankind's greatest need.[86]

In 1656, Louis XIV of France created a public system of hospitals for those suffering from mental disorders, but as in England, no real treatment was applied.[87]

Humanitarian reform

Dr. Philippe Pinel at the Salpêtrière, 1795 by Tony Robert-Fleury. Pinel ordering the removal of chains from patients at the Paris Asylum for insane women.

During the Enlightenment attitudes towards the mentally ill began to change. It came to be viewed as a disorder that required compassionate treatment that would aid in the rehabilitation of the victim. In 1758 English physician William Battie wrote his Treatise on Madness on the management of mental disorder. It was a critique aimed particularly at the Bethlem Hospital, where a conservative regime continued to use barbaric custodial treatment. Battie argued for a tailored management of patients entailing cleanliness, good food, fresh air, and distraction from friends and family. He argued that mental disorder originated from dysfunction of the material brain and body rather than the internal workings of the mind.[88][89]

Thirty years later, then ruling monarch in England George III was known to be suffering from a mental disorder.[73] Following the King's remission in 1789, mental illness came to be seen as something which could be treated and cured.[73] The introduction of moral treatment was initiated independently by the French doctor Philippe Pinel and the English Quaker William Tuke.[73]

In 1792 Pinel became the chief physician at the Bicêtre Hospital. In 1797, Pussin first freed patients of their chains and banned physical punishment, although straitjackets could be used instead.[90][91]

Patients were allowed to move freely about the hospital grounds, and eventually dark dungeons were replaced with sunny, well-ventilated rooms. Pussin and Pinel's approach was seen as remarkably successful and they later brought similar reforms to a mental hospital in Paris for female patients, La Salpetrière. Pinel's student and successor, Jean Esquirol (1772–1840), went on to help establish 10 new mental hospitals that operated on the same principles.
There was an emphasis on the selection and supervision of attendants in order to establish a suitable setting to facilitate psychological work, and particularly on the employment of ex-patients as they were thought most likely to refrain from inhumane treatment while being able to stand up to pleading, menaces, or complaining.[92]

The York Retreat (c.1796) was built by William Tuke, a pioneer of moral treatment for the insane.

William Tuke led the development of a radical new type of institution in northern England, following the death of a fellow Quaker in a local asylum in 1790.[93]:84–85 [94]:30 [95] In 1796, with the help of fellow Quakers and others, he founded the York Retreat, where eventually about 30 patients lived as part of a small community in a quiet country house and engaged in a combination of rest, talk, and manual work. Rejecting medical theories and techniques, the efforts of the York Retreat centered around minimizing restraints and cultivating rationality and moral strength. The entire Tuke family became known as founders of moral treatment.[96]

William Tuke's grandson, Samuel Tuke, published an influential work in the early 19th century on the methods of the retreat; Pinel's Treatise On Insanity had by then been published, and Samuel Tuke translated his term as "moral treatment". Tuke's Retreat became a model throughout the world for humane and moral treatment of patients suffering from mental disorders.[96] The York Retreat inspired similar institutions in the United States, most notably the Brattleboro Retreat and the Hartford Retreat (now The Institute of Living).

Although Tuke, Pinel and others had tried to do away with physical restraint, it remained widespread into the 19th century. At the Lincoln Asylum in England, Robert Gardiner Hill, with the support of Edward Parker Charlesworth, pioneered a mode of treatment that suited "all types" of patients, so that mechanical restraints and coercion could be dispensed with — a situation he finally achieved in 1838. In 1839 Sergeant John Adams and Dr. John Conolly were impressed by the work of Hill, and introduced the method into their Hanwell Asylum, by then the largest in the country. Hill's system was adapted, since Conolly was unable to supervise each attendant as closely as Hill had done. By September 1839, mechanical restraint was no longer required for any patient.[97][98]

Phrenology

Main article: Phrenology

William A. F. Browne was an influential reformer of the lunatic asylum in the mid-19th century, and an advocate of the new 'science' of phrenology.

Scotland's Edinburgh medical school of the eighteenth century developed an interest in mental illness, with influential teachers including William Cullen (1710–1790) and Robert Whytt (1714–1766) emphasising the clinical importance of psychiatric disorders. In 1816, the phrenologist Johann Spurzheim (1776–1832) visited Edinburgh and lectured on his craniological and phrenological concepts; the central concepts of the system were that the brain is the organ of the mind and that human behaviour can be usefully understood in neurological rather than philosophical or religious terms. Phrenologists also laid stress on the modularity of mind.

Some of the medical students, including William A. F. Browne (1805–1885), responded very positively to this materialist conception of the nervous system and, by implication, of mental disorder. George Combe (1788–1858), an Edinburgh solicitor, became an unrivalled exponent of phrenological thinking, and his brother, Andrew Combe (1797–1847), who was later appointed a physician to Queen Victoria, wrote a phrenological treatise entitled Observations on Mental Derangement (1831). They also founded the Edinburgh Phrenological Society in 1820.

Institutionalization

The modern era of institutionalized provision for the care of the mentally ill, began in the early 19th century with a large state-led effort. Public mental asylums were established in Britain after the passing of the 1808 County Asylums Act. This empowered magistrates to build rate-supported asylums in every county to house the many 'pauper lunatics'. Nine counties first applied, and the first public asylum opened in 1812 in Nottinghamshire. Parliamentary Committees were established to investigate abuses at private madhouses like Bethlem Hospital - its officers were eventually dismissed and national attention was focused on the routine use of bars, chains and handcuffs and the filthy conditions the inmates lived in. However, it was not until 1828 that the newly appointed Commissioners in Lunacy were empowered to license and supervise private asylums.

Lord Shaftesbury, a vigorous campaigner for the reform of lunacy law in England, and the Head of the Lunacy Commission for 40 years.

The Lunacy Act 1845 was an important landmark in the treatment of the mentally ill, as it explicitly changed the status of mentally ill people to patients who required treatment. The Act created the Lunacy Commission, headed by Lord Shaftesbury, to focus on lunacy legislation reform.[99] The Commission was made up of eleven Metropolitan Commissioners who were required to carry out the provisions of the Act;[100][full citation needed] the compulsory construction of asylums in every county, with regular inspections on behalf of the Home Secretary. All asylums were required to have written regulations and to have a resident qualified physician.[100] A national body for asylum superintendents - the Medico-Psychological Association - was established in 1866 under the Presidency of William A. F. Browne, although the body appeared in an earlier form in 1841.[101]

In 1838, France enacted a law to regulate both the admissions into asylums and asylum services across the country. Édouard Séguin developed a systematic approach for training individuals with mental deficiencies,[102] and, in 1839, he opened the first school for the severely retarded. His method of treatment was based on the assumption that the mentally deficient did not suffer from disease.[103]

In the United States, the erection of state asylums began with the first law for the creation of one in New York, passed in 1842. The Utica State Hospital was opened approximately in 1850. The creation of this hospital, as of many others, was largely the work of Dorothea Lynde Dix, whose philanthropic efforts extended over many states, and in Europe as far as Constantinople. Many state hospitals in the United States were built in the 1850s and 1860s on the Kirkbride Plan, an architectural style meant to have curative effect.[104]

At the turn of the century, England and France combined had only a few hundred individuals in asylums.[105] By the late 1890s and early 1900s, this number had risen to the hundreds of thousands. However, the idea that mental illness could be ameliorated through institutionalization was soon disappointed.[106] Psychiatrists were pressured by an ever increasing patient population.[106] The average number of patients in asylums kept on growing.[106] Asylums were quickly becoming almost indistinguishable from custodial institutions,[107] and the reputation of psychiatry in the medical world had hit an extreme low.[108]

Scientific advances


Emil Kraepelin studied and promoted ideas of disease classification for mental disorders.

In the early 1800s, psychiatry made advances in the diagnosis of mental illness by broadening the category of mental disease to include mood disorders, in addition to disease level delusion or irrationality.[109] The term psychiatry (Greek "ψυχιατρική", psychiatrikē) which comes from the Greek "ψυχή" (psychē: "soul or mind") and "ιατρός" (iatros: "healer") was coined by Johann Christian Reil in 1808.[110][unreliable source?][111] Jean-Étienne Dominique Esquirol, a student of Pinel, defined lypemania as an 'affective monomania' (excessive attention to a single thing). This was an early diagnosis of depression.[109][112]

The 20th century introduced a new psychiatry into the world. Different perspectives of looking at mental disorders began to be introduced. The career of Emil Kraepelin reflects the convergence of different disciplines in psychiatry.[113] Kraepelin initially was very attracted to psychology and ignored the ideas of anatomical psychiatry.[113] Following his appointment to a professorship of psychiatry and his work in a university psychiatric clinic, Kraepelin's interest in pure psychology began to fade and he introduced a plan for a more comprehensive psychiatry.[114] Kraepelin began to study and promote the ideas of disease classification for mental disorders, an idea introduced by Karl Ludwig Kahlbaum.[115] The initial ideas behind biological psychiatry, stating that the different mental disorders were all biological in nature, evolved into a new concept of "nerves" and psychiatry became a rough approximation of neurology and neuropsychiatry.[116] However, Kraepelin was criticized for considering schizophrenia as a biological illness in the absence of any detectable histologic or anatomic abnormalities.[117]:221 While Kraepelin tried to find organic causes of mental illness, he adopted many theses of positivist medicine, but he favoured the precision of nosological classification over the indefiniteness of etiological causation as his basic mode of psychiatric explanation.[118]

Following Sigmund Freud's pioneering work, ideas stemming from psychoanalytic theory also began to take root in psychiatry.[119] The psychoanalytic theory became popular among psychiatrists because it allowed the patients to be treated in private practices instead of warehoused in asylums.[119] By the 1970s the psychoanalytic school of thought had become marginalized within the field.[119]

Otto Loewi's work led to the identification of the first neurotransmitter, acetylcholine.

Biological psychiatry reemerged during this time. Psychopharmacology became an integral part of psychiatry starting with Otto Loewi's discovery of the neuromodulatory properties of acetylcholine; thus identifying it as the first-known neurotransmitter.[120] Neuroimaging was first utilized as a tool for psychiatry in the 1980s.[121] The discovery of chlorpromazine's effectiveness in treating schizophrenia in 1952 revolutionized treatment of the disorder,[122] as did lithium carbonate's ability to stabilize mood highs and lows in bipolar disorder in 1948.[123] Psychotherapy was still utilized, but as a treatment for psychosocial issues.[124] In the 1920s and 1930s, most asylum and academic psychiatrists in Europe believed that manic depressive disorder and schizophrenia were inherited, but in the decades after World War II, the conflation of genetics with Nazi racist ideology thoroughly discredited genetics.[125]

Now genetics are once again thought by some to play a role in mental illness.[120][126][unreliable medical source?] Geneticist Müller-Hill is quoted as saying "Genes are not destiny, they may give an individual a pre-disposition toward a disorder, for example, but that only means they are more likely than others to have it. It (mental illness) is not a certainty.”[127][unreliable medical source?] Molecular biology opened the door for specific genes contributing to mental disorders to be identified.[120]

Deinstitutionalization

Asylums: Essays on the Social Situation of Mental Patients and Other Inmates (1961), written by sociologist Erving Goffman,[128][129][better source needed] examined the social situation of mental patients in the hospital.[130] Based on his participant observation field work, the book developed the theory of the "total institution" and the process by which it takes efforts to maintain predictable and regular behavior on the part of both "guard" and "captor". The book suggested that many of the features of such institutions serve the ritual function of ensuring that both classes of people know their function and social role, in other words of "institutionalizing" them. Asylums was a key text in the development of deinstitutionalisation.[131]
In 1963, US president John F. Kennedy introduced legislation delegating the National Institute of Mental Health to administer Community Mental Health Centers for those being discharged from state psychiatric hospitals.[132] Later, though, the Community Mental Health Centers focus shifted to providing psychotherapy for those suffering from acute but less serious mental disorders.[132] Ultimately there were no arrangements made for actively following and treating severely mentally ill patients who were being discharged from hospitals.[132] Some of those suffering from mental disorders drifted into homelessness or ended up in prisons and jails.[132][133] Studies found that 33% of the homeless population and 14% of inmates in prisons and jails were already diagnosed with a mental illness.[132][134]

In 1973, psychologist David Rosenhan published the Rosenhan experiment, a study with results that led to questions about the validity of psychiatric diagnoses.[135] Critics such as Robert Spitzer placed doubt on the validity and credibility of the study, but did concede that the consistency of psychiatric diagnoses needed improvement.[136]
Psychiatry, like most medical specialties has a continuing, significant need for research into its diseases, classifications and treatments.[137] Psychiatry adopts biology's fundamental belief that disease and health are different elements of an individual's adaptation to an environment.[138] But psychiatry also recognizes that the environment of the human species is complex and includes physical, cultural, and interpersonal elements.[138] In addition to external factors, the human brain must contain and organize an individual's hopes, fears, desires, fantasies and feelings.[138] Psychiatry's difficult task is to bridge the understanding of these factors so that they can be studied both clinically and physiologically.[138]

Controversy

Power imbalance

Too often it is felt institutions have too much power, concerns of patients or their relatives are ignored.[139]
Psychiatric nurses impose decisions, are reluctant to share information and feel they know best. Only a minority of staff involve patients in decision making.[140] Client empowerment can improve power imbalance. Psychiatrically ill patients are at risk of abuse and discrimination in the mental health system and also the primary care sector. Studies are needed to determine whether power imbalance leads to abuse.[141] Some degree of power imbalance appears inevitable since some patients lack decision making capacity but even then patients benefit from being impowered within their limits. For example a patient felt lethargic in mornings due to medication she was required to take. She was allowed to stay in bed and miss breakfast as she wanted.[142][better source needed] Multidisciplinary teams benefit patients to the extent that professionals with a range of different expertise are caring for them. There is also a problem because patients who complain about the way they are treated face a group rather than one individual opposing them.[143]

Mental illness myth


Vienna's NarrenturmGerman for "fools' tower" — was one of the earliest buildings specifically designed as a "madhouse". It was built in 1784.

Since the 1960s there have been many challenges to the concept of mental illness itself. Thomas Szasz wrote The Myth of Mental Illness (1960) which said that mental illnesses are not real in the sense that cancers are real. Except for a few identifiable brain diseases, such as Alzheimer’s disease, there are "neither biological or chemical tests nor biopsy or necropsy findings" for verifying or falsifying psychiatric diagnoses. There are no objective methods for detecting the presence or absence of mental disease. Szasz argued that mental illness was a myth used to disguise moral conflicts. He has said "serious persons ought not to take psychiatry seriously -- except as a threat to reason, responsibility and liberty".[144]

Sociologists such as Erving Goffman and Thomas Scheff said that mental illness was merely another example of how society labels and controls non-conformists; behavioural psychologists challenged psychiatry's fundamental reliance on unobservable phenomena; and gay rights activists criticised the APA's listing of homosexuality as a mental disorder. A widely publicised study by Rosenhan in Science was viewed as an attack on the efficacy of psychiatric diagnosis.[145]

These critiques targeted the heart of psychiatry:
They suggested that psychiatry's core concepts were myths, that psychiatry's relationship to medical science had only historical connections, that psychiatry was more aptly characterised as a vast system of coercive social management, and that its paradigmatic practice methods (the talking cure and psychiatric confinement) were ineffective or worse.[21]:136

Medicalization of normality

For many years, some psychiatrists (such as Peter Breggin, Paula Caplan, Thomas Szasz) and outside critics (such as Stuart A. Kirk) have "been accusing psychiatry of engaging in the systematic medicalization of normality". More recently these concerns have come from insiders who have worked for and promoted the APA (e.g., Robert Spitzer, Allen Frances).[21]:185 In 2013, Allen Frances said that "psychiatric diagnosis still relies exclusively on fallible subjective judgments rather than objective biological tests".[146][147]

Medicalization of deviance

The concept of medicalization is created by sociologists and used for explaining how medical knowledge is applied to a series of behaviors, over which medicine exerts control, although those behaviors are not self-evidently medical or biological.[148] According to Kittrie, a number of phenomena considered "deviant", such as alcoholism, drug addiction and mental illness, were originally considered as moral, then legal, and now medical problems.[149]:1[150] As a result of these perceptions, peculiar deviants were subjected to moral, then legal, and now medical modes of social control.[149]:1 Similarly, Conrad and Schneider concluded their review of the medicalization of deviance by supposing that three major paradigms may be identified that have reigned over deviance designations in different historical periods: deviance as sin; deviance as crime; and deviance as sickness.[149]:1[151]:36 According to Franco Basaglia and his followers, whose approach pointed out the role of psychiatric institutions in the control and medicalization of deviant behaviors and social problems, psychiatry is used as the provider of scientific support for social control to the existing establishment, and the ensuing standards of deviance and normality brought about repressive views of discrete social groups.[152]:70 As scholars have long argued, governmental and medical institutions code menaces to authority as mental diseases during political disturbances.[153]

Political abuse

Psychiatrists have been involved in human rights abuses in states across the world when the definitions of mental disease were expanded to include political disobedience.[154] As scholars have long argued, governmental and medical institutions code menaces to authority as mental diseases during political disturbances.[153] Nowadays, in many countries, political prisoners are sometimes confined and abused in mental institutions.[155]:3 Psychiatric confinement of sane people is a particularly pernicious form of repression.[156]
Psychiatry possesses a built-in capacity for abuse that is greater than in other areas of medicine.[157] The diagnosis of mental disease allows the state to hold persons against their will and insist upon therapy in their interest and in the broader interests of society.[157] In addition, receiving a psychiatric diagnosis can in itself be regarded as oppressive.[158]:94 In a monolithic state, psychiatry can be used to bypass standard legal procedures for establishing guilt or innocence and allow political incarceration without the ordinary odium attaching to such political trials.[157] The use of hospitals instead of jails prevents the victims from receiving legal aid before the courts, makes indefinite incarceration possible, discredits the individuals and their ideas.[159]:29 In that manner, whenever open trials are undesirable, they are avoided.[159]:29

Examples of political abuse of the power, entrusted in physicians and particularly psychiatrists, are abundant in history and seen during the Nazi era and the Soviet rule when political dissenters were labeled as “mentally ill” and subjected to inhumane “treatments.”[160] In the period from the 1960s up to 1986, abuse of psychiatry for political purposes was reported to be systematic in the Soviet Union, and occasional in other Eastern European countries such as Romania, Hungary, Czechoslovakia, and Yugoslavia.[157] The practice of incarceration of political dissidents in mental hospitals in Eastern Europe and the former USSR damaged the credibility of psychiatric practice in these states and entailed strong condemnation from the international community.[161] Political abuse of psychiatry also takes place in the People's Republic of China[162] and in Russia.[163] Psychiatric diagnoses such as the diagnosis of ‘sluggish schizophrenia’ in political dissidents in the USSR were used for political purposes.[164]:77

Electroconvulsive therapy

Electroconvulsive therapy (ECT) was one treatment that the anti-psychiatry movement wanted eliminated.[165] Their arguments were that ECT damages the brain,[165] and was used as punishment or as a threat to keep the patients "in line".[165] Since then, ECT has improved considerably,[166] and is performed under general anaesthetic in a medically supervised environment.[167]

The National Institute for Health and Care Excellence recommends ECT for the short term treatment of severe, treatment-resistant depression, and advises against its use in schizophrenia.[168][169] According to the Canadian Network for Mood and Anxiety Treatments, ECT is more efficacious for the treatment of depression than antidepressants, with a response rate of 90% in first line treatment and 50-60% in treatment-resistant patients.[170] On the other hand, a 2010 literature review concluded that ECT had minimal benefits for people with depression and schizophrenia.[171]

The most common side effects include headache, muscle soreness, confusion, and temporary loss of recent memory.[167][172] There is no credible evidence supporting claims that ECT causes structural damage to the brain.[170]

Deinstitutionalisation

The prevalence of psychiatric medication helped initiate deinstitutionalization,[132] the process of discharging patients from psychiatric hospitals to the community.[173] The pressure from the anti-psychiatry movements and the ideology of community treatment from the medical arena helped sustain deinstitutionalization.[132] Thirty-three years after deinstitutionalization started in the United States, only 19% of the patients in state hospitals remained.[132] Mental health professionals envisioned a process wherein patients would be discharged into communities where they could participate in a normal life while living in a therapeutic atmosphere.[132]
Psychiatrists were criticized, however, for failing to develop community-based support and treatment. Community-based facilities were not available because of the political infighting between in-patient and community-based social services, and an unwillingness by social services to dispense funding to provide adequately for patients to be discharged into community-based facilities.

Pharmaceutical industry ties

Psychiatry has greatly benefitted by advances in pharmacotherapy.[3]:110–112[174] However, the close relationship between those prescribing psychiatric medication and pharmaceutical companies, and the risk of a conflict of interest,[174] is also a source of concern. This marketing by the pharmaceutical industry has an influence on practicing psychiatrists, which has an impact on prescription.[174] Child psychiatry is one of the area's in which prescription has grown massively. In the past, it was rare, but nowadays child psychiatrists on a regular basis prescribe psychotropic drugs for children, for instance Ritalin.[3]:110–112

Several prominent academic psychiatrists have refused to disclose financial conflicts of interest, which further undermines public trust in psychiatry.[175] Charles Grassley led a 2008 Congressional Investigation which found that well-known university psychiatrists (such as Joseph Biederman, Charles Nemeroff, and Alan Schatzberg), who had promoted psychoactive drugs, had violated federal and university regulations by secretly receiving large sums of money from the pharmaceutical companies which made the drugs.[21]:21

In an effort to reduce the potential for hidden conflicts of interest between researchers and pharmaceutical companies, the US Government issued a mandate in 2012 requiring that drug manufacturers receiving funds under the Medicare and Medicaid programs collect data, and make public, all gifts to doctors and hospitals.[21]:317

Prisoner experimentation

Prisoners in psychiatric hospitals have been the subjects of experiments involving new medications. Vladimir Khailo of the USSR was an individual exposed to such treatment in the 1980s.[176] However, the involuntary treatment of prisoners by use of psychiatric drugs has not been limited to Khailo, nor the USSR.

Anti-psychiatry

Controversy has often surrounded psychiatry,[3] and the anti-psychiatry message is that psychiatric treatments are ultimately more damaging than helpful to patients. Psychiatry is often thought to be a benign medical practice, but at times is seen by some as a coercive instrument of oppression. Psychiatry is seen to involve an unequal power relationship between doctor and patient, and advocates of anti-psychiatry claim a subjective diagnostic process, leaving much room for opinions and interpretations.[3][177] Every society, including liberal Western society, permits compulsory treatment of mental patients.[3] The World Health Organization (WHO) recognizes that "poor quality services and human rights violations in mental health and social care facilities are still an everyday occurrence in many places", but has recently taken steps to improve the situation globally.[178]
Psychiatry's history involves what some view as dangerous treatments.[3] Electroconvulsive therapy is one of these, which was used widely between the 1930s and 1960s and is still in use today. The brain surgery procedure lobotomy is another practice that was ultimately seen as too invasive and brutal.[177] In the US, between 1939 and 1951, over 50,000 lobotomy operations were performed in mental hospitals. Valium and other sedatives have arguably been over-prescribed, leading to a claimed epidemic of dependence. Concerns also exist for the significant increase in prescription of psychiatric drugs to children.[3][177]

Three authors have come to personify the movement against psychiatry, of which two are or have been practicing psychiatrists. The most influential was R.D. Laing, who wrote a series of best-selling books, including; The Divided Self. Thomas Szasz rose to fame with the book The Myth of Mental Illness. Michael Foucault challenged the very basis of psychiatric practice and cast it as repressive and controlling. The term "anti-psychiatry" itself was coined by David Cooper in 1967.[3][177]

Divergence within psychiatry generated the anti-psychiatry movement in the 1960s and 1970s, and is still present. Issues remaining relevant in contemporary psychiatry are questions of; freedom versus coercion, mind versus brain, nature versus nurture, and the right to be different.[3]

Psychiatric survivors movement

The psychiatric survivors movement[179] arose out of the civil rights ferment of the late 1960s and early 1970s and the personal histories of psychiatric abuse experienced by some ex-patients rather than the intradisciplinary discourse of antipsychiatry.[180] The key text in the intellectual development of the survivor movement, at least in the USA, was Judi Chamberlin's 1978 text, On Our Own: Patient Controlled Alternatives to the Mental Health System.[179][181] Chamberlin was an ex-patient and co-founder of the Mental Patients' Liberation Front.[182] 
Coalescing around the ex-patient newsletter Dendron,[183] in late 1988 leaders from several of the main national and grassroots psychiatric survivor groups felt that an independent, human rights coalition focused on problems in the mental health system was needed. That year the Support Coalition International (SCI) was formed. SCI's first public action was to stage a counter-conference and protest in New York City, in May, 1990, at the same time as (and directly outside of) the American Psychiatric Association's annual meeting.[184] In 2005 the SCI changed its name to Mind Freedom International with David W. Oaks as its director.[180]

Psychopharmacology


From Wikipedia, the free encyclopedia


An arrangement of psychoactive drugs

Psychopharmacology (from Greek ψῡχή, psȳkhē, "breath, life, soul"; φάρμακον, pharmakon, "drug"; and -λογία, -logia) is the scientific study of the effects drugs have on mood, sensation, thinking, and behavior. It is distinguished from neuropsychopharmacology, which emphasizes drug-induced changes in the functioning of cells in the nervous system.[1]

The field of psychopharmacology studies a wide range of substances with various types of psychoactive properties, focusing primarily on the chemical interactions with the brain.

Psychoactive drugs interact with particular target sites or receptors found in the nervous system to induce widespread changes in physiological or psychological functions. The specific interaction between drugs and their receptors is referred to as "drug action", and the widespread changes in physiological or psychological function is referred to as "drug effect". These drugs may originate from natural sources such as plants and animals, or from artificial sources such as chemical synthesis in the laboratory.

Historical overview

Early psychopharmacology


The common muscimol-bearing mushroom Amanita muscaria, also known as the "Fly Agaric"

Not often mentioned or included in the field of psychopharmacology today, are psychoactive substances not identified as useful in modern mental health settings or references. These substances are naturally occurring, but nonetheless psychoactive, and are compounds identified through the work of ethnobotanists and ethnomycologists (and others who study the native use of naturally occurring psychoactive drugs). However, although these substances have been used throughout history by various cultures, and have a profound effect on mentality and brain function, they have not always attained the degree of scrutinous evaluation that lab-made compounds have.
Nevertheless, some, such as psilocybin and mescaline, have provided a basis of study for the compounds that are used and examined in the field today. Hunter-gatherer societies tended to favor psychedelics, dissociatives and deliriants, and today their use can still be observed in many surviving tribal cultures. The exact drug used depends on what the particular ecosystem a given tribe lives in can support, and are typically found growing wild. Such drugs include various psychedelic mushrooms containing psilocybin, muscimol, and muscarine (to name a few), and cacti containing mescaline and other chemicals, along with myriad other psychoactive-chemical-containing plants. These societies generally attach spiritual significance to such drug use, and often incorporate it into their religious practices. With the dawn of the Neolithic and the proliferation of agriculture, new psychoactives came into use as a natural by-product of farming. Among them were opium, cannabis, and alcohol derived from the fermentation of cereals and fruits. Most societies began developing herblores, lists of herbs which were good for treating various physical and mental ailments. For example, St. John's Wort was traditionally prescribed in parts of Europe for depression (in addition to use as a general-purpose tea), and Chinese medicine developed elaborate lists of herbs and preparations. These and various other substances that have an effect on the brain are still used as remedies in many cultures.[2]

Modern psychopharmacology

The dawn of contemporary psychopharmacology marked the beginning of the use of psychiatric drugs to treat psychological illnesses. It brought with it the use of opiates and barbiturates for the management of acute behavioral issues in patients. In the early stages, psychopharmacology was primarily used for sedation. Then with the 1950s came the establishment of chlorpromazine for psychoses, lithium carbonate for mania, and then in rapid succession, the development of tricyclic antidepressants, monoamine oxidase inhibitors, benzodiazepines, among other antipsychotics and antidepressants. A defining feature of this era includes an evolution of research methods, with the establishment of placebo-controlled, double blind studies, and the development of methods for analyzing blood levels with respect to clinical outcome and increased sophistication in clinical trials. The early 1960s revealed a revolutionary model by Julius Axelrod describing nerve signals and synaptic transmission, which was followed by a drastic increase of biochemical brain research into the effects of psychotropic agents on brain chemistry.[3] After the 1960s, the field of psychiatry shifted to incorporate the indications for and efficacy of pharmacological treatments, and began to focus on the use and toxicities of these medications.[4][5] The 1970s and 1980s were further marked by a better understanding of the synaptic aspects of the action mechanisms of drugs. However, the model has its critics, too – notably Joanna Moncrieff and the Critical Psychiatry Network.

Chemical signaling

Neurotransmitters

Psychoactive drugs exert their sensory and behavioral effects almost entirely by acting on neurotransmitters and by modifying one or more aspects of synaptic transmission. Neurotransmitters can be viewed as chemicals through which neurons primarily communicate; psychoactive drugs affect the mind by altering this communication. Drugs may act by 1) serving as a precursor for the neurotransmitter; 2) inhibiting neurotransmitter synthesis; 3) preventing storage of neurotransmitter in the presynaptic vesicle; 4) stimulating or inhibiting neurotransmitter release; 5) stimulating or blocking post-synaptic receptors; 6) stimulating autoreceptors, inhibiting neurotransmitter release; 7) blocking autoreceptors, increasing neurotransmitter release; 8) inhibiting neurotransmission breakdown; or 9) blocking neurotransmitter reuptake by the presynaptic neuron.[1]

Hormones

The other central method through which drugs act is by affecting communications between cells through hormones. Neurotransmitters can usually only travel a microscopic distance before reaching their target at the other side of the synaptic cleft, while hormones can travel long distances before reaching target cells anywhere in the body. Thus, the endocrine system is a critical focus of psychopharmacology because 1) drugs can alter the secretion of many hormones; 2) hormones may alter the behavioral responses to drugs; 3) hormones themselves sometimes have psychoactive properties; and 4) the secretion of some hormones, especially those dependent on the pituitary gland, is controlled by neurotransmitter systems in the brain.[1]

Psychopharmacological substances

Alcohol

Alcohol is a depressant, the effects of which may vary according to dosage amount, frequency, and chronicity. As a member of the sedative-hypnotic class, at the lowest doses, the individual feels relaxed and less anxious. In quiet settings, the user may feel drowsy, but in settings with increased sensory stimulation, individuals may feel uninhibited and more confident. High doses of alcohol rapidly consumed may produce amnesia for the events that occur during intoxication. Other effects include reduced coordination, which leads to slurred speech, impaired fine-motor skills, and delayed reaction time. The effects of alcohol on the body’s neurochemistry are more difficult to examine than some other drugs. This is because the chemical nature of the substance makes it easy to penetrate into the brain, and it also influences the phospholipid bilayer of neurons. This allows alcohol to have a widespread impact on many normal cell functions and modifies the actions of several neurotransmitter systems. Alcohol inhibits glutamate (a major excitatory neurotransmitter in the nervous system) neurotransmission by reducing the effectiveness at the NMDA receptor, which is related to memory loss associated with intoxication. It also modulates the function of GABA, a major inhibitory amino acid neurotransmitter. The reinforcing qualities of alcohol leading to repeated use – and thus also the mechanisms of withdrawal from chronic alcohol use – are partially due to the substance’s action on the dopamine system. This is also due to alcohol’s effect on the opioid systems, or endorphins, that have opiate-like effects, such as modulating pain, mood, feeding, reinforcement, and response to stress.[1]

Antidepressants

Antidepressants reduce symptoms of mood disorders primarily through the regulation of norepinephrine and serotonin (particularly the 5-HT receptors). After chronic use, neurons adapt to the change in biochemistry, resulting in a change in pre- and postsynaptic receptor density and second messenger function.[1]

Monoamine oxidase inhibitors (MAOIs) are the oldest class of antidepressants. They inhibit monoamine oxidase, the enzyme that metabolizes the monoamine neurotransmitters in the presynaptic terminals that are not contained in protective synaptic vesicles. The inhibition of the enzyme increases the amount of neurotransmitter available for release. It increases norepinephrine, dopamine, and 5-HT and thus increases the action of the transmitters at their receptors. MAOIs have been somewhat disfavored because of their reputation for more serious side effects.[1]
Tricyclic antidepressants (TCAs) work through binding to the presynaptic transporter proteins and blocking the reuptake of norepinephrine or 5-HT into the presynaptic terminal, prolonging the duration of transmitter action at the synapse.

Selective serotonin reuptake inhibitors (SSRIs) selectively block the reuptake of serotonin (5-HT) through their inhibiting effects on the sodium/potassium ATP-dependent serotonin transporter in presynaptic neurons. This increases the availability of 5-HT in the synaptic cleft.[6] The main parameters to consider in choosing an antidepressant are side effects and safety. Most SSRIs are available generically and are relatively inexpensive. Older antidepressants, such as the TCAs and MAOIs usually require more visits and monitoring, and this may offset the low expense of the drugs. The SSRIs are relatively safe in overdose and better tolerated than the TCAs and MAOIs for most patients.[6]

Antipsychotics

All antipsychotic substances, except clozapine, are relatively potent postsynaptic dopamine receptor blockers (dopamine antagonists). All of the effective antipsychotics, except clozapine, act on the nigrostriatal system. For an antipsychotic to be effective, it generally requires a dopamine antagonism of 60%-80% of dopamine D2 receptors.[6]
First generation (typical) antipsychotics: Traditional neuroleptics modify several neurotransmitter systems, but their clinical effectiveness is most likely due to their ability to antagonize dopamine transmission by competitively blocking the receptors or by inhibiting dopamine release. The most serious and troublesome side effects of these classical antipsychotics are movement disorders that resemble the symptoms of Parkinson's disease, because the neuroleptics antagonize dopamine receptors broadly, also reducing the normal dopamine-mediated inhibition of cholinergic cells in the striatum.[1]

Second-generation (atypical) antipsychotics: The concept of “atypicality” is from the finding that the second generation antipsychotics (SGAs) had a greater serotonin/dopamine ratio than did earlier drugs, and might be associated with improved efficacy (particularly for the negative symptoms of psychosis) and reduced extrapyramidal side effects. Some of the efficacy of atypical antipsychotics may be due to 5-HT2 antagonism or the blockade of other dopamine receptors. Agents that purely block 5-HT2 or dopamine receptors other than D2 have often failed as effective antipsychotics.[6]

Benzodiazepines

Benzodiazepines are often used to reduce anxiety symptoms, muscle tension, seizure disorders, insomnia, symptoms of alcohol withdrawal, and panic attack symptoms. Their action is primarily on specific benzodiazepine sites on the GABAA receptor. This receptor complex is thought to mediate the anxiolytic, sedative, and anticonvulsant actions of the benzodiazepines.[6] Use of benzodiazepines carries the risk of tolerance (necessitating increased dosage), dependence, and abuse. Taking these drugs for a long period of time can lead to withdrawal symptoms upon abrupt discontinuation.[7]

Hallucinogens

Hallucinogens cause perceptual and cognitive distortions without delirium. The state of intoxication is often called a “trip”. Onset is the first stage after an individual ingests (LSD, psilocybin, or mescaline) or smokes (dimethyltryptamine) the substance. This stage may consist of visual effects, with an intensification of colors and the appearance of geometric patterns that can be seen with one’s eyes closed. This is followed by a plateau phase, where the subjective sense of time begins to slow and the visual effects increase in intensity. The user may experience synesthesia, a crossing-over of sensations (for example, one may “see” sounds and “hear” colors). In addition to the sensory-perceptual effects, hallucinogenic substances may induce feelings of depersonalization, emotional shifts to a euphoric or anxious/fearful state, and a disruption of logical thought. Hallucinogens are classified chemically as either indoleamines (specifically tryptamines), sharing a common structure with serotonin, or as phenethylamines, which share a common structure with norepinephrine. Both classes of these drugs are agonists at the 5-HT2 receptors; this is thought to be the central component of their hallucinogenic properties. Activation of 5-HT2A may be particularly important for hallucinogenic activity. However, repeated exposure to hallucinogens leads to rapid tolerance, likely through down-regulation of these receptors in specific target cells.[1]

Hypnotics

Hypnotics are often used to treat the symptoms of insomnia, or other sleep disorders. Benzodiazepines are still among the most widely prescribed sedative-hypnotics in the United States today. Certain non-benzodiazepine drugs are used as hypnotics as well. Although they lack the chemical structure of the benzodiazepines, their sedative effect is similarly through action on the GABAA receptor. They also have a reputation of being less addictive than benzodiazepines. Melatonin, a naturally-occurring hormone, is often used over the counter (OTC) to treat insomnia and jet lag. This hormone appears to be excreted by the pineal gland early during the sleep cycle and may contribute to human circadian rhythms. Because OTC melatonin supplements are not subject to careful and consistent manufacturing, more specific melatonin agonists are sometimes preferred. They are used for their action on melatonin receptors in the suprachiasmatic nucleus, responsible for sleep-wake cycles. Many barbiturates have or had an FDA-approved indication for use as sedative-hypnotics, but have become less widely used because of their limited safety margin in overdose, their potential for dependence, and the degree of central nervous system depression they induce. The amino-acid L-tryptophan is also available OTC, and seems to be free of dependence or abuse liability. However, it is not as powerful as the traditional hypnotics. Because of the possible role of serotonin in sleep patterns, a new generation of 5-HT2 antagonists are in current development as hypnotics.[6]

Cannabis and the cannabinoids

Cannabis consumption produces a dose-dependent state of intoxication in humans. There is commonly increased blood flow to the skin, which leads to sensations of warmth or flushing, and heart rate is also increased. It also frequently induces increased hunger.[1] Iversen (2000) categorized the subjective and behavioral effects often associated with cannabis into four stages. The first is the "buzz," a brief period of initial responding, where the main effects are lightheadedness or slight dizziness, in addition to possible tingling sensations in the extremities or other parts of the body. The "high" is characterized by feelings of euphoria and exhilaration characterized by mild psychedelia, as well as a sense of disinhibition. If the individual has taken a sufficiently large dose of cannabis, the level of intoxication progresses to the stage of being “stoned,” and the user may feel calm, relaxed, and possibly in a dreamlike state. Sensory reactions may include the feeling of floating, enhanced visual and auditory perception, visual illusions, or the perception of the slowing of time passage, which are somewhat psychedelic in nature.[8]
There exist two primary CNS cannabinoid receptors, on which marijuana and the cannabinoids act. Both the CB1 receptor and CB2 receptor are found in the brain. The CB2 receptor is also found in the immune system. CB1 is expressed at high densities in the basal ganglia, cerebellum, hippocampus, and cerebral cortex. Receptor activation can inhibit cAMP formation, inhibit voltage-sensitive calcium ion channels, and activate potassium ion channels. Many CB1 receptors are located on axon terminals, where they act to inhibit the release of various neurotransmitters. In combination, these drug actions work to alter various functions of the central nervous system including the motor system, memory, and various cognitive processes.[1]

Opiates

The opiate drugs, which include drugs like heroin, morphine, and oxycodone, belong to the class of narcotic analgesics, which reduce pain without producing unconsciousness, but do produce a sense of relaxation and sleep, and at high doses, may result in coma and death. The ability of opiates (both endogenous and exogenous) to relieve pain depends on a complex set of neuronal pathways at the spinal cord level, as well as various locations above the spinal cord. Small endorphin neurons in the spinal cord act on receptors to decrease the conduction of pain signals from the spinal cord to higher brain centers. Descending neurons originating in the periaqueductal gray give rise to two pathways that further block pain signals in the spinal cord. The pathways begin in the locus coeruleus (noradrenaline) and the nucleus of raphe (serotonin). Similar to other abused substances, opiate drugs increase dopamine release in the nucleus accumbens.[1] Opiates are among the most physically addictive of all psychoactive drugs, and can lead to painful withdrawal symptoms if discontinued abruptly after regular use.

Stimulants

Cocaine is one of the more common stimulants, and is a complex drug that interacts with various neurotransmitter systems. It commonly cause heightened alertness, increased confidence, feelings of exhilaration, reduced fatigue, and a generalized sense of well-being. The effects of cocaine are similar to those of the amphetamines, though cocaine tends to have a shorter duration of effect. In high doses and/or with prolonged use, cocaine can result in a number of negative effects as well, including irritability, anxiety, exhaustion, total insomnia, and even psychotic symptomatology. Most of the behavioral and physiological actions of cocaine can be explained by its ability to block the reuptake of the two catecholamines, dopamine and norepinephrine, as well as serotonin. Cocaine binds to transporters that normally clear these transmitters from the synaptic cleft, inhibiting their function. This leads to increased levels of neurotransmitter in the cleft and transmission at the synapses.[1] Based on in-vitro studies using rat brain tissue, cocaine binds most strongly to the serotonin transporter, followed by the dopamine transporter, and then the norepinephrine transporter.[9]

Amphetamines tend to cause the same behavioral and subjective effects of cocaine. Various forms of amphetamine are commonly used to treat the symptoms of attention deficit hyperactivity disorder (ADHD) and narcolepsy, or are used recreationally. Amphetamine and methamphetamine are indirect agonists of the catecholaminergic systems. They block catecholamine reuptake, in addition to releasing catecholamines from nerve terminals. There is evidence that dopamine receptors play a central role in the behavioral responses of animals to cocaine, amphetamines, and other psychostimulant drugs. One action causes the dopamine molecules to be released from inside the vesicles into the cytoplasm of the nerve terminal, which are then transported outside by the mesolimbic dopamine pathway to the nucleus accumbens. This plays a key role in the rewarding and reinforcing effects of cocaine and amphetamine in animals, and is the primary mechanism for amphetamine dependence.

Psychopharmacological research

In psychopharmacology, researchers are interested in any substance that crosses the blood–brain barrier and thus has an effect on behavior, mood or cognition. Drugs are researched for their physiochemical properties, physical side effects, and psychological side effects. Researchers in psychopharmacology study a variety of different psychoactive substances that include alcohol, cannabinoids, club drugs, psychedelics, opiates, nicotine, caffeine, psychomotor stimulants, inhalants, and anabolic-androgenic steroids. They also study drugs used in the treatment of affective and anxiety disorders, as well as schizophrenia.
Clinical studies are often very specific, typically beginning with animal testing, and ending with human testing. In the human testing phase, there is often a group of subjects, one group is given a placebo, and the other is administered a carefully measured therapeutic dose of the drug in question. After all of the testing is completed, the drug is proposed to the concerned regulatory authority (e.g. the U.S. FDA), and is either commercially introduced to the public via prescription, or deemed safe enough for over the counter sale.

Though particular drugs are prescribed for specific symptoms or syndromes, they are usually not specific to the treatment of any single mental disorder. Because of their ability to modify the behavior of even the most disturbed patients, the antipsychotic, antianxiety, and antidepressant agents have greatly affected the management of the hospitalized mentally ill, enabling hospital staff to devote more of their attention to therapeutic efforts and enabling many patients to lead relatively normal lives outside of the hospital.[citation needed]

A somewhat controversial application of psychopharmacology is "cosmetic psychiatry": persons who do not meet criteria for any psychiatric disorder are nevertheless prescribed psychotropic medication. The antidepressant Wellbutrin is then prescribed to increase perceived energy levels and assertiveness while diminishing the need for sleep. The antihypertensive compound Inderal is sometimes chosen to eliminate the discomfort of day-to-day "normal" anxiety . Prozac in nondepressed people can produce a feeling of generalized well-being. Mirapex, a treatment for restless leg syndrome, can dramatically increase libido in women. These and other off-label life-style applications of medications are not uncommon. Although occasionally reported in the medical literature no guidelines for such usage have been developed.[10] There is also a potential for the misuse of prescription psychoactive drugs by elderly persons, who may have multiple drug prescriptions.[11][12]

Pharmacology


From Wikipedia, the free encyclopedia


A variety of topics involved with pharmacology, including neuropharmacology, renal pharmacology, human metabolism, intracellular metabolism, and intracellular regulation
For the Wikipedia Manual of Style for Pharmacology, see WP:DRUGLIKE

Pharmacology (from Greek φάρμακον, pharmakon, "poison" in classic Greek; "drug" in modern Greek; and -λογία, -logia "study of", "knowledge of") is the branch of medicine and biology concerned with the study of drug action,[1] where a drug can be broadly defined as any man-made, natural, or endogenous (within the body) molecule which exerts a biochemical and/or physiological effect on the cell, tissue, organ, or organism (sometimes the word pharmacon is used as a term to encompass these endogenous and exogenous bioactive species). More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function. If substances have medicinal properties, they are considered pharmaceuticals.

The field encompasses drug composition and properties, synthesis and drug design, molecular and cellular mechanisms, organ/systems mechanisms, signal transduction/cellular communication, molecular diagnostics, interactions, toxicology, chemical biology, therapy, and medical applications and antipathogenic capabilities. The two main areas of pharmacology are pharmacodynamics and pharmacokinetics. The former studies the effects of the drug on biological systems, and the latter the effects of biological systems on the drug. In broad terms, pharmacodynamics discusses the chemicals with biological receptors, and pharmacokinetics discusses the absorption, distribution, metabolism, and excretion (ADME) of chemicals from the biological systems. Pharmacology is not synonymous with pharmacy and the two terms are frequently confused. Pharmacology, a biomedical science, deals with the research, discovery, and characterization of chemicals which show biological effects and the elucidation of cellular and organismal function in relation to these chemicals. In contrast, pharmacy, a health services profession, is concerned with application of the principles learned from pharmacology in its clinical settings; whether it be in a dispensing or clinical care role. In either field, the primary contrast between the two are their distinctions between direct-patient care, for pharmacy practice, and the science-oriented research field, driven by pharmacology.

The origins of clinical pharmacology date back to the Middle Ages in Avicenna's The Canon of Medicine, Peter of Spain's Commentary on Isaac, and John of St Amand's Commentary on the Antedotary of Nicholas.[2] Clinical pharmacology owes much of its foundation to the work of William Withering.[3] Pharmacology as a scientific discipline did not further advance until the mid-19th century amid the great biomedical resurgence of that period.[4] Before the second half of the nineteenth century, the remarkable potency and specificity of the actions of drugs such as morphine, quinine and digitalis were explained vaguely and with reference to extraordinary chemical powers and affinities to certain organs or tissues.[5] The first pharmacology department was set up by Rudolf Buchheim in 1847, in recognition of the need to understand how therapeutic drugs and poisons produced their effects.[4]

Early pharmacologists focused on natural substances, mainly plant extracts. Pharmacology developed in the 19th century as a biomedical science that applied the principles of scientific experimentation to therapeutic contexts.[6] Today Pharmacologists harness the power of genetics, molecular biology, chemistry, and other advanced tools to transform information about molecular mechanisms and targets into therapies directed against disease, defects or pathogens, and create methods for preventative care, diagnostics, and ultimately personalized medicine.

Divisions

The discipline of pharmacology can be divided into many sub disciplines each with a specific focus.

Clinical pharmacology

Clinical pharmacology is the basic science of pharmacology with an added focus on the application of pharmacological principles and methods in the medical clinic and towards patient care and outcomes.

Neuropharmacology

Neuropharmacology is the study of the effects of medication on central and peripheral nervous system functioning.

Psychopharmacology

Psychopharmacology is the study of the effects of medication on the psyche (psychology), observing changed behaviors of the body and mind, and how molecular events are manifest in a measurable behavioral form. This is similar to the closely related ethopharmacology.

Pharmacogenetics

Pharmacogenetics is clinical testing of genetic variation that gives rise to differing response to drugs.

Pharmacogenomics

Pharmacogenomics is the application of genomic technologies to drug discovery and further characterization of older drugs.

Identification of the genetic basis for polymorphic expression of a gene is done through intronic or exomic single-nucleotide polymorphisms (SNPs) which abolishes the need for different mechanisms for explaining the variability in drug metabolism. SNPs based variations in membrane receptors lead to multidrug resistance (MDR) and the drug–drug interactions. Even drug induced toxicity and many adverse effects can be explained by GWA studies. The multitude of SNPs help in understanding gene pharmacokinetic (PK) or pharmacodynamic (PD) pathways.[7]

Pharmacoepidemiology

Pharmacoepidemiology is the study of the effects of drugs in large numbers of people.

Toxicology

Toxicology is the study of the adverse effects, molecular targets, and characterization of drugs or any chemical substance in excess (including those beneficial in lower doses).

Theoretical pharmacology

Theoretical pharmacology is the study of metrics in pharmacology.

Posology

Posology is the study of how medicines are dosed. It also depends upon various factors including age, climate, weight, sex, and time of administration .

Pharmacognosy

Pharmacognosy is a branch of pharmacology dealing especially with the composition, use, and development of medicinal substances of biological origin and especially medicinal substances obtained from plants.

Behavioral pharmacology

Behavioral pharmacology, also referred to as psychopharmacology or ethopharmacology, is an interdisciplinary field which studies behavioral effects of psychoactivedrugs. It incorporates approaches and techniques from neuropharmacology, animal behavior and behavioral neuroscience, and is interested in the behavioral and neurobiological mechanisms of action of psychoactive drugs. Another goal of behavioral pharmacology is to develop animal behavioral models to screen chemical compounds with therapeutic potentials. People in this field (called behavioral pharmacologists) typically use small animals (e.g. rodents) to study psychotherapeutic drugs such as antipsychotics, antidepressants and anxiolytics, and drugs of abuse such as nicotine, cocaine, methamphetamine, etc.

Environmental pharmacology

Environmental pharmacology is a new discipline.[8] Focus is being given to understand gene–environment interaction, drug-environment interaction and toxin-environment interaction. There is a close collaboration between environmental science and medicine in addressing these issues, as healthcare itself can be a cause of environmental damage or remediation. Human health and ecology are intimately related. Demand for more pharmaceutical products may place the public at risk through the destruction of species. The entry of chemicals and drugs into the aquatic ecosystem is a more serious concern today. In addition, the production of some illegal drugs pollutes drinking water supply by releasing carcinogens.[9] This field is intimately linked with Public Health fields.

Scientific background

The study of chemicals requires intimate knowledge of the biological system affected. With the knowledge of cell biology and biochemistry increasing, the field of pharmacology has also changed substantially. It has become possible, through molecular analysis of receptors, to design chemicals that act on specific cellular signaling or metabolic pathways by affecting sites directly on cell-surface receptors (which modulate and mediate cellular signaling pathways controlling cellular function).

A chemical has, from the pharmacological point-of-view, various properties. Pharmacokinetics describes the effect of the body on the chemical (e.g. half-life and volume of distribution), and pharmacodynamics describes the chemical's effect on the body (desired or toxic).

When describing the pharmacokinetic properties of the chemical that is the active ingredient or active pharmaceutical ingredient (API), pharmacologists are often interested in L-ADME:
  • Liberation – How is the API disintegrated (for solid oral forms (breaking down into smaller particles)), dispersed, or dissolved from the medication?
  • Absorption – How is the API absorbed (through the skin, the intestine, the oral mucosa)?
  • Distribution – How does the API spread through the organism?
  • Metabolism – Is the API converted chemically inside the body, and into which substances. Are these active (as well)? Could they be toxic?
  • Excretion – How is the API excreted (through the bile, urine, breath, skin)?
Medication is said to have a narrow or wide therapeutic index or therapeutic window. This describes the ratio of desired effect to toxic effect. A compound with a narrow therapeutic index (close to one) exerts its desired effect at a dose close to its toxic dose. A compound with a wide therapeutic index (greater than five) exerts its desired effect at a dose substantially below its toxic dose. Those with a narrow margin are more difficult to dose and administer, and may require therapeutic drug monitoring (examples are warfarin, some antiepileptics, aminoglycoside antibiotics). Most anti-cancer drugs have a narrow therapeutic margin: toxic side-effects are almost always encountered at doses used to kill tumors.

Medicine development and safety testing

Development of medication is a vital concern to medicine, but also has strong economical and political implications. To protect the consumer and prevent abuse, many governments regulate the manufacture, sale, and administration of medication. In the United States, the main body that regulates pharmaceuticals is the Food and Drug Administration and they enforce standards set by the United States Pharmacopoeia. In the European Union, the main body that regulates pharmaceuticals is the EMEA and they enforce standards set by the European Pharmacopoeia.

The metabolic stability and the reactivity of a library of candidate drug compounds have to be assessed for drug metabolism and toxicological studies. Many methods have been proposed for quantitative predictions in drug metabolism; one example of a recent computational method is SPORCalc.[10] If the chemical structure of a medicinal compound is altered slightly, this could slightly or dramatically alter the medicinal properties of the compound depending on the level of alteration as it relates to the structural composition of the substrate or receptor site on which it exerts its medicinal effect, a concept referred to as the structural activity relationship (SAR). This means that when a useful activity has been identified, chemists will make many similar compounds called analogues, in an attempt to maximize the desired medicinal effect(s) of the compound. This development phase can take anywhere from a few years to a decade or more and is very expensive.[11]

These new analogues need to be developed. It needs to be determined how safe the medicine is for human consumption, its stability in the human body and the best form for delivery to the desired organ system, like tablet or aerosol. After extensive testing, which can take up to 6 years, the new medicine is ready for marketing and selling.[11]

As a result of the long time required to develop analogues and test a new medicine and the fact that of every 5000 potential new medicines typically only one will ever reach the open market, this is an expensive way of doing things, often costing over 1 billion dollars. To recoup this outlay pharmaceutical companies may do a number of things:[11]
  • Carefully research the demand for their potential new product before spending an outlay of company funds.[11]
  • Obtain a patent on the new medicine preventing other companies from producing that medicine for a certain allocation of time.[11]

Drug legislation and safety

In the United States, the Food and Drug Administration (FDA) is responsible for creating guidelines for the approval and use of drugs. The FDA requires that all approved drugs fulfill two requirements:
  1. The drug must be found to be effective against the disease for which it is seeking approval (where 'effective' means only that the drug performed better than placebo or competitors in at least two trials).
  2. The drug must meet safety criteria by being subject to animal and controlled human testing.
Gaining FDA approval usually takes several years to attain. Testing done on animals must be extensive and must include several species to help in the evaluation of both the effectiveness and toxicity of the drug. The dosage of any drug approved for use is intended to fall within a range in which the drug produces a therapeutic effect or desired outcome.[12]

The safety and effectiveness of prescription drugs in the U.S. is regulated by the federal Prescription Drug Marketing Act of 1987.

The Medicines and Healthcare products Regulatory Agency (MHRA) has a similar role in the UK.

Education

Students of pharmacology are trained as biomedical scientists, studying the effects of drugs on living organisms. This can lead to new drug discoveries, as well as a better understanding of the way in which the human body works.
Students of pharmacology must have detailed working knowledge of aspects in physiology, pathology and chemistry. During a typical degree they will cover areas such as (but not limited to) biochemistry, cell biology, basic physiology, genetics & the Central Dogma, medical microbiology, neuroscience, and depending on the department's interests, bio-organic chemistry and/or chemical biology.

Modern Pharmacology is highly interdisciplinary. Graduate programs accept students from most biological and chemical backgrounds. With the increasing drive towards biophysical and computational research to describe systems, pharmacologists may even consider themselves mainly physical scientists. In many instances, Analytical Chemistry is closely related to the studies and needs of pharmacological research. Therefore, many institutions will include pharmacology under a Chemistry or Biochemistry Department, especially if a separate Pharmacology Dept. does not exist. What makes an institutional department independent of another, or exist in the first place, is usually an artifact of historical times.

Whereas a pharmacy student will eventually work in a pharmacy dispensing medications, a pharmacologist will typically work within a laboratory setting. Careers for a pharmacologist include academic positions (medical and non-medical), governmental positions, private industrial positions, science writing, scientific patents and law, consultation, biotech and pharmaceutical employment, the alcohol industry, food industry, forensics/law enforcement, public health, and environmental/ecological sciences.

Entropy (information theory)

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Entropy_(information_theory) In info...