Prevention of mental disorders are measures that try to decrease the chances of a mental disorder
occurring. A 2004 WHO report stated that "prevention of these disorders
is obviously one of the most effective ways to reduce the [disease]
burden."
The 2011 European Psychiatric Association
(EPA) guidance on prevention of mental disorders states "There is
considerable evidence that various psychiatric conditions can be
prevented through the implementation of effective evidence-based
interventions."
A 2011 UK Department of Health
report on the economic case for mental health promotion and mental
illness prevention found that "many interventions are outstandingly good
value for money, low in cost and often become self-financing over time,
saving public expenditure".
In 2016, the National Institute of Mental Health re-affirmed prevention as a research priority area.
Methods
Parenting
Parenting may affect the child's mental health, and evidence suggests that helping parents to be more effective with their children can address mental health needs.
Assessing parenting capability has been raised in child protection and other contexts. Delaying of potential very young pregnancies could lead to better mental health causal risk factors such as improved parenting skills and more stable homes, and various approaches have been used to encourage such behaviour change. Some countries run conditional cash transfer welfare programs where payment is conditional on behaviour of the recipients. Compulsory contraception has been used to prevent future mental illness.
Use of cognitive behavioral therapy (CBT)
with people at risk has significantly reduced the number of episodes of
generalized anxiety disorder and other anxiety symptoms, and also given
significant improvements in explanatory style, hopelessness, and
dysfunctional attitudes. In 2014 the UK National Institute for Health and Care Excellence (NICE) recommended preventive CBT for people at risk of psychosis.
As of 2018, some health providers now advocate pre-emptive use of CBT to prevent worsening of mental illnesses.
Sahajameditators scored above control groups for emotional well-being and mental health measures on SF-36
ratings, leading to proposed use for mental illness prevention,
although this result could be due to meditators having other
characteristics leading to good mental health, such as higher general
self care.
Internet- and mobile-based interventions
A
review found that a number of studies have shown that internet- and
mobile-based interventions can be effective in preventing mental
disorders.
Specific diseases
Depression
For depressive disorders, when people participated in interventions, some studies show the number of new cases is reduced by 22% to 38%. These interventions included CBT. Such interventions also save costs. Depression prevention continues to be called for.
use of cognitive behavioral therapy
(CBT) with people at risk has significantly reduced the number of
episodes of generalized anxiety disorder and other anxiety symptoms, and
also given significant improvements in explanatory style, hopelessness,
and dysfunctional attitudes.
Other interventions (parental inhibition reduction, behaviourism,
parental modelling, problem-solving and communication skills) have also
produced significant benefits. People with subthreshold panic disorder were found to benefit from use of CBT.
for older people, a stepped-care intervention (watchful waiting, CBT
and medication if appropriate) achieved a 50% lower incidence rate of
depression and anxiety disorders in a patient group aged 75 or older.
for younger people, it has been found that teaching CBT in schools reduced anxiety in children,
and a review found that most universal, selective and indicated
prevention programs are effective in reducing symptoms of anxiety in
children and adolescents.
for university students mindfulness has been shown to reduce subsequent anxiety.
Psychosis
In those at high risk there is tentative evidence that psychosis incidence may be reduced with the use of CBT or other types of therapy. In 2014 the UK National Institute for Health and Care Excellence (NICE) recommended preventive CBT for people at risk of psychosis.
There is also tentative evidence that treatment may help those with early symptoms. Antipsychotic medications are not recommended for preventing psychosis.
For schizophrenia, one study of preventative CBT showed a positive effect and another showed neutral effect.
Targeted vs universal
There
has been an historical trend among public health professionals to
consider targeted programmes. However identification of high risk groups
can increase stigma, in turn meaning that the targeted people do not
engage. Thus policy recommends universal programs, with resources within
such programs weighted towards high risk groups.
Universal prevention (aimed at a population that has no increased
risk for developing a mental disorder, such as school programs or mass
media campaigns) need very high numbers of people to show effect
(sometimes known as the "power" problem). Approaches to overcome this
are (1) focus on high-incidence groups (e.g. by targeting groups with
high risk factors), (2) use multiple interventions to achieve greater,
and thus more statistically valid, effects, (3) use cumulative
meta-analyses of many trials, and (4) run very large trials.
History
History of mental illness prevention strategies
In 2018 the University of Birmingham
Mental Health Policy Commission focused on prevention, including the
challenges of funding given the shortness of political cycles versus the
longer paybacks of prevention.
In 2018 11 European researchers published a review of mental illness prevention stating that "Increasing
evidence suggests that preventive interventions in psychiatry that are
feasible, safe, and cost-effective could translate into a broader focus
on prevention in our field." and that "Gaps between knowledge, policy, and practice need to be bridged."
In 2018 Massachusetts announced a mental health strategy including many prevention elements. The executive summary began "Behavioral health promotion and upstream prevention works."
In 2017 the Australian Government funded a new Centre for Research Excellence in Prevention of Anxiety and Depression.
the UK NHS Mental Health Taskforce included 'preventing mental
health' in its 3 Priorities, focusing on children and young ages, and
the importance of employment.
the UK NGO Mind produced public mental health recommendations for more prevention.
In 2015:
the Hunter Institute of mental health in Australia published its "Prevention First" strategic framework for prevention.
the UK NGO Mental Health Foundation published a review of prevention research, paving the way for prevention strategies.
the official journal of the World Psychiatric Association included a survey of public mental health which concluded "the
evidence base for public mental health interventions is convincing, and
the time is now ripe to move from knowledge to action".
In 2013 the Faculty of Public Health, the UK professional body for public health professionals, produced its "Better Mental Health for All" resource, which aims at "the promotion of mental wellbeing and the primary prevention of mental illness".
In 2012, Mind, the UK mental health NGO, included "Staying well; Support people likely to develop mental health problems, to stay well." as its first goal for 2012–16.
The 2011 mental health strategy of Manitoba (Canada) included
intents to (i) reduce risk factors associated with mental ill-health and
(ii) increase mental health promotion for both adults and children.
The 2011 US National Prevention Strategy included mental and
emotional well-being, with recommendations including (i) better
parenting and (ii) early intervention.
Australia's mental health plan for 2009–14 included "Prevention and Early Intervention" as priority 2.
The 2008 EU "Pact for Mental Health" made recommendations for youth
and education including (i) promotion of parenting skills, (ii)
integration of socio-emotional learning into education curricular and
extracurricular activities, and (iii) early intervention throughout the
educational system.
The 2006 Canadian "Out of the Shadows at last" included a section on prevention.
History of mental illness prevention programmes
Historically
prevention has been a very small part of the spend of mental health
systems. For instance the 2009 UK Department of Health analysis of
prevention expenditure did not include any apparent spend on mental
health. The situation is the same in research.
However more recently some prevention programmes have been
proposed or implemented. Prevention programmes can include public health
policies to raise general health, creating supportive environments,
strengthening communities, developing personal skills, and reorienting
services.
In 2017 the UK PHE and LSE produced research showing short payback periods for a number of prevention interventions.
In 2017 the Scotland Mental Health Strategy included prevention, including a focus on improving parenting skills.
In 2016, the UK Education Policy Institute
advocated prevention through increased mental health literacy, better
parenting and improving children's resilience and digital world skills.
In 2012 the UK Schizophrenia Commission recommended "a
preventative strategy for psychosis including promoting protective
factors for mental wellbeing and reducing risks such as cannabis use in
early adolescence."
In 2010 the European Union DataPrev database was launched. It states "A
healthy start is crucial for mental health and wellbeing throughout
life, with parenting being the single most important factor," and recommends a range of interventions.
In 2009 the US National Academies publication on preventing mental,
emotional, and behavioral disorders among young people focused on recent
research and program experience and stated that "A number of promotion and prevention programs are now available that should be considered for broad implementation." A 2011 review of this by the authors said "A scientific base of evidence shows that we can prevent many mental, emotional, and behavioral disorders before they begin" and made recommendations including
supporting the mental health and parenting skills of parents,
encouraging the developmental competencies of children and
using preventive strategies particularly for children at risk (such
as children of parents with mental illness, or with family stresses such
as divorce or job loss).
In India the 1982 National Mental health Programme included prevention, but implementation has been slow, particularly of prevention elements.
It is already known that home visiting programs for pregnant
women and parents of young children can produce replicable effects on
children's general health and development in a variety of community
settings. Similarly positive benefits from social and emotional education are well proven.
Research has shown that risk assessment and behavioral interventions in
pediatric clinics reduced abuse and neglect outcomes for young
children. Early childhood home visitation also reduced abuse and neglect, but results were inconsistent.
Issues in implementation
Prevention
programs can face issues in (i) ownership, because health systems are
typically targeted at current suffering, and (ii) funding, because
program benefits come on longer timescales than the normal political and
management cycle. Assembling collaborations of interested bodies appears to be an effective model for achieving sustained commitment and funding.
Mumps is highly contagious and spreads rapidly among people living in close quarters. The virus is transmitted by respiratory droplets or direct contact with an infected person. Only humans get and spread the disease. People are infectious from about 7 days before onset of parotid inflammation to about 8 days after. Once an infection has run its course, a person is typically immune for life. Reinfection is possible, but the ensuing infection tends to be mild. Diagnosis is usually suspected due to parotid swelling and can be confirmed by isolating the virus on a swab of the parotid duct.
Testing for IgM antibodies in the blood is simple and may be useful;
however, it can be falsely negative in those who have been immunized.
Mumps is preventable by two doses of the mumps vaccine. Most of the developed world includes it in their immunization programs, often in combination with measles, rubella, and varicella vaccine. Countries that have low immunization rates may see an increase in cases among older age groups and thus worse outcomes. No specific treatment is known. Efforts involve controlling symptoms with pain medication such as paracetamol (acetaminophen). Intravenous immunoglobulin may be useful in certain complications. Hospitalization may be required if meningitis or pancreatitis develops. About one in 10,000 people who are infected die.
Without immunization, about 0.1 to 1.0% of the population is affected per year. Widespread vaccination has resulted in a more than 90% decline in rates of disease. Mumps is more common in the developing world, where vaccination is less common. Outbreaks, however, may still occur in a vaccinated population. Before the introduction of a vaccine, mumps was a common childhood disease worldwide. Larger outbreaks of disease typically occurred every 2 to 5 years. Children between the ages of 5 and 9 were most commonly affected. Among immunized populations, those in their early 20s often are affected. Around the equator,
it often occurs all year round, while in the more northerly and
southerly regions of the world, it is more common in the winter and
spring. Painful swelling of the parotid glands and testicles was described by Hippocrates in the fifth century BCE.
Signs and symptoms
Mumps is usually preceded by a set of prodromal symptoms, including low-grade fever, headache, and feeling generally unwell. This is followed by progressive swelling of one or both parotid glands. Parotid gland swelling usually lasts about a week. Other symptoms of mumps can include dry mouth, sore face and/or ears, and difficulty speaking.
Complications
Painful testicular inflammation develops in 15–40% of men who have completed puberty and contract the mumps virus.
This testicular inflammation is generally one-sided (both testicles are
swollen in 15–30% of mumps orchitis cases) and typically occurs about
10 days after the parotid gland becomes inflamed. Testicular swelling has been documented as late as 6 weeks after parotid-gland swelling. Decreased fertility is an uncommon consequence of testicular inflammation from mumps and infertility is rare.
Studies have reached differing conclusions regarding whether
infection with the mumps virus during pregnancy leads to an increased
rate of spontaneous abortion.
Before vaccination, about 10% of cases of aseptic meningitis were due to mumps. The symptoms generally resolve within 10 days. Infection of the brain itself (encephalitis) occurs in between 0.02 and 0.3% of cases.
Ovarian inflammation occurs in about 5% percent of adolescent and adult females.
Brain inflammation is very rare, and fatal in about 1% of the cases when it occurs.
Profound (91 dB or more) but rare sensorineural hearing loss can occur, which can be uni- or bilateral. Acute unilateral deafness occurs in about 0.005% of cases.
Cause
The mumps virus is an enveloped, single-stranded, linear negative-senseRNA virus of the genus Rubulavirus and family Paramyxovirus.
The genome consists of 15,384 bases encoding nine proteins. Proteins
involved in viral replication are the nucleoprotein, phosphoprotein, and
polymerase protein while the genomic RNA forms the ribonucleocapsid. Humans are the only natural host for the virus.
Mumps is spread from person to person through contact with respiratory secretions, such as saliva from an infected person.
When an infected person coughs or sneezes, the droplets aerosolize and
can enter the eyes, nose, or mouth of another person. Mumps can also be
spread by sharing eating utensils or cups.
The virus can also survive on surfaces and then be spread after contact
in a similar manner. A person infected with mumps is contagious from
around 7 days before the onset of symptoms until about 8 days after
symptoms start. The incubation period (time until symptoms begin) can be from 12–25 days, but is typically 16–18 days.
About 20-40% of persons infected with the mumps virus do not show
symptoms, so being infected and spreading the virus without knowing it
is possible.
Diagnosis
During
an outbreak, a diagnosis can be made by determining recent exposure and
parotitis. However, when the disease incidence is low, other infectious
causes of parotitis should be considered, such as HIV, coxsackievirus, and influenza. Some viruses such as enteroviruses may cause aseptic meningitis that is very clinically similar to mumps.
A physical examination confirms the presence of the swollen
glands. Usually, the disease is diagnosed on clinical grounds, and no
confirmatory laboratory testing is needed. If uncertainty exists about
the diagnosis, a test of saliva or blood may be carried out; a newer diagnostic confirmation, using real-time nested polymerase chain reaction technology, has also been developed. As with any inflammation of the salivary glands, the serum level of the enzyme amylase is often elevated.
Prevention
The most common preventive measure against mumps is a vaccination with a mumps vaccine, invented by American microbiologist Maurice Hilleman at Merck. The vaccine may be given separately or as part of the MMR vaccine or MMRV vaccine. The World Health Organization
(WHO) recommends the use of mumps vaccines in all countries with
well-functioning childhood vaccination programmes. In the United
Kingdom, they are routinely given to children at age 13 months with a
booster at 3–5 years (preschool). The American Academy of Pediatrics recommends the routine administration of MMR vaccine at ages 12–15 months and at 4–6 years.
In some locations, the vaccine is given again between 4 and 6 years of
age, or between 11 and 12 years of age if not previously given. The efficacy of the vaccine depends on its strain, but is usually around 80%.
The Jeryl Lynn strain is most commonly used in developed countries,
but has been shown to have reduced efficacy in epidemic situations. The
Leningrad-Zagreb strain commonly used in developing countries appears to
have superior efficacy in epidemic situations.
Because of the outbreaks within college and university settings,
many governments have established vaccination programs to prevent
large-scale outbreaks. In Canada, provincial governments and the Public
Health Agency of Canada have all participated in awareness campaigns to
encourage students ranging from grade one to college and university to
get vaccinated.
Before the introduction of the mumps vaccine, the mumps virus was the leading cause of viral meningoencephalitis in the United States. However, encephalitis occurs rarely (less than two per 100,000).
In one of the largest studies in the literature, the most common
symptoms of mumps meningoencephalitis were found to be fever (97%),
vomiting (94%), and headache (88.8%).
The mumps vaccine was introduced into the United States in December
1967: since its introduction, a steady decrease in the incidence of
mumps has occurred, with 151,209 cases of mumps reported in 1968. From
2001 to 2008, the case average was only 265 per year, excluding an
outbreak of less than 6000 cases in 2006 attributed largely to
university contagion in young adults.
Management
The treatment of mumps is supportive. Symptoms may be relieved by the application of intermittent ice or heat to the affected neck/testicular area and by acetaminophen for pain relief. Warm saltwater gargles, soft foods, and extra fluids may also help relieve symptoms. Acetylsalicylic acid (aspirin) is not used to treat children due to the risk of Reye syndrome.
No effective postexposure recommendation is made to prevent secondary transmission, nor is the postexposure use of vaccine or immunoglobulin effective.
Mumps is considered most contagious in the 5 days after the onset of symptoms, and isolation
is recommended during this period. In someone who has been admitted to
the hospital, standard and droplet precautions are needed. People who
work in healthcare cannot work for 5 days.
Epidemiology
In the United States, typically between a few hundred and few thousand cases occur in a year.
History
Mumps has been known to humans since antiquity. It was mentioned by Hippocrates in his Of the Epidemics written in 400 BC, wherein he described the painful swelling of the parotid glands and testicles. The disease was first described scientifically as late as 1790 by a British physician Robert Hamilton (1721–1793) in the Transactions of the Royal Society of Edinburgh. The disease was one of the most medically significant diseases among the armies involved in the fighting both World War I and World War II.
A number of attempts to prove that mumps is contagious failed. Its
contagiousness was finally proved in 1934 by Claude D. Johnson and
Ernest William Goodpasture (1886–1960), who demonstrated that mumps was
transmitted by a filterable virus.
Contemporary illustration of the 1868 Washita Massacre by the 7th Cavalry against Black Kettle's band of Cheyennes, during the American Indian Wars.
Violence and conflict with colonists were also important causes of the
decline of certain indigenous American populations since the 16th
century.
The population figure of indigenous peoples of the Americas before the 1492 Spanish voyage of Christopher Columbus
has proven difficult to establish. Scholars rely on archaeological data
and written records from European settlers. Most scholars writing at
the end of the 19th century estimated that the pre-Columbian
population was as low as 10 million; by the end of the 20th century
most scholars gravitated to a middle estimate of around 50 million, with
some historians arguing for an estimate of 100 million or more. Contact with the Europeans led to the European colonization of the Americas, in which millions of immigrants from Europe eventually settled in the Americas.
The population of African and Eurasian peoples in the Americas grew steadily, while the indigenous population plummeted. Eurasian diseases such as influenza, pneumonic plagues, and smallpox
devastated the Native Americans, who did not have immunity to them.
Conflict and outright warfare with Western European newcomers and other
American tribes further reduced populations and disrupted traditional
societies. The extent and causes of the decline have long been a subject
of academic debate, along with its characterization as a genocide.
Population overview
Given
the fragmentary nature of the evidence, even semi-accurate
pre-Columbian population figures are impossible to obtain. Scholars have
varied widely on the estimated size of the indigenous populations prior
to colonization and on the effects of European contact. Estimates are made by extrapolations from small bits of data. In 1976, geographer William Denevan
used the existing estimates to derive a "consensus count" of about
54 million people. Nonetheless, more recent estimates still range
widely.
Using an estimate of approximately 37 million people in Mexico, Central and South America in 1492 (including 6 million in the Aztec Empire, 5-10 million in the Mayan States, 11 million in what is now Brazil, and 12 million in the Inca Empire), the lowest estimates give a death toll due from disease of 80% by the end of the 17th century (nine million people in 1650).
Latin America would match its 15th-century population early in the 19th
century; it numbered 17 million in 1800, 30 million in 1850, 61 million
in 1900, 105 million in 1930, 218 million in 1960, 361 million in 1980,
and 563 million in 2005. In the last three decades of the 16th century, the population of present-day Mexico dropped to about one million people. The Maya
population is today estimated at six million, which is about the same
as at the end of the 15th century, according to some estimates.
In what is now Brazil, the indigenous population declined from a
pre-Columbian high of an estimated four million to some 300,000.
While it is difficult to determine exactly how many Natives lived in North America before Columbus, estimates range from a low of 2.1 million to 7 million people to a high of 18 million.
The aboriginal population of Canada during the late 15th century is estimated to have been between 200,000 and two million, with a figure of 500,000 currently accepted by Canada's Royal Commission on Aboriginal Health. Repeated outbreaks of Old World infectious diseases such as influenza, measles and smallpox
(to which they had no natural immunity), were the main cause of
depopulation. This combined with other factors such as dispossession
from European/Canadian settlements and numerous violent conflicts resulted in a forty- to eighty-percent aboriginal population decrease after contact. For example, during the late 1630s, smallpox killed over half of the Wyandot (Huron), who controlled most of the early North American fur trade in what became Canada. They were reduced to fewer than 10,000 people.
Historian David Henige
has argued that many population figures are the result of arbitrary
formulas selectively applied to numbers from unreliable historical
sources. He believes this is a weakness unrecognized by several
contributors to the field, and insists there is not sufficient evidence
to produce population numbers that have any real meaning. He
characterizes the modern trend of high estimates as "pseudo-scientific
number-crunching." Henige does not advocate a low population estimate,
but argues that the scanty and unreliable nature of the evidence renders
broad estimates inevitably suspect, saying "high counters" (as he calls
them) have been particularly flagrant in their misuse of sources.
Many population studies acknowledge the inherent difficulties in
producing reliable statistics, given the scarcity of hard data.
The population debate has often had ideological underpinnings. Low estimates were sometimes reflective of European notions of cultural and racial superiority. Historian Francis Jennings
argued, "Scholarly wisdom long held that Indians were so inferior in
mind and works that they could not possibly have created or sustained
large populations."
The indigenous population of the Americas in 1492 was not
necessarily at a high point and may actually have been in decline in
some areas. Indigenous populations in most areas of the Americas reached
a low point by the early 20th century. In most cases, populations have
since begun to climb.
Pre-Columbian Americas
Genetic diversity and population structure in the American land mass using DNA micro-satellite markers (genotype) sampled from North, Central, and South America have been analyzed against similar data available from other indigenous populations worldwide. The Amerindian populations show a lower genetic diversity than populations from other continental regions. Observed is both a decreasing genetic diversity as geographic distance from the Bering Strait occurs and a decreasing genetic similarity to Siberian populations from Alaska (genetic entry point).
Also observed is evidence of a higher level of diversity and lower
level of population structure in western South America compared to
eastern South America. A relative lack of differentiation between Mesoamerican and Andean populations is a scenario that implies coastal routes were easier than inland routes for migrating peoples (Paleo-Indians) to traverse.
The overall pattern that is emerging suggests that the Americas were
recently colonized by a small number of individuals (effective size of
about 70-250), and then they grew by a factor of 10 over 800 – 1000
years. The data also show that there have been genetic exchanges between Asia, the Arctic and Greenland since the initial peopling of the Americas. A new study in early 2018 suggests that the effective population size of the original founding population of Native Americans was about 250 people.
Depopulation from disease
Sixteenth-century Aztec drawings of victims of smallpox (above) and measles (below)
Graph demonstrating the population collapse in Central Mexico brought on by successive epidemics in the early colonial period.
According to Noble David Cook, a community of scholars has recently,
albeit slowly, "been quietly accumulating piece by piece data on early
epidemics in the Americas and their relation to the subjugation of
native peoples." They now believe that widespread epidemic disease, to
which the natives had no prior exposure or resistance, was the primary
cause of the massive population decline of the Native Americans.
Earlier explanations for the population decline of the American natives
include the European immigrants' accounts of the brutal practices of
the Spanish conquistadores, as recorded by the Spaniards themselves. This was applied through the encomienda,
which was a system ostensibly set up to protect people from warring
tribes as well as to teach them the Spanish language and the Catholic religion, but in practice was tantamount to serfdom and slavery. The most notable account was that of the DominicanfriarBartolomé de las Casas, whose writings vividly depict Spanish atrocities committed in particular against the Taínos. It took five years for the Taíno rebellion to be quelled by both the Real Audiencia—through diplomatic sabotage, and through the Indian auxiliaries fighting with the Spanish. After Emperor Charles V
personally eradicated the notion of the encomienda system as a use for
slave labour, there were not enough Spanish to have caused such a large
population decline. The second European explanation was a perceived divine approval, in which God removed the natives as part of His "divine plan" to make way for a new Christian
civilization. Many Native Americans viewed their troubles in terms of
religious or supernatural causes within their own belief systems.
Soon after Europeans and enslaved Africans arrived in the New
World, bringing with them the infectious diseases of Europe and Africa,
observers noted immense numbers of indigenous Americans began to die
from these diseases. One reason this death toll was overlooked is that
once introduced, the diseases raced ahead of European immigration in
many areas. The disease killed a sizable portion of the populations
before European written records were made. After the epidemics had
already killed massive numbers of natives, many newer European
immigrants assumed that there had always been relatively few indigenous
peoples. The scope of the epidemics over the years was tremendous,
killing millions of people—possibly in excess of 90% of the population
in the hardest-hit areas—and creating one of "the greatest human
catastrophe in history, far exceeding even the disaster of the Black Death of medieval Europe", which had killed up to one-third of the people in Europe and Asia between 1347 and 1351.
This transfer of disease between the Old and New Worlds was later studied as part of what has been labeled the "Columbian Exchange".
The epidemics had very different effects in different regions of
the Americas. The most vulnerable groups were those with a relatively
small population and few built-up immunities. Many island-based groups
were annihilated. The Caribs and Arawaks of the Caribbean nearly ceased to exist, as did the Beothuks of Newfoundland. While disease raged swiftly through the densely populated empires of Mesoamerica, the more scattered populations of North America saw a slower spread.
The colonization of the Americas killed so many people it resulted in climate change and temporary global cooling, according to scientists from University College London.
According to one of the researchers, UCL Geography Professor Mark
Maslin, the large death toll also boosted the economies of Europe: "the
depopulation of the Americas may have inadvertently allowed the
Europeans to dominate the world. It also allowed for the Industrial
Revolution and for Europeans to continue that domination."
Historian Andrés Reséndez of University of California, Davis
asserts that evidence suggests "slavery has emerged as major killer" of
the indigenous populations of the Caribbean between 1492 and 1550
rather than diseases such as smallpox, influenza and malaria. He posits that unlike the populations of Europe who rebounded following the Black Death,
no such rebound occurred for the indigenous populations of the
Americas. He concludes that, even though the Spanish were aware of
deadly diseases such as smallpox, there is no mention of them in the New
World until 1519, meaning perhaps they didn't spread as fast as
initially believed, and that unlike Europeans, the indigenous
populations were subjected to brutal forced labor in gold and silver
mines on a massive scale. Anthropologist Jason Hickel of the London School of Economics estimates that a third of Arawak workers died every six months from lethal forced labor in these mines.
Historian David Stannard
says that by "focusing almost entirely on disease . . . contemporary
authors increasingly have created the impression that the eradication of
those tens of millions of people was inadvertent - a sad, but both
inevitable and "unintended consequence" of human migration and
progress," and asserts that their destruction "was neither inadvertent
not inevitable," but the result of microbial pestilence and purposeful
genocide working in tandem.
Virulence and mortality
Viral and bacterial
diseases that kill victims before the illnesses spread to others tend
to flare up and then die out. A more resilient disease would establish
an equilibrium; if its victims lived beyond infection, the disease would spread further. The evolutionary process selects against quick lethality, with the most immediately fatal diseases being the most short-lived.
A similar evolutionary pressure acts upon victim populations, as
those lacking genetic resistance to common diseases die and do not leave
descendants, whereas those who are resistant procreate and pass
resistant genes to their offspring. For example, in the first fifty
years of the sixteenth century, an unusually strong strain of syphilis
killed a high proportion of infected Europeans within a few months;
over time, however, the disease has become much less virulent.
Thus both infectious diseases and populations tend to evolve
towards an equilibrium in which the common diseases are non-symptomatic,
mild or manageably chronic.
When a population that has been relatively isolated is exposed to new
diseases, it has no resistance to the new diseases (the population is
"biologically naive"). These people die at a much higher rate, resulting
in what is known as a "virgin soil" epidemic.
Before the European arrival, the Americas had been isolated from the
Eurasian-African landmass. The peoples of the Old World had had
thousands of years for their populations to accommodate to their common
diseases.
The fact that all members of an immunologically naive population
are exposed to a new disease simultaneously increases the fatalities.
In populations where the disease is endemic, generations of individuals
acquired immunity; most adults had exposure to the disease at a young
age. Because they were resistant to reinfection, they are able to care
for individuals who caught the disease for the first time, including the
next generation of children. With proper care, many of these "childhood diseases"
are often survivable. In a naive population, all age groups are
affected at once, leaving few or no healthy caregivers to nurse the
sick. With no resistant individuals healthy enough to tend to the ill, a
disease may have higher fatalities.
The natives of the Americas were faced with several new diseases
at once creating a situation where some who successfully resisted one
disease might die from another. Multiple simultaneous infections (e.g.,
smallpox and typhus at the same time) or in close succession (e.g.,
smallpox in an individual who was still weak from a recent bout of
typhus) are more deadly than just the sum of the individual diseases. In
this scenario, death rates can also be elevated by combinations of new
and familiar diseases: smallpox in combination with American strains of yaws, for example.
Other contributing factors:
Native American medical treatments such as sweat baths and cold water immersion (practiced in some areas) weakened some patients and probably increased mortality rates.
Europeans brought many diseases with them because they had many more domesticated animals than the Native Americans. Domestication
usually means close and frequent contact between animals and people,
which allows diseases of domestic animals to migrate into the human
population when the necessary mutations occur.
The Eurasian landmass extends many thousands of miles along an
east-west axis. Climate zones also extend for thousands of miles, which
facilitated the spread of agriculture, domestication of animals, and the
diseases associated with domestication. The Americas extend mainly
north and south, which, according to the environmental determinist
theory popularized by Jared Diamond in Guns, Germs, and Steel, meant that it was much harder for cultivated plant species, domesticated animals, and diseases to migrate.
Biological warfare
When
Old World diseases were first carried to the Americas at the end of the
fifteenth century, they spread throughout the southern and northern
hemispheres, leaving the indigenous populations in near ruins.
No evidence has been discovered that the earliest Spanish colonists
and missionaries deliberately attempted to infect the American natives,
and some effort was actually made to limit the devastating effects of
disease before it killed off what remained of their forced slave labor
under their encomienda system.
The cattle introduced by the Spanish contaminated various water
reserves which Native Americans dug in the fields to accumulate
rainwater. In response, the Franciscans and Dominicans created public fountains and aqueducts to guarantee access to drinking water. But when the Franciscans lost their privileges in 1572, many of these fountains were no longer guarded and so deliberate well poisoning may have happened.
Although no proof of such poisoning has been found, some historians
believe the decrease of the population correlates with the end of
religious orders' control of the water.
In the centuries that followed, accusations and discussions of
biological warfare were common. Well-documented accounts of incidents
involving both threats and acts of deliberate infection are very rare,
but may have occurred more frequently than scholars have previously
acknowledged.
Many of the instances likely went unreported, and it is possible that
documents relating to such acts were deliberately destroyed, or sanitized.
By the middle of the 18th century, colonists had the knowledge and
technology to attempt biological warfare with the smallpox virus. They
well understood the concept of quarantine, and that contact with the
sick could infect the healthy with smallpox, and those who survived the
illness would not be infected again. Whether the threats were carried
out, or how effective individual attempts were, is uncertain.
One such threat was delivered by fur trader James McDougall,
who is quoted as saying to a gathering of local chiefs, "You know the
smallpox. Listen: I am the smallpox chief. In this bottle I have it
confined. All I have to do is to pull the cork, send it forth among you,
and you are dead men. But this is for my enemies and not my friends." Likewise, another fur trader threatened Pawnee Indians that if they didn't agree to certain conditions, "he would let the smallpox out of a bottle and destroy them." The Reverend Isaac McCoy was quoted in his History of Baptist Indian Missions
as saying that the white men had deliberately spread smallpox among the
Indians of the southwest, including the Pawnee tribe, and the havoc it
made was reported to General Clark and the Secretary of War. Artist and writer George Catlin
observed that Native Americans were also suspicious of vaccination,
"They see white men urging the operation so earnestly they decide that
it must be some new mode or trick of the pale face by which they hope to
gain some new advantage over them." So great was the distrust of the settlers that the Mandan chief Four Bears denounced the white man, whom he had previously treated as brothers, for deliberately bringing the disease to his people.
During the Seven Years' War, British militia took blankets from their smallpox hospital and gave them as gifts to two neutral Lenape
Indian dignitaries during a peace settlement negotiation, according to
the entry in the Captain's ledger, "To convey the Smallpox to the
Indians".
In the following weeks, the high commander of the British forces in
North America conspired with his Colonel to "Extirpate this Execreble
Race" of Native Americans, writing, "Could it not be contrived to send
the small pox among the disaffected tribes of Indians? We must on this
occasion use every stratagem in our power to reduce them." His Colonel
agreed to try. Most scholars have asserted that the 1837 Great Plains smallpox epidemic was "started among the tribes of the upper Missouri River by failure to quarantine steamboats on the river", and Captain Pratt of the St. Peter
"was guilty of contributing to the deaths of thousands of innocent
people. The law calls his offense criminal negligence. Yet in light of
all the deaths, the almost complete annihilation of the Mandans, and the
terrible suffering the region endured, the label criminal negligence is
benign, hardly befitting an action that had such horrendous
consequences."
However, some sources attribute the 1836–40 epidemic to the deliberate
communication of smallpox to Native Americans, with historian Ann F.
Ramenofsky writing, "Variola Major can be transmitted through
contaminated articles such as clothing or blankets. In the nineteenth
century, the U. S. Army sent contaminated blankets to Native Americans,
especially Plains groups, to control the Indian problem."
Well into the 20th century, deliberate infection attacks continued as
Brazilian settlers and miners transported infections intentionally to
the native groups whose lands they coveted."
Vaccination
After Edward Jenner's 1796 demonstration that the smallpox vaccination
worked, the technique became better known and smallpox became less
deadly in the United States and elsewhere. Many colonists and natives
were vaccinated, although, in some cases, officials tried to vaccinate
natives only to discover that the disease was too widespread to stop. At
other times, trade demands led to broken quarantines. In other cases,
natives refused vaccination because of suspicion of whites. The first
international healthcare expedition in history was the Balmis expedition which had the aim of vaccinating indigenous peoples against smallpox all along the Spanish Empire in 1803. In 1831, government officials vaccinated the Yankton Sioux at Sioux Agency. The Santee Sioux refused vaccination and many died.
Depopulation from European Conquest
War and violence
Storming of the Teocalli by Cortez and His Troops by Emanuel Leutze
While epidemic disease was a leading factor of the population decline
of the American indigenous peoples after 1492, there were other
contributing factors, all of them related to European contact and
colonization. One of these factors was warfare. According to demographer
Russell Thornton, although many lives were lost in wars over the
centuries, and war sometimes contributed to the near extinction of
certain tribes, warfare and death by other violent means was a
comparatively minor cause of overall native population decline.
From the U.S. Bureau of the Census in 1894: "The Indian wars
under the government of the United States have been more than 40 in
number [Over the previous 100 years]. They have cost the lives of about
19,000 white men, women and children, including those killed in
individual combats, and the lives of about 30,000 Indians. The actual
number of killed and wounded Indians must be very much higher than the
given... Fifty percent additional would be a safe estimate..."
There is some disagreement among scholars about how widespread warfare was in pre-Columbian America, but there is general agreement that war became deadlier after the arrival of the Europeans and their firearms. The South or Central American infrastructure allowed for thousands of European conquistadors and tens of thousands of their Indian auxiliaries to attack the dominant indigenous civilization. Empires such as the Incas
depended on a highly centralized administration for the distribution of
resources. Disruption caused by the war and the colonization hampered
the traditional economy, and possibly led to shortages of food and
materials. The Arauco War, Chichimeca War, Red Cloud's War, Seminole Wars, War of 1812, Pontiac's Rebellion, Beaver Wars, French-Indian War, American Civil War, American Revolution, Modoc War, Oka Crisis, Battle of Cut Knife, all represented either pyrrhic victories by colonial forces, outright defeat, military stalemates, or further alliance-politics.
Across the western hemisphere, war with various Native American
civilizations constituted alliances based out of both necessity or
economic prosperity and, resulted in mass-scale intertribal warfare.
European colonization in the North American continent also contributed
to a number of wars between Native Americans, who fought over which of
them should have first access to new technology and weaponry—like in the
Beaver Wars.
Exploitation
Some Spaniards objected to the encomienda system, notably Bartolomé de las Casas, who insisted that the Indians were humans with souls and rights. Due to many revolts and military encounters, Emperor Charles V
helped relieve the strain on both the Indian laborers and the Spanish
vanguards probing the Caribana for military and diplomatic purposes. Later on New Laws
were promulgated in Spain in 1542 to protect isolated natives, but the
abuses in the Americas were never entirely or permanently abolished. The
Spanish also employed the pre-Columbian draft system called the mita, and treated their subjects as something between slaves and serfs.
Serfs stayed to work the land; slaves were exported to the mines, where
large numbers of them died. In other areas the Spaniards replaced the
ruling Aztecs and Incas and divided the conquered lands among themselves
ruling as the new feudal lords with often, but unsuccessful lobbying to the viceroys of the Spanish crown to pay Tlaxcalan war demnities. The infamous Bandeirantes from São Paulo, adventurers mostly of mixed Portuguese and native ancestry, penetrated steadily westward in their search for Indian slaves. Serfdom existed as such in parts of Latin America well into the 19th century, past independence.
Massacres
Friar Bartolomé de las Casas
and Antonius Flávio Chesta (Tony Chesta) and other dissenting Spaniards
from the colonial period described the manner in which the natives were
treated by colonials. This has helped to create an image of the Spanish
conquistadores as cruel in the extreme.
Great revenues were drawn from Hispaniola so the advent of losing manpower didn't benefit the Spanish crown. At best, the reinforcement of vanguards sent by the Council of the Indies
to explore the Caribana country and gather information on alliances or
hostilities was the main goal of the local viceroys and their adelantados. Although mass killings and atrocities
were not a significant factor in native depopulation, no mainstream
scholar dismisses the sometimes humiliating circumstances now believed
to be precipitated by civil disorder as well as Spanish cruelty.
While some California
tribes were settled on reservations, others were hunted down and
massacred by 19th century American settlers. It is estimated that at
least 9,400 to 16,000 California Indians were killed by non-Indians,
mostly occurring in more than 370 massacres (defined as the "intentional
killing of five or more disarmed combatants or largely unarmed
noncombatants, including women, children, and prisoners, whether in the
context of a battle or otherwise").
Displacement and disruption
The populations of many Native American peoples were reduced by the common practice of intermarrying with Europeans.
Although many Indian cultures that once thrived are extinct today,
their descendants exist today in some of the bloodlines of the current
inhabitants of the Americas.
Formal apology from the United States government
On 8 September 2000, the head of the United States Bureau of Indian Affairs (BIA) formally apologized for the agency's participation in the "ethnic cleansing" of Western tribes.
In a speech before representatives of Native American peoples in June, 2019, California governor Gavin Newsom apologized for the California Genocide.
Newsom said, "That’s what it was, a genocide. No other way to describe
it. And that’s the way it needs to be described in the history books."
