Phased array

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Phased_array 

Animation showing how a phased array works. It consists of an array of antenna elements (A) powered by a transmitter (TX). The feed current for each element passes through a phase shifter (φ) controlled by a computer (C). The moving red lines show the wavefronts of the radio waves emitted by each element. The individual wavefronts are spherical, but they combine (superpose) in front of the antenna to create a plane wave, a beam of radio waves travelling in a specific direction. The phase shifters delay the radio waves progressively going up the line so each antenna emits its wavefront later than the one below it. This causes the resulting plane wave to be directed at an angle θ to the antenna's axis. By changing the phase shifts the computer can instantly change the angle θ of the beam. Most phased arrays have two-dimensional arrays of antennas instead of the linear array shown here, and the beam can be steered in two dimensions. The velocity of the radio waves shown have been slowed down in this diagram.

 

Animation showing the radiation pattern of a phased array of 15 antenna elements spaced a quarter wavelength apart as the phase difference between adjacent antennas is swept between −120 and 120 degrees. The dark area is the beam or main lobe, while the light lines fanning out around it are sidelobes.

In antenna theory, a phased array usually means an electronically scanned array, a computer-controlled array of antennas which creates a beam of radio waves that can be electronically steered to point in different directions without moving the antennas.

In a simple array antenna, the radio frequency current from the transmitter is fed to multiple individual antenna elements with the proper phase relationship so that the radio waves from the separate elements combine (superpose) to form beams, to increase power radiated in desired directions and suppress radiation in undesired directions. In a phased array, the power from the transmitter is fed to the radiating elements through devices called phase shifters, controlled by a computer system, which can alter the phase or signal delay electronically, thus steering the beam of radio waves to a different direction. Since the size of an antenna array must extend many wavelengths to achieve the high gain needed for narrow beamwidth, phased arrays are mainly practical at the high frequency end of the radio spectrum, in the UHF and microwave bands, in which the operating wavelengths are conveniently small.

Phased arrays were originally conceived for use in military radar systems, to steer a beam of radio waves quickly across the sky to detect planes and missiles. These systems are now widely used and have spread to civilian applications such as 5G MIMO for cell phones. The phased array principle is also used in acoustics, and phased arrays of acoustic transducers are used in medical ultrasound imaging scanners (phased array ultrasonics), oil and gas prospecting (reflection seismology), and military sonar systems.

The term "phased array" is also used to a lesser extent for unsteered array antennas in which the phase of the feed power and thus the radiation pattern of the antenna array is fixed. For example, AM broadcast radio antennas consisting of multiple mast radiators fed so as to create a specific radiation pattern are also called "phased arrays".

Types

Phased arrays take multiple forms. However, the four most common are the passive electronically scanned array (PESA), active electronically scanned array (AESA), hybrid beam forming phased array, and digital beam forming (DBF) array.

A passive phased array or passive electronically scanned array (PESA) is a phased array in which the antenna elements are connected to a single transmitter and/or receiver, as shown in the first animation at top. PESAs are the most common type of phased array. Generally speaking, a PESA uses one receiver/exciter for the entire array.

An active phased array or active electronically scanned array (AESA) is a phased array in which each antenna element has an analog transmitter/receiver (T/R) module which creates the phase shifting required to electronically steer the antenna beam. Active arrays are a more advanced, second-generation phased-array technology which are used in military applications; unlike PESAs they can radiate several beams of radio waves at multiple frequencies in different directions simultaneously. However, the number of simultaneous beams is limited by practical reasons of electronic packaging of the beam formers to approximately three simultaneous beams for an AESA. Each beam former has a receiver/exciter connected to it.

A hybrid beam forming phased array can be thought of as a combination of an AESA and a digital beam forming phased array. It uses subarrays that are active phased arrays (for instance, a subarray may be 64, 128 or 256 elements and the number of elements depends upon system requirements). The subarrays are combined to form the full array. Each subarray has its own digital receiver/exciter. This approach allows clusters of simultaneous beams to be created.

A digital beam forming (DBF) phased array has a digital receiver/exciter at each element in the array. The signal at each element is digitized by the receiver/exciter. This means that antenna beams can be formed digitally in a field programmable gate array (FPGA) or the array computer. This approach allows for multiple simultaneous antenna beams to be formed.

A conformal antenna is a phased array in which the individual antennas, instead of being arranged in a flat plane, are mounted on a curved surface. The phase shifters compensate for the different path lengths of the waves due to the antenna elements' varying position on the surface, allowing the array to radiate a plane wave. Conformal antennas are used in aircraft and missiles, to integrate the antenna into the curving surface of the aircraft to reduce aerodynamic drag.

History

Ferdinand Braun's 1905 directional antenna which used the phased array principle, consisting of 3 monopole antennas in an equilateral triangle. A quarter-wave delay in the feedline of one antenna caused the array to radiate in a beam. The delay could be switched manually into any of the 3 feeds, rotating the antenna beam by 120°.

 

US PAVE PAWS active phased array ballistic missile detection radar in Alaska. Completed in 1979, it was one of the first active phased arrays.

 

Closeup of some of the 2677 crossed dipole antenna elements that make up the plane array. This antenna produced a narrow "pencil" beam only 2.2° wide.

 

BMEWS & PAVE PAWS Radars

 

Mammut phased array radar World War II

Phased array transmission was originally shown in 1905 by Nobel laureate Karl Ferdinand Braun who demonstrated enhanced transmission of radio waves in one direction. During World War II, Nobel laureate Luis Alvarez used phased array transmission in a rapidly steerable radar system for "ground-controlled approach", a system to aid in the landing of aircraft. At the same time, the GEMA in Germany built the Mammut 1. It was later adapted for radio astronomy leading to Nobel Prizes for Physics for Antony Hewish and Martin Ryle after several large phased arrays were developed at the University of Cambridge Interplanetary Scintillation Array. This design is also used for radar, and is generalized in interferometric radio antennas.

In 2004, Caltech researchers demonstrated the first integrated silicon-based phased array receiver at 24 GHz with 8 elements. This was followed by their demonstration of a CMOS 24 GHz phased array transmitter in 2005 and a fully integrated 77 GHz phased array transceiver with integrated antennas in 2006 by the Caltech team. In 2007, DARPA researchers announced a 16 element phased array radar antenna which was also integrated with all the necessary circuits on a single silicon chip and operated at 30–50 GHz.

The relative amplitudes of—and constructive and destructive interference effects among—the signals radiated by the individual antennas determine the effective radiation pattern of the array. A phased array may be used to point a fixed radiation pattern, or to scan rapidly in azimuth or elevation. Simultaneous electrical scanning in both azimuth and elevation was first demonstrated in a phased array antenna at Hughes Aircraft Company, California in 1957.

Applications

Broadcasting

In broadcast engineering, the term 'phased array' has a meaning different from its normal meaning, it means an ordinary array antenna, an array of multiple mast radiators designed to radiate a directional radiation pattern, as opposed to a single mast which radiates an omnidirectional pattern. Broadcast phased arrays have fixed radiation patterns and are not 'steered' during operation as are other phased arrays.

Phased arrays are used by many AM broadcast radio stations to enhance signal strength and therefore coverage in the city of license, while minimizing interference to other areas. Due to the differences between daytime and nighttime ionospheric propagation at mediumwave frequencies, it is common for AM broadcast stations to change between day (groundwave) and night (skywave) radiation patterns by switching the phase and power levels supplied to the individual antenna elements (mast radiators) daily at sunrise and sunset. For shortwave broadcasts many stations use arrays of horizontal dipoles. A common arrangement uses 16 dipoles in a 4×4 array. Usually this is in front of a wire grid reflector. The phasing is often switchable to allow beam steering in azimuth and sometimes elevation.

More modest phased array longwire antenna systems may be employed by private radio enthusiasts to receive longwave, mediumwave (AM) and shortwave radio broadcasts from great distances.

On VHF, phased arrays are used extensively for FM broadcasting. These greatly increase the antenna gain, magnifying the emitted RF energy toward the horizon, which in turn greatly increases a station's broadcast range. In these situations, the distance to each element from the transmitter is identical, or is one (or other integer) wavelength apart. Phasing the array such that the lower elements are slightly delayed (by making the distance to them longer) causes a downward beam tilt, which is very useful if the antenna is quite high on a radio tower.

Other phasing adjustments can increase the downward radiation in the far field without tilting the main lobe, creating null fill to compensate for extremely high mountaintop locations, or decrease it in the near field, to prevent excessive exposure to those workers or even nearby homeowners on the ground. The latter effect is also achieved by half-wave spacing – inserting additional elements halfway between existing elements with full-wave spacing. This phasing achieves roughly the same horizontal gain as the full-wave spacing; that is, a five-element full-wave-spaced array equals a nine- or ten-element half-wave-spaced array.

Radar

Phased array radar systems are also used by warships of many navies. Because of the rapidity with which the beam can be steered, phased array radars allow a warship to use one radar system for surface detection and tracking (finding ships), air detection and tracking (finding aircraft and missiles) and missile uplink capabilities. Before using these systems, each surface-to-air missile in flight required a dedicated fire-control radar, which meant that radar-guided weapons could only engage a small number of simultaneous targets. Phased array systems can be used to control missiles during the mid-course phase of the missile's flight. During the terminal portion of the flight, continuous-wave fire control directors provide the final guidance to the target. Because the antenna pattern is electronically steered, phased array systems can direct radar beams fast enough to maintain a fire control quality track on many targets simultaneously while also controlling several in-flight missiles.

Active Phased Array Radar mounted on top of Sachsen-class frigate F220 Hamburg's superstructure of the German Navy

The AN/SPY-1 phased array radar, part of the Aegis Combat System deployed on modern U.S. cruisers and destroyers, "is able to perform search, track and missile guidance functions simultaneously with a capability of over 100 targets." Likewise, the Thales Herakles phased array multi-function radar used in service with France and Singapore has a track capacity of 200 targets and is able to achieve automatic target detection, confirmation and track initiation in a single scan, while simultaneously providing mid-course guidance updates to the MBDA Aster missiles launched from the ship. The German Navy and the Royal Dutch Navy have developed the Active Phased Array Radar System (APAR). The MIM-104 Patriot and other ground-based antiaircraft systems use phased array radar for similar benefits.

Phased arrays are used in naval sonar, in active (transmit and receive) and passive (receive only) and hull-mounted and towed array sonar.

See also: SAMPSON, Active Phased Array Radar, SMART-L, Active Electronically Scanned Array, Aegis combat system, and AN/SPY-1

Space probe communication

The MESSENGER spacecraft was a space probe mission to the planet Mercury (2011–2015). This was the first deep-space mission to use a phased-array antenna for communications. The radiating elements are circularly-polarized, slotted waveguides. The antenna, which uses the X band, used 26 radiative elements and can gracefully degrade.

Weather research usage

AN/SPY-1A radar installation at National Severe Storms Laboratory, Norman, Oklahoma. The enclosing radome provides weather protection.

The National Severe Storms Laboratory has been using a SPY-1A phased array antenna, provided by the US Navy, for weather research at its Norman, Oklahoma facility since April 23, 2003. It is hoped that research will lead to a better understanding of thunderstorms and tornadoes, eventually leading to increased warning times and enhanced prediction of tornadoes. Current project participants include the National Severe Storms Laboratory and National Weather Service Radar Operations Center, Lockheed Martin, United States Navy, University of Oklahoma School of Meteorology, School of Electrical and Computer Engineering, and Atmospheric Radar Research Center, Oklahoma State Regents for Higher Education, the Federal Aviation Administration, and Basic Commerce and Industries. The project includes research and development, future technology transfer and potential deployment of the system throughout the United States. It is expected to take 10 to 15 years to complete and initial construction was approximately $25 million. A team from Japan's RIKEN Advanced Institute for Computational Science (AICS) has begun experimental work on using phased-array radar with a new algorithm for instant weather forecasts.

Optics

Main article: Phased-array optics

Within the visible or infrared spectrum of electromagnetic waves it is possible to construct optical phased arrays. They are used in wavelength multiplexers and filters for telecommunication purposes, laser beam steering, and holography. Synthetic array heterodyne detection is an efficient method for multiplexing an entire phased array onto a single element photodetector. The dynamic beam forming in an optical phased array transmitter can be used to electronically raster or vector scan images without using lenses or mechanically moving parts in a lensless projector. Optical phased array receivers have been demonstrated to be able to act as lensless cameras by selectively looking at different directions.

Satellite broadband internet transceivers

Starlink is a low Earth orbit satellite constellation that is under construction as of 2021. It is designed to provide broadband internet connectivity to consumers; the user terminals of the system will use phased array antennas.

Radio-frequency identification (RFID)

By 2014, phased array antennas were integrated into RFID systems to increase the area of coverage of a single system by 100% to 76,200 m² (820,000 sq ft) while still using traditional passive UHF tags.

Human-machine interfaces (HMI)

A phased array of acoustic transducers, denominated airborne ultrasound tactile display (AUTD), was developed in 2008 at the University of Tokyo's Shinoda Lab to induce tactile feedback. This system was demonstrated to enable a user to interactively manipulate virtual holographic objects.

Radio Astronomy

Phased Array Feeds (PAF) have recently been used at the focus of radio telescopes to provide many beams, giving the radio telescope a very wide field of view. Two examples are the ASKAP telescope in Australia and the Apertif upgrade to the Westerbork Synthesis Radio Telescope in The Netherlands.

Mathematical perspective and formulas

The radiation pattern of a phased array in polar coordinate system.

Mathematically a phased array is an example of N-slit diffraction, in which the radiation field at the receiving point is the result of the coherent addition of N point sources in a line. Since each individual antenna acts as a slit, emitting radio waves, their diffraction pattern can be calculated by adding the phase shift φ to the fringing term.

We will begin from the N-slit diffraction pattern derived on the diffraction formalism page, with ${\displaystyle N}$ slits of equal size ${\displaystyle a}$ and spacing ${\displaystyle d}$.

${\displaystyle \psi =\psi _{0}\,{\frac {\sin \left({\frac {\pi a}{\lambda }}\sin \theta \right)}{{\frac {\pi a}{\lambda }}\sin \theta }}\,{\frac {\sin \left({\frac {N}{2}}kd\sin \theta \right)}{\sin \left({\frac {kd}{2}}\sin \theta \right)}}}$

Now, adding a φ term to the ${\textstyle kd\sin \theta \,}$ fringe effect in the second term yields:

${\displaystyle \psi =\psi _{0}\,{\frac {\sin \left({\frac {\pi a}{\lambda }}\sin \theta \right)}{{\frac {\pi a}{\lambda }}\sin \theta }}\,{\frac {\sin \left({\frac {N}{2}}\left({\frac {2\pi d}{\lambda }}\sin \theta +\phi \right)\right)}{\sin \left({\frac {\pi d}{\lambda }}\sin \theta +{\frac {\phi }{2}}\right)}}}$

Taking the square of the wave function gives us the intensity of the wave.

${\displaystyle {\begin{aligned}I&=I_{0}\left({\frac {\sin \left({\frac {\pi a}{\lambda }}\sin \theta \right)}{{\frac {\pi a}{\lambda }}\sin \theta }}\right)^{2}\left({\frac {\sin \left({\frac {N}{2}}\left({\frac {2\pi d}{\lambda }}\sin \theta +\phi \right)\right)}{\sin \left({\frac {\pi d}{\lambda }}\sin \theta +{\frac {\phi }{2}}\right)}}\right)^{2}\\I&=I_{0}\left({\frac {\sin \left({\frac {\pi a}{\lambda }}\sin \theta \right)}{{\frac {\pi a}{\lambda }}\sin \theta }}\right)^{2}\left({\frac {\sin \left({\frac {\pi }{\lambda }}Nd\sin \theta +{\frac {N}{2}}\phi \right)}{\sin \left({\frac {\pi d}{\lambda }}\sin \theta +{\frac {\phi }{2}}\right)}}\right)^{2}\end{aligned}}}$

Now space the emitters a distance ${\textstyle d={\frac {\lambda }{4}}}$ apart. This distance is chosen for simplicity of calculation but can be adjusted as any scalar fraction of the wavelength.

${\displaystyle I=I_{0}{{\left({\frac {\sin \left({\frac {\pi a}{\lambda }}\sin \theta \right)}{{\frac {\pi a}{\lambda }}\sin \theta }}\right)}^{2}}{{\left({\frac {\sin \left({\frac {\pi }{4}}N\sin \theta +{\frac {N}{2}}\phi \right)}{\sin \left({\frac {\pi }{4}}\sin \theta +{\frac {\phi }{2}}\right)}}\right)}^{2}}}$

As sine achieves its maximum at ${\textstyle {\frac {\pi }{2}}}$, we set the numerator of the second term = 1.

${\displaystyle {\begin{aligned}{\frac {\pi }{4}}N\sin \theta +{\frac {N}{2}}\phi &={\frac {\pi }{2}}\\\sin \theta &=\left({\frac {\pi }{2}}-{\frac {N}{2}}\phi \right){\frac {4}{N\pi }}\\\sin \theta &={\frac {2}{N}}-{\frac {2\phi }{\pi }}\end{aligned}}}$

Thus as N gets large, the term will be dominated by the ${\displaystyle {\begin{matrix}{\frac {2\phi }{\pi }}\end{matrix}}}$ term. As sine can oscillate between −1 and 1, we can see that setting ${\displaystyle \phi =-{\begin{matrix}{\frac {\pi }{2}}\end{matrix}}}$ will send the maximum energy on an angle given by

${\displaystyle \theta =\sin ^{-1}1={\frac {\pi }{2}}=90^{\circ }}$

Additionally, we can see that if we wish to adjust the angle at which the maximum energy is emitted, we need only to adjust the phase shift φ between successive antennas. Indeed, the phase shift corresponds to the negative angle of maximum signal.

A similar calculation will show that the denominator is minimized by the same factor.

Different types of phased arrays

Main article: Beamforming

There are two main types of beamformers. These are time domain beamformers and frequency domain beamformers. From a theoretical point of view, both are in principle the same operation, with just a Fourier transform allowing conversion from one to the other type.

A graduated attenuation window is sometimes applied across the face of the array to improve side-lobe suppression performance, in addition to the phase shift.

Time domain beamformer works by introducing time delays. The basic operation is called "delay and sum". It delays the incoming signal from each array element by a certain amount of time, and then adds them together. A Butler matrix allows several beams to be formed simultaneously, or one beam to be scanned through an arc. The most common kind of time domain beam former is serpentine waveguide. Active phased array designs use individual delay lines that are switched on and off. Yttrium iron garnet phase shifters vary the phase delay using the strength of a magnetic field.

There are two different types of frequency domain beamformers.

The first type separates the different frequency components that are present in the received signal into multiple frequency bins (using either a Discrete Fourier transform (DFT) or a filterbank). When different delay and sum beamformers are applied to each frequency bin, the result is that the main lobe simultaneously points in multiple different directions at each of the different frequencies. This can be an advantage for communication links, and is used with the SPS-48 radar.

The other type of frequency domain beamformer makes use of Spatial Frequency. Discrete samples are taken from each of the individual array elements. The samples are processed using a DFT. The DFT introduces multiple different discrete phase shifts during processing. The outputs of the DFT are individual channels that correspond with evenly spaced beams formed simultaneously. A 1-dimensional DFT produces a fan of different beams. A 2-dimensional DFT produces beams with a pineapple configuration.

These techniques are used to create two kinds of phased array.

• Dynamic – an array of variable phase shifters are used to move the beam
• Fixed – the beam position is stationary with respect to the array face and the whole antenna is moved

There are two further sub-categories that modify the kind of dynamic array or fixed array.

• Active – amplifiers or processors are in each phase shifter element
• Passive – large central amplifier with attenuating phase shifters

Dynamic phased array

Each array element incorporates an adjustable phase shifter that are collectively used to move the beam with respect to the array face.

Dynamic phased array require no physical movement to aim the beam. The beam is moved electronically. This can produce antenna motion fast enough to use a small pencil-beam to simultaneously track multiple targets while searching for new targets using just one radar set (track while search).

As an example, an antenna with a 2 degree beam with a pulse rate of 1 kHz will require approximately 8 seconds to cover an entire hemisphere consisting of 8,000 pointing positions. This configuration provides 12 opportunities to detect a 1,000 m/s (2,200 mph; 3,600 km/h) vehicle over a range of 100 km (62 mi), which is suitable for military applications.

The position of mechanically steered antennas can be predicted, which can be used to create electronic countermeasures that interfere with radar operation. The flexibility resulting from phased array operation allows beams to be aimed at random locations, which eliminates this vulnerability. This is also desirable for military applications.

Fixed phased array

An antenna tower consisting of a fixed phase collinear antenna array with four elements

Fixed phased array antennas are typically used to create an antenna with a more desirable form factor than the conventional parabolic reflector or cassegrain reflector. Fixed phased arrays incorporate fixed phase shifters. For example, most commercial FM Radio and TV antenna towers use a collinear antenna array, which is a fixed phased array of dipole elements.

In radar applications, this kind of phased array is physically moved during the track and scan process. There are two configurations.

• Multiple frequencies with a delay-line
• Multiple adjacent beams

The SPS-48 radar uses multiple transmit frequencies with a serpentine delay line along the left side of the array to produce vertical fan of stacked beams. Each frequency experiences a different phase shift as it propagates down the serpentine delay line, which forms different beams. A filter bank is used to split apart the individual receive beams. The antenna is mechanically rotated.

Semi-active radar homing uses monopulse radar that relies on a fixed phased array to produce multiple adjacent beams that measure angle errors. This form factor is suitable for gimbal mounting in missile seekers.

Active phased array

Active electronically-scanned arrays (AESA) elements incorporate transmit amplification with phase shift in each antenna element (or group of elements). Each element also includes receive pre-amplification. The phase shifter setting is the same for transmit and receive.

Active phased arrays do not require phase reset after the end of the transmit pulse, which is compatible with Doppler radar and pulse-Doppler radar.

Passive phased array

Passive phased arrays typically use large amplifiers that produce all of the microwave transmit signal for the antenna. Phase shifters typically consist of waveguide elements controlled by magnetic field, voltage gradient, or equivalent technology.

The phase shift process used with passive phased arrays typically puts the receive beam and transmit beam into diagonally opposite quadrants. The sign of the phase shift must be inverted after the transmit pulse is finished and before the receive period begins to place the receive beam into the same location as the transmit beam. That requires a phase impulse that degrades sub-clutter visibility performance on Doppler radar and Pulse-Doppler radar. As an example, Yttrium iron garnet phase shifters must be changed after transmit pulse quench and before receiver processing starts to align transmit and receive beams. That impulse introduces FM noise that degrades clutter performance.

Passive phased array design is used in the AEGIS Combat System. for direction-of-arrival estimation.

Substance abuse

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Substance_abuse 

Substance abuse
Other names	Drug abuse, substance use disorder, substance misuse disorder
A tin containing drugs and drug paraphernalia
Specialty	Psychiatry
Complications	Drug overdose
Frequency	27 million
Deaths	307,400 (2015)

A person sniffing an inhalant

Substance abuse, also known as drug abuse, is the use of a drug in amounts or by methods which are harmful to the individual or others. It is a form of substance-related disorder. Differing definitions of drug abuse are used in public health, medical and criminal justice contexts. In some cases, criminal or anti-social behaviour occurs when the person is under the influence of a drug, and long-term personality changes in individuals may also occur. In addition to possible physical, social, and psychological harm, the use of some drugs may also lead to criminal penalties, although these vary widely depending on the local jurisdiction.

Drugs most often associated with this term include: alcohol, amphetamines, barbiturates, benzodiazepines, cannabis, cocaine, hallucinogens, methaqualone, and opioids. The exact cause of substance abuse is not clear, but there are two predominant theories: either a genetic predisposition or a habit learned from others, which, if addiction develops, manifests itself as a chronic debilitating disease.

In 2010 about 5% of people (230 million) used an illicit substance. Of these, 27 million have high-risk drug use—otherwise known as recurrent drug use—causing harm to their health, causing psychological problems, and/or causing social problems that put them at risk of those dangers. In 2015, substance use disorders resulted in 307,400 deaths, up from 165,000 deaths in 1990. Of these, the highest numbers are from alcohol use disorders at 137,500, opioid use disorders at 122,100 deaths, amphetamine use disorders at 12,200 deaths, and cocaine use disorders at 11,100.

Classification

Public health definitions

A drug user receiving an injection of the opiate heroin

Public health practitioners have attempted to look at substance use from a broader perspective than the individual, emphasizing the role of society, culture, and availability. Some health professionals choose to avoid the terms alcohol or drug "abuse" in favor of language considered more objective, such as "substance and alcohol type problems" or "harmful/problematic use" of drugs. The Health Officers Council of British Columbia — in their 2005 policy discussion paper, A Public Health Approach to Drug Control in Canada — has adopted a public health model of psychoactive substance use that challenges the simplistic black-and-white construction of the binary (or complementary) antonyms "use" vs. "abuse". This model explicitly recognizes a spectrum of use, ranging from beneficial use to chronic dependence.

Medical definitions

A 2010 study ranking various illegal and legal drugs based on statements by drug-harm experts. Alcohol was found to be the overall most dangerous drug.

'Drug abuse' is no longer a current medical diagnosis in either of the most used diagnostic tools in the world, the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM), and the World Health Organization's International Classification of Diseases (ICD).

Value judgment

This diagram depicts the correlations among the usage of 18 legal and illegal drugs: alcohol, amphetamines, amyl nitrite, benzodiazepines, cannabis, chocolate, cocaine, caffeine, crack, ecstasy, heroin, ketamine, legal highs, LSD, methadone, magic mushrooms (MMushrooms), nicotine and volatile substance abuse (VSA). Usage is defined as having used the drug at least once during years 2005–2015. The colored links between drugs indicate the correlations with |r|>0.4, where |r| is the absolute value of the Pearson correlation coefficient.

Philip Jenkins suggests that there are two issues with the term "drug abuse". First, what constitutes a "drug" is debatable. For instance, GHB, a naturally occurring substance in the central nervous system is considered a drug, and is illegal in many countries, while nicotine is not officially considered a drug in most countries.

Second, the word "abuse" implies a recognized standard of use for any substance. Drinking an occasional glass of wine is considered acceptable in most Western countries, while drinking several bottles is seen as an abuse. Strict temperance advocates, who may or may not be religiously motivated, would see drinking even one glass as an abuse. Some groups (Mormons, as prescribed in “the Word of Wisdom”) even condemn caffeine use in any quantity. Similarly, adopting the view that any (recreational) use of cannabis or substituted amphetamines constitutes drug abuse implies a decision made that the substance is harmful, even in minute quantities. In the U.S., drugs have been legally classified into five categories, schedule I, II, III, IV, or V in the Controlled Substances Act. The drugs are classified on their deemed potential for abuse. Usage of some drugs is strongly correlated. For example, the consumption of seven illicit drugs (amphetamines, cannabis, cocaine, ecstasy, legal highs, LSD, and magic mushrooms) is correlated and the Pearson correlation coefficient r>0.4 in every pair of them; consumption of cannabis is strongly correlated (r>0.5) with usage of nicotine (tobacco), heroin is correlated with cocaine (r>0.4) and methadone (r>0.45), and is strongly correlated with crack (r>0.5)

Drug misuse

Drug misuse is a term used commonly when prescription medication with sedative, anxiolytic, analgesic, or stimulant properties are used for mood alteration or intoxication ignoring the fact that overdose of such medicines can sometimes have serious adverse effects. It sometimes involves drug diversion from the individual for whom it was prescribed.

Prescription misuse has been defined differently and rather inconsistently based on status of drug prescription, the uses without a prescription, intentional use to achieve intoxicating effects, route of administration, co-ingestion with alcohol, and the presence or absence of dependence symptoms. Chronic use of certain substances leads to a change in the central nervous system known as a 'tolerance' to the medicine such that more of the substance is needed in order to produce desired effects. With some substances, stopping or reducing use can cause withdrawal symptoms to occur, but this is highly dependent on the specific substance in question.

The rate of prescription drug use is fast overtaking illegal drug use in the United States. According to the National Institute of Drug Abuse, 7 million people were taking prescription drugs for nonmedical use in 2010. Among 12th graders, nonmedical prescription drug use is now second only to cannabis. In 2011, "Nearly 1 in 12 high school seniors reported nonmedical use of Vicodin; 1 in 20 reported such use of OxyContin." Both of these drugs contain opioids. A 2017 survey of 12th graders in the United States, found misuse of OxyContin of 2.7 percent, compared to 5.5 percent at its peak in 2005. Misuse of the combination hydrocodone/paracetamol was at its lowest since a peak of 10.5 percent in 2003. This decrease may be related to public health initiatives and decreased availability.

Avenues of obtaining prescription drugs for misuse are varied: sharing between family and friends, illegally buying medications at school or work, and often "doctor shopping" to find multiple physicians to prescribe the same medication, without knowledge of other prescribers.

Increasingly, law enforcement is holding physicians responsible for prescribing controlled substances without fully establishing patient controls, such as a patient "drug contract". Concerned physicians are educating themselves on how to identify medication-seeking behavior in their patients, and are becoming familiar with "red flags" that would alert them to potential prescription drug abuse.

Signs and symptoms

Rational scale to assess the harm of recreational drug use

Drug	Drug class	Physical harm	Dependence liability	Social harm	Avg. harm
Methamphetamine	CNS stimulant	3.00	2.80	2.72	2.92
Heroin	Opioid	2.78	3.00	2.54	2.77
Cocaine	CNS stimulant	2.33	2.39	2.17	2.30
Barbiturates	CNS depressant	2.23	2.01	2.00	2.08
Methadone	Opioid	1.86	2.08	1.87	1.94
Alcohol	CNS depressant	1.40	1.93	2.21	1.85
Ketamine	Dissociative anesthetic	2.00	1.54	1.69	1.74
Benzodiazepines	Benzodiazepine	1.63	1.83	1.65	1.70
Amphetamine	CNS stimulant	1.81	1.67	1.50	1.66
Tobacco	Tobacco	1.24	2.21	1.42	1.62
Buprenorphine	Opioid	1.60	1.64	1.49	1.58
Cannabis	Cannabinoid	0.99	1.51	1.50	1.33
Solvent drugs	Inhalant	1.28	1.01	1.52	1.27
4-MTA	Designer SSRA	1.44	1.30	1.06	1.27
LSD	Psychedelic	1.13	1.23	1.32	1.23
Methylphenidate	CNS stimulant	1.32	1.25	0.97	1.18
Anabolic steroids	Anabolic steroid	1.45	0.88	1.13	1.15
GHB	Neurotransmitter	0.86	1.19	1.30	1.12
Ecstasy	Empathogenic stimulant	1.05	1.13	1.09	1.09
Alkyl nitrites	Inhalant	0.93	0.87	0.97	0.92
Khat	CNS stimulant	0.50	1.04	0.85	0.80

Depending on the actual compound, drug abuse including alcohol may lead to health problems, social problems, morbidity, injuries, unprotected sex, violence, deaths, motor vehicle accidents, homicides, suicides, physical dependence or psychological addiction.

There is a high rate of suicide in alcoholics and other drug abusers. The reasons believed to cause the increased risk of suicide include the long-term abuse of alcohol and other drugs causing physiological distortion of brain chemistry as well as the social isolation. Another factor is the acute intoxicating effects of the drugs may make suicide more likely to occur. Suicide is also very common in adolescent alcohol abusers, with 1 in 4 suicides in adolescents being related to alcohol abuse. In the US, approximately 30% of suicides are related to alcohol abuse. Alcohol abuse is also associated with increased risks of committing criminal offences including child abuse, domestic violence, rapes, burglaries and assaults.

Drug abuse, including alcohol and prescription drugs, can induce symptomatology which resembles mental illness. This can occur both in the intoxicated state and also during withdrawal. In some cases, substance-induced psychiatric disorders can persist long after detoxification, such as prolonged psychosis or depression after amphetamine or cocaine abuse. A protracted withdrawal syndrome can also occur with symptoms persisting for months after cessation of use. Benzodiazepines are the most notable drug for inducing prolonged withdrawal effects with symptoms sometimes persisting for years after cessation of use. Both alcohol, barbiturate as well as benzodiazepine withdrawal can potentially be fatal. Abuse of hallucinogens can trigger delusional and other psychotic phenomena long after cessation of use.

Cannabis may trigger panic attacks during intoxication and with continued use, it may cause a state similar to dysthymia. Researchers have found that daily cannabis use and the use of high-potency cannabis are independently associated with a higher chance of developing schizophrenia and other psychotic disorders.

Severe anxiety and depression are commonly induced by sustained alcohol abuse. Even sustained moderate alcohol use may increase anxiety and depression levels in some individuals. In most cases, these drug-induced psychiatric disorders fade away with prolonged abstinence. Similarly, although substance abuse induces many changes to the brain, there is evidence that many of these alterations are reversed following periods of prolonged abstinence.

Impulsivity

Impulsivity is characterized by actions based on sudden desires, whims, or inclinations rather than careful thought. Individuals with substance abuse have higher levels of impulsivity, and individuals who use multiple drugs tend to be more impulsive. A number of studies using the Iowa gambling task as a measure for impulsive behavior found that drug using populations made more risky choices compared to healthy controls. There is a hypothesis that the loss of impulse control may be due to impaired inhibitory control resulting from drug induced changes that take place in the frontal cortex. The neurodevelopmental and hormonal changes that happen during adolescence may modulate impulse control that could possibly lead to the experimentation with drugs and may lead to the road of addiction. Impulsivity is thought to be a facet trait in the neuroticism personality domain (overindulgence/negative urgency) which is prospectively associated with the development of substance abuse.

Screening and assessment

The screening and assessment process of substance use behavior is important for the diagnosis and treatment of substance use disorders. Screeners is the process of identifying individuals who have or may be at risk for a substance use disorder and are usually brief to administer. Assessments are used to clarify the nature of the substance use behavior to help determine appropriate treatment. Assessments usually require specialized skills, and are longer to administer than screeners.

Given that addiction manifests in structural changes to the brain, it is possible that non-invasive magnetic resonance imaging could help diagnose addiction in the future.

Targeted assessments

There are several different screening tools that have been validated for use with adolescents such as the CRAFFT Screening Test and in adults the CAGE questionnaire. Some recommendations for screening tools for substance misuse in pregnancy include that they take less than 10 minutes, should be used routinely, include an educational component. Tools suitable for pregnant women include i.a. 4Ps, T-ACE, TWEAK, TQDH (Ten-Question Drinking History), and AUDIT.

Treatment

Psychological

From the applied behavior analysis literature, behavioral psychology, and from randomized clinical trials, several evidenced based interventions have emerged: behavioral marital therapy, motivational Interviewing, community reinforcement approach, exposure therapy, contingency management. They help suppress cravings and mental anxiety, improve focus on treatment and new learning behavioral skills, ease withdrawal symptoms and reduce the chances of relapse.

In children and adolescents, cognitive behavioral therapy (CBT) and family therapy currently has the most research evidence for the treatment of substance abuse problems. Well-established studies also include ecological family-based treatment and group CBT. These treatments can be administered in a variety of different formats, each of which has varying levels of research support Research has shown that what makes group CBT most effective is that it promotes the development of social skills, developmentally appropriate emotional regulatory skills and other interpersonal skills. A few integrated treatment models, which combines parts from various types of treatment, have also been seen as both well-established or probably effective. A study on maternal alcohol and other drug use has shown that integrated treatment programs have produced significant results, resulting in higher negative results on toxicology screens. Additionally, brief school-based interventions have been found to be effective in reducing adolescent alcohol and cannabis use and abuse. Motivational interviewing can also be effective in treating substance use disorder in adolescents.

Alcoholics Anonymous and Narcotics Anonymous are widely known self-help organizations in which members support each other abstain from substances. Social skills are significantly impaired in people with alcoholism due to the neurotoxic effects of alcohol on the brain, especially the prefrontal cortex area of the brain. It has been suggested that social skills training adjunctive to inpatient treatment of alcohol dependence is probably efficacious, including managing the social environment.

Medication

A number of medications have been approved for the treatment of substance abuse. These include replacement therapies such as buprenorphine and methadone as well as antagonist medications like disulfiram and naltrexone in either short acting, or the newer long acting form. Several other medications, often ones originally used in other contexts, have also been shown to be effective including bupropion and modafinil. Methadone and buprenorphine are sometimes used to treat opiate addiction. These drugs are used as substitutes for other opioids and still cause withdrawal symptoms but they facilitate the tapering off process in a controlled fashion.

Antipsychotic medications have not been found to be useful. Acamprostate is a glutamatergic NMDA antagonist, which helps with alcohol withdrawal symptoms because alcohol withdrawal is associated with a hyperglutamatergic system.

Heroin-assisted treatment

Three countries in Europe have active HAT programs, namely England, the Netherlands and Switzerland. Despite critical voices by conservative think-tanks with regard to these liberal approaches, significant progress in the reduction of drug-related deaths has been achieved in those countries. For example, the US, devoid of such measures, has seen large increases in drug-related deaths since 2000 (mostly related to heroin use), while Switzerland has seen large decreases. In 2018, approximately 60,000 people have died of drug overdoses in America, while in the same time period, Switzerland's drug deaths were at 260. Relative to the population of these countries, the US has 10 times more drug-related deaths compared to the Swiss Confederation, which in effect illustrates the efficacy of HAT to reduce fatal outcomes in opiate/opioid addiction.

Dual diagnosis

Main article: Dual diagnosis

It is common for individuals with drugs use disorder to have other psychological problems. The terms “dual diagnosis” or “co-occurring disorders,” refer to having a mental health and substance use disorder at the same time. According to the British Association for Psychopharmacology (BAP), “symptoms of psychiatric disorders such as depression, anxiety and psychosis are the rule rather than the exception in patients misusing drugs and/or alcohol.”

Individuals who have a comorbid psychological disorder often have a poor prognosis if either disorder is untreated. Historically most individuals with dual diagnosis either received treatment only for one of their disorders or they didn't receive any treatment all. However, since the 1980s, there has been a push towards integrating mental health and addiction treatment. In this method, neither condition is considered primary and both are treated simultaneously by the same provider.

Epidemiology

Disability-adjusted life year for drug use disorders per 100,000 inhabitants in 2004.

  no data

  <40

  40–80

  80–120

  120–160

  160–200

  200–240

  240–280

  280–320

  320–360

  360–400

  400–440

  >440

The initiation of drug use including alcohol is most likely to occur during adolescence, and some experimentation with substances by older adolescents is common. For example, results from 2010 Monitoring the Future survey, a nationwide study on rates of substance use in the United States, show that 48.2% of 12th graders report having used an illicit drug at some point in their lives. In the 30 days prior to the survey, 41.2% of 12th graders had consumed alcohol and 19.2% of 12th graders had smoked tobacco cigarettes. In 2009 in the United States about 21% of high school students have taken prescription drugs without a prescription. And earlier in 2002, the World Health Organization estimated that around 140 million people were alcohol dependent and another 400 million with alcohol-related problems.

Studies have shown that the large majority of adolescents will phase out of drug use before it becomes problematic. Thus, although rates of overall use are high, the percentage of adolescents who meet criteria for substance abuse is significantly lower (close to 5%). According to BBC, "Worldwide, the UN estimates there are more than 50 million regular users of morphine diacetate (heroin), cocaine and synthetic drugs."

More than 70,200 Americans died from drug overdoses in 2017. Among these, the sharpest increase occurred among deaths related to fentanyl and synthetic opioids (28,466 deaths). See charts below.

• 

  Drug use is higher in countries with high economic inequality

• 

  Total recorded alcohol per capita consumption (15+), in litres of pure alcohol

• 

  Total yearly U.S. drug deaths.

• 

  US yearly overdose deaths, and the drugs involved.

History

APA, AMA, and NCDA

In 1932, the American Psychiatric Association created a definition that used legality, social acceptability, and cultural familiarity as qualifying factors:

…as a general rule, we reserve the term drug abuse to apply to the illegal, nonmedical use of a limited number of substances, most of them drugs, which have properties of altering the mental state in ways that are considered by social norms and defined by statute to be inappropriate, undesirable, harmful, threatening, or, at minimum, culture-alien.

In 1966, the American Medical Association's Committee on Alcoholism and Addiction defined abuse of stimulants (amphetamines, primarily) in terms of 'medical supervision':

…'use' refers to the proper place of stimulants in medical practice; 'misuse' applies to the physician's role in initiating a potentially dangerous course of therapy; and 'abuse' refers to self-administration of these drugs without medical supervision and particularly in large doses that may lead to psychological dependency, tolerance and abnormal behavior.

In 1973, the National Commission on Marijuana and Drug Abuse stated:

...drug abuse may refer to any type of drug or chemical without regard to its pharmacologic actions. It is an eclectic concept having only one uniform connotation: societal disapproval. ... The Commission believes that the term drug abuse must be deleted from official pronouncements and public policy dialogue. The term has no functional utility and has become no more than an arbitrary codeword for that drug use which is presently considered wrong.

DSM

The first edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (published in 1952) grouped alcohol and other drug abuse under Sociopathic Personality Disturbances, which were thought to be symptoms of deeper psychological disorders or moral weakness. The third edition, published in 1980, was the first to recognize substance abuse (including drug abuse) and substance dependence as conditions separate from substance abuse alone, bringing in social and cultural factors. The definition of dependence emphasised tolerance to drugs, and withdrawal from them as key components to diagnosis, whereas abuse was defined as "problematic use with social or occupational impairment" but without withdrawal or tolerance.

In 1987, the DSM-IIIR category "psychoactive substance abuse," which includes former concepts of drug abuse is defined as "a maladaptive pattern of use indicated by...continued use despite knowledge of having a persistent or recurrent social, occupational, psychological or physical problem that is caused or exacerbated by the use (or by) recurrent use in situations in which it is physically hazardous." It is a residual category, with dependence taking precedence when applicable. It was the first definition to give equal weight to behavioural and physiological factors in diagnosis. By 1988, the DSM-IV defines substance dependence as "a syndrome involving compulsive use, with or without tolerance and withdrawal"; whereas substance abuse is "problematic use without compulsive use, significant tolerance, or withdrawal." Substance abuse can be harmful to your health and may even be deadly in certain scenarios. By 1994, The fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM) issued by the American Psychiatric Association, the DSM-IV-TR, defines substance dependence as "when an individual persists in use of alcohol or other drugs despite problems related to use of the substance, substance dependence may be diagnosed." along with criteria for the diagnosis.

DSM-IV-TR defines substance abuse as:

• A. A maladaptive pattern of substance use leading to clinically significant impairment or distress, as manifested by one (or more) of the following, occurring within a 12-month period:

1. Recurrent substance use resulting in a failure to fulfill major role obligations at work, school, or home (e.g., repeated absences or poor work performance related to substance use; substance-related absences, suspensions or expulsions from school; neglect of children or household)
2. Recurrent substance use in situations in which it is physically hazardous (e.g., driving an automobile or operating a machine when impaired by substance use)
3. Recurrent substance-related legal problems (e.g., arrests for substance-related disorderly conduct)
4. Continued substance use despite having persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of the substance (e.g., arguments with spouse about consequences of intoxication, physical fights)

• B. The symptoms have never met the criteria for Substance Dependence for this class of substance.

The fifth edition of the DSM (DSM-5), was released in 2013, and it revisited this terminology. The principal change was a transition from the abuse/dependence terminology. In the DSM-IV era, abuse was seen as an early form or less hazardous form of the disease characterized with the dependence criteria. However, the APA's 'dependence' term, as noted above, does not mean that physiologic dependence is present but rather means that a disease state is present, one that most would likely refer to as an addicted state. Many involved recognize that the terminology has often led to confusion, both within the medical community and with the general public. The American Psychiatric Association requested input as to how the terminology of this illness should be altered as it moves forward with DSM-5 discussion. In the DSM-5, substance abuse and substance dependence have been merged into the category of substance use disorders and they now longer exist as individual concepts. While substance abuse and dependence were either present or not, substance use disorder has three levels of severity: mild, moderate and severe.

Society and culture

Legal approaches

Related articles: Drug control law, Prohibition (drugs), Arguments for and against drug prohibition, Harm reduction

Most governments have designed legislation to criminalize certain types of drug use. These drugs are often called "illegal drugs" but generally what is illegal is their unlicensed production, distribution, and possession. These drugs are also called "controlled substances". Even for simple possession, legal punishment can be quite severe (including the death penalty in some countries). Laws vary across countries, and even within them, and have fluctuated widely throughout history.

1991 Indian postage stamp bearing the slogan – Beware of drugs

Attempts by government-sponsored drug control policy to interdict drug supply and eliminate drug abuse have been largely unsuccessful. In spite of the huge efforts by the U.S., drug supply and purity has reached an all-time high, with the vast majority of resources spent on interdiction and law enforcement instead of public health. In the United States, the number of nonviolent drug offenders in prison exceeds by 100,000 the total incarcerated population in the EU, despite the fact that the EU has 100 million more citizens.

Despite drug legislation (or perhaps because of it), large, organized criminal drug cartels operate worldwide. Advocates of decriminalization argue that drug prohibition makes drug dealing a lucrative business, leading to much of the associated criminal activity.

Some states in the U.S, as of late, have focused on facilitating safe use as opposed to eradicating it. For example, as of 2022, New Jersey has made the effort to expand needle exchange programs throughout the state, passing a bill through legislature that gives control over decisions regarding these types of programs to the state’s department of health. This state level bill is not only significant  for New Jersey, as it could be used as a model for other states to possibly follow as well. This bill is partly a reaction to the issues occurring at local level city governments within the state of New Jersey as of late. One example of this is in the Atlantic City Government which came under lawsuit after they halted the enactment of said programs within their city. This suit came a year before the passing of this bill, stemming from a local level decision to shut down related operations in Atlantic City made in July that same year. This lawsuit highlights the feelings of New Jersey residents, who had a great influence on this bill passing the legislature. These feelings were demonstrated in front of Atlantic City City hall, where residents exclaimed their desire for these programs. All in all, the aforementioned bill was signed effectively into law just days after it passed legislature, by New Jersey Governor Phil Murphy.

Cost

Policymakers try to understand the relative costs of drug-related interventions. An appropriate drug policy relies on the assessment of drug-related public expenditure based on a classification system where costs are properly identified.

Labelled drug-related expenditures are defined as the direct planned spending that reflects the voluntary engagement of the state in the field of illicit drugs. Direct public expenditures explicitly labeled as drug-related can be easily traced back by exhaustively reviewing official accountancy documents such as national budgets and year-end reports. Unlabelled expenditure refers to unplanned spending and is estimated through modeling techniques, based on a top-down budgetary procedure. Starting from overall aggregated expenditures, this procedure estimates the proportion causally attributable to substance abuse (Unlabelled Drug-related Expenditure = Overall Expenditure × Attributable Proportion). For example, to estimate the prison drug-related expenditures in a given country, two elements would be necessary: the overall prison expenditures in the country for a given period, and the attributable proportion of inmates due to drug-related issues. The product of the two will give a rough estimate that can be compared across different countries.

Europe

As part of the reporting exercise corresponding to 2005, the European Monitoring Centre for Drugs and Drug Addiction's network of national focal points set up in the 27 European Union (EU) the Member States, Norway, and the candidates' countries to the EU, were requested to identify labeled drug-related public expenditure, at the country level.

This was reported by 10 countries categorized according to the functions of government, amounting to a total of EUR 2.17 billion. Overall, the highest proportion of this total came within the government functions of Health (66%) (e.g. medical services), and Public Order and Safety (POS) (20%) (e.g. police services, law courts, prisons). By country, the average share of GDP was 0.023% for Health, and 0.013% for POS. However, these shares varied considerably across countries, ranging from 0.00033% in Slovakia, up to 0.053% of GDP in Ireland in the case of Health, and from 0.003% in Portugal, to 0.02% in the UK, in the case of POS; almost a 161-fold difference between the highest and the lowest countries for Health, and a 6-fold difference for POS. Why do Ireland and the UK spend so much in Health and POS, or Slovakia and Portugal so little, in GDP terms?

To respond to this question and to make a comprehensive assessment of drug-related public expenditure across countries, this study compared Health and POS spending and GDP in the 10 reporting countries. Results found suggest GDP to be a major determinant of the Health and POS drug-related public expenditures of a country. Labeled drug-related public expenditure showed a positive association with the GDP across the countries considered: r = 0.81 in the case of Health, and r = 0.91 for POS. The percentage change in Health and POS expenditures due to a one percent increase in GDP (the income elasticity of demand) was estimated to be 1.78% and 1.23% respectively.

Being highly income elastic, Health and POS expenditures can be considered luxury goods; as a nation becomes wealthier it openly spends proportionately more on drug-related health and public order and safety interventions.

United Kingdom

The UK Home Office estimated that the social and economic cost of drug abuse to the UK economy in terms of crime, absenteeism and sickness is in excess of £20 billion a year. However, the UK Home Office does not estimate what portion of those crimes are unintended consequences of drug prohibition (crimes to sustain expensive drug consumption, risky production and dangerous distribution), nor what is the cost of enforcement. Those aspects are necessary for a full analysis of the economics of prohibition.

United States

Year	Cost (billions of dollars)
1992	107
1993	111
1994	117
1995	125
1996	130
1997	134
1998	140
1999	151
2000	161
2001	170
2002	181

These figures represent overall economic costs, which can be divided in three major components: health costs, productivity losses and non-health direct expenditures.

• Health-related costs were projected to total $16 billion in 2002.
• Productivity losses were estimated at $128.6 billion. In contrast to the other costs of drug abuse (which involve direct expenditures for goods and services), this value reflects a loss of potential resources: work in the labor market and in household production that was never performed, but could reasonably be expected to have been performed absent the impact of drug abuse.

Included are estimated productivity losses due to premature death ($24.6 billion), drug abuse-related illness ($33.4 billion), incarceration ($39.0 billion), crime careers ($27.6 billion) and productivity losses of victims of crime ($1.8 billion).

• The non-health direct expenditures primarily concern costs associated with the criminal justice system and crime victim costs, but also include a modest level of expenses for administration of the social welfare system. The total for 2002 was estimated at $36.4 billion. The largest detailed component of these costs is for state and federal corrections at $14.2 billion, which is primarily for the operation of prisons. Another $9.8 billion was spent on state and local police protection, followed by $6.2 billion for federal supply reduction initiatives.

According to a report from the Agency for Healthcare Research and Quality (AHRQ), Medicaid was billed for a significantly higher number of hospitals stays for Opioid drug overuse than Medicare or private insurance in 1993. By 2012, the differences were diminished. Over the same time, Medicare had the most rapid growth in number of hospital stays.

Canada

Substance abuse takes a financial toll on Canada's hospitals and the country as a whole. In the year 2011, around $267 million dollars of hospital services were attributed to dealing with substance abuse problems. Majority of these hospital costs in 2011 were related to issues with alcohol. Additionally, in 2014, Canada also allocated almost $45 million dollars towards battling prescription drug abuse, extending into the year 2019. Most of the financial decisions made on substance abuse in Canada can be attributed to the research conducted by the Canadian Centre on Substance Abuse (CCSA) which conduct both extensive and specific reports. In fact, the CCSA is heavily responsible for identifying Canada's heavy issues with substance abuse. Some examples of reports by the CCSA include a 2013 report on drug use during pregnancy and a 2015 report on adolescence use of cannabis.

Special populations

Immigrants and refugees

Immigrant and refugees have often been under great stress, physical trauma and depression and anxiety due to separation from loved ones often characterize the pre-migration and transit phases, followed by "cultural dissonance," language barriers, racism, discrimination, economic adversity, overcrowding, social isolation, and loss of status and difficulty obtaining work and fears of deportation are common. Refugees frequently experience concerns about the health and safety of loved ones left behind and uncertainty regarding the possibility of returning to their country of origin. For some, substance abuse functions as a coping mechanism to attempt to deal with these stressors.

Immigrants and refugees may bring the substance use and abuse patterns and behaviors of their country of origin, or adopt the attitudes, behaviors, and norms regarding substance use and abuse that exist within the dominant culture into which they are entering.

Street children

Street children in many developing countries are a high risk group for substance misuse, in particular solvent abuse. Drawing on research in Kenya, Cottrell-Boyce argues that "drug use amongst street children is primarily functional – dulling the senses against the hardships of life on the street – but can also provide a link to the support structure of the ‘street family’ peer group as a potent symbol of shared experience."

Musicians

In order to maintain high-quality performance, some musicians take chemical substances. Some musicians take drugs such as alcohol to deal with the stress of performing. As a group they have a higher rate of substance abuse. The most common chemical substance which is abused by pop musicians is cocaine, because of its neurological effects. Stimulants like cocaine increase alertness and cause feelings of euphoria, and can therefore make the performer feel as though they in some ways ‘own the stage’. One way in which substance abuse is harmful for a performer (musicians especially) is if the substance being abused is aspirated. The lungs are an important organ used by singers, and addiction to cigarettes may seriously harm the quality of their performance. Smoking harms the alveoli, which are responsible for absorbing oxygen.

Veterans

Substance abuse can be a factor that affects the physical and mental health of veterans. Substance abuse may also harm personal and familial relationships, leading to financial difficulty. There is evidence to suggest that substance abuse disproportionately affects the homeless veteran population. A 2015 Florida study, which compared causes of homelessness between veterans and non-veteran populations in a self-reporting questionnaire, found that 17.8% of the homeless veteran participants attributed their homelessness to alcohol and other drug-related problems compared to just 3.7% of the non-veteran homeless group.

A 2003 study found that homelessness was correlated with access to support from family/friends and services. However, this correlation was not true when comparing homeless participants who had a current substance-use disorders. The U.S. Department of Veterans Affairs provides a summary of treatment options for veterans with substance-use disorder. For treatments that do not involve medication, they offer therapeutic options that focus on finding outside support groups and “looking at how substance use problems may relate to other problems such as PTSD and depression”.

Sex and gender

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There are many sex differences in substance abuse. Men and Women express differences in the short and long-term effects of substance abuse. These differences can be credited to sexual dimorphisms in brain, endocrine and metabolic systems. Social and environmental factors that tend to disproportionately effect women; such as child and elder care and the risk of exposure to violence are also factors in the gender differences in substance abuse. Women report having greater impairment in areas such as employment, family and social functioning when abusing substances but have a similar response to treatment. Co-occurring psychiatric disorders are more common among women than men who abuse substances; women more frequently use substances to reduce the negative effects of these co-occurring disorders. Substance abuse puts both men and women at higher risk for perpetration and victimization of sexual violence. Men tend to take drugs for the first time to be part of a group and fit in more so than women. At first interaction, women may experience more pleasure from drugs than men do. Women tend to progress more rapidly from first experience to addiction than men. Physicians, psychiatrists and social workers have believed for decades that women escalate alcohol use more rapidly once they start. Once the addictive behavior is established for women they stabilize at higher doses of drugs than males do. When withdrawing from smoking women experience greater stress response. Males experience greater symptoms when withdrawing from alcohol. There are even gender differences when it comes to rehabilitation and relapse rates. For alcohol, relapse rates were very similar for men and women. For women, marriage and marital stress were risk factors for alcohol relapse. For men, being married lowered the risk of relapse. This difference may be a result of gendered differences in excessive drinking. Alcoholic women are much more likely to be married to partners that drink excessively than are alcoholic men. As a result of this, men may be protected from relapse by marriage while women are out at higher risk when married. However, women are less likely than men to experience relapse to substance use. When men experience a relapse to substance use, they more than likely had a positive experience prior to the relapse. On the other hand, when women relapse to substance use, they were more than likely affected by negative circumstances or interpersonal problems.