Psychoactive drug

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An assortment of psychoactive drugs, including both street drugs and medications:
crack cocaine
methylphenidate (Ritalin)
MDMA (ecstasy)
peyote (mescaline)
LSD blotter
psilocybin mushroom (Psilocybe cubensis)
Salvia divinorum
diphenhydramine (Benadryl)
Amanita muscaria mushroom
Tylenol 3 (contains codeine)
codeine with muscle relaxant
pipe tobacco
bupropion (Zyban)
hashish Psychoactive Drugs Legend.jpg
An assortment of psychoactive drugs, including both street drugs and medications:
  1. caffeine
  2. crack cocaine
  3. methylphenidate (Ritalin)
  4. ephedrine
  5. MDMA (ecstasy)
  6. peyote (mescaline)
  7. LSD blotter
  8. psilocybin mushroom ( Psilocybe cubensis )
  9. Salvia divinorum
  10. diphenhydramine (Benadryl)
  11. Amanita muscaria mushroom
  12. Tylenol 3 (contains codeine)
  13. codeine with muscle relaxant
  14. pipe tobacco
  15. bupropion (Zyban)
  16. marijuana
  17. hashish

A psychoactive drug, psychopharmaceutical, psychoactive agent or psychotropic drug is a chemical substance that changes functions of the nervous system, and results in alterations in perception, mood, consciousness, cognition, or behavior. [1]


These substances may be used medically, recreationally, for spiritual reasons - for example, to alter one's consciousness (as with entheogens for ritual, spiritual or shamanic purposes), or for research.

Some categories of psychoactive drugs may be prescribed by physicians [2] and other healthcare practitioners because of their therapeutic value.

Examples of medication categories that may contain potentially beneficial psychoactive drugs include, but are not limited to:

  1. Anesthetics
  2. Analgesics
  3. Anticonvulsants
  4. Anti-Parkinson’s medications
  5. Medications used to treat Neuropsychiatric Disorders (Antidepressants, Anxiolytics, Antipsychotics and Stimulant Medications.)

Some psychoactive substances may be used in detoxification and rehabilitation programs for people who may have become dependent upon, or addicted to, other mind or mood altering substances. Drug rehabilitation attempts to reduce addiction through a combination of psychotherapy, support groups, and sometimes - psychoactive substances.

Psychoactive substances often bring various changes in consciousness and mood that the user may find rewarding and pleasant (e.g., euphoria or a sense of relaxation) or advantageous in an objectively observable or measurable way (e.g. increased alertness). Substances which are rewarding, and thus positively reinforcing, have the potential to induce a state of addiction – compulsive drug use despite negative consequences. In addition, sustained use of some substances may produce physical or psychological dependence, or both, associated with somatic or psychological-emotional withdrawal states respectively.

Psychoactive drug misuse, dependence, and addiction have resulted in legal measures and moral debate. Governmental controls on manufacture, supply, and prescription attempt to reduce problematic medical drug use. Ethical concerns have also been raised about over-use of these drugs clinically, and about their marketing by manufacturers. Popular campaigns to decriminalize [3] or legalize the recreational use of certain drugs (e.g. cannabis) are also ongoing.


Alcohol is a widely used and abused psychoactive drug. The global alcoholic drinks market was expected to exceed $1 trillion in 2013. Beer is the third-most popular drink overall, after water and tea. Liquor store in Breckenridge Colorado.jpg
Alcohol is a widely used and abused psychoactive drug. The global alcoholic drinks market was expected to exceed $1 trillion in 2013. Beer is the third-most popular drink overall, after water and tea.

Psychoactive drug use can be traced to prehistory. There is archaeological evidence of the use of psychoactive substances, mostly plants, dating back at least 10,000 years, and historical evidence of cultural use over the past 5,000 years. [6] The chewing of coca leaves, for example, dates back over 8,000 years ago in Peruvian society. [7] [8]

Medicinal use is one important facet of psychoactive drug usage. However, some have postulated that the urge to alter one's consciousness is as primary as the drive to satiate thirst, hunger, or sexual desire. [9] Supporters of this belief contend that the history of drug use, and even children's desire for spinning, swinging, or sliding indicate that the drive to alter one's state of mind is universal. [10]

One of the first people to articulate this point of view, set aside from a medicinal context, was American author Fitz Hugh Ludlow (1836–1870) in his book The Hasheesh Eater (1857):

[D]rugs are able to bring humans into the neighborhood of divine experience and can thus carry us up from our personal fate and the everyday circumstances of our life into a higher form of reality. It is, however, necessary to understand precisely what is meant by the use of drugs. We do not mean the purely physical craving...That of which we speak is something much higher, namely the knowledge of the possibility of the soul to enter into a lighter being, and to catch a glimpse of deeper insights and more magnificent visions of the beauty, truth, and the divine than we are normally able to spy through the cracks in our prison cell. But there are not many drugs which have the power of stilling such craving. The entire catalog, at least to the extent that research has thus far written it, may include only opium, hashish, and in rarer cases alcohol, which has enlightening effects only upon very particular characters. [11]

During the 20th century, many governments across the world initially responded to the use of recreational drugs by banning them, and making their use, supply, or trade a criminal offense. A notable example of this was Prohibition in the United States, where alcohol was made illegal for 13 years. However, many governments, government officials, and persons in law enforcement have concluded that illicit drug use cannot be sufficiently stopped through criminalization. Organizations such as Law Enforcement Against Prohibition (LEAP) have come to such a conclusion, believing:

[T]he existing drug policies have failed in their intended goals of addressing the problems of crime, drug abuse, addiction, juvenile drug use, stopping the flow of illegal drugs into this country and the internal sale and use of illegal drugs. By fighting a war on drugs the government has increased the problems of society and made them far worse. A system of regulation rather than prohibition is a less harmful, more ethical and a more effective public policy. [12] [ failed verification ]

In some countries, there has been a move toward harm reduction by health services, where the use of illicit drugs is neither condoned nor promoted, but services and support are provided to ensure users have adequate factual information readily available, and that the negative effects of their use be minimized. Such is the case of the Portuguese drug policy of decriminalization, which achieved its primary goal of reducing the adverse health effects of drug abuse. [13]


Psychoactive substances are used by humans for a number of different purposes, and these uses vary widely between cultures. Some substances may have controlled or illegal uses, some may have shamanic purposes, and others are used medicinally. Other examples include social drinking, nootropic, or sleep aids. Caffeine is the world's most widely consumed psychoactive substance, but unlike many others, it is legal and unregulated in nearly all jurisdictions. In North America, 90% of adults consume caffeine daily. [14]

Psychoactive drugs are divided into different groups according to their pharmacological effects. Commonly used psychoactive drugs and groups are listed below:

Example: benzodiazepines such as Xanax and Valium, barbiturates
Example: MDMA (ecstasy), MDA, 6-APB, AMT
Examples: amphetamine, caffeine, cocaine, nicotine, modafinil
Examples: Ethanol (alcohol), opioids such as morphine, fentanyl, and codeine, cannabis, barbiturates, benzodiazepines.
Examples: psilocybin, LSD, DMT (N,N-Dimethyltryptamine)/ayahuasca, mescaline, Salvia divinorum, Nitrous oxide, and Scopolamine



General anesthetics are a class of psychoactive drug used on people to block physical pain and other sensations. Most anesthetics induce unconsciousness, allowing the person to undergo medical procedures like surgery, without the feelings of physical pain or emotional trauma. [16] To induce unconsciousness, anesthetics affect the GABA and NMDA systems. For example, propofol is a GABA agonist, [17] and ketamine is an NMDA receptor antagonist. [18]

Pain management

Psychoactive drugs are often prescribed to manage pain. The subjective experience of pain is primarily regulated by endogenous opioid peptides. Thus, pain can often be managed using psychoactives that operate on this neurotransmitter system, also known as opioid receptor agonists. This class of drugs can be highly addictive, and includes opiate narcotics, like morphine and codeine. [19] NSAIDs, such as aspirin and ibuprofen, are also analgesics. These agents also reduce eicosanoid-mediated inflammation by inhibiting the enzyme cyclooxygenase.

Mental disorders

Zoloft (sertraline) is an SSRI antidepressant. Zoloft bottles.jpg
Zoloft (sertraline) is an SSRI antidepressant.

Psychiatric medications are psychoactive drugs prescribed for the management of mental and emotional disorders, or to aid in overcoming challenging behavior. [20] There are six major classes of psychiatric medications:

In addition, several psychoactive substances are currently employed to treat various addictions. These include acamprosate or naltrexone in the treatment of alcoholism, or methadone or buprenorphine maintenance therapy in the case of opioid addiction. [22]

Exposure to psychoactive drugs can cause changes to the brain that counteract or augment some of their effects; these changes may be beneficial or harmful. However, there is a significant amount of evidence that the relapse rate of mental disorders negatively corresponds with the length of properly followed treatment regimens (that is, relapse rate substantially declines over time), and to a much greater degree than placebo. [23]


Many psychoactive substances are used for their mood and perception altering effects, including those with accepted uses in medicine and psychiatry. Examples of psychoactive substances include caffeine, alcohol, cocaine, LSD, nicotine and cannabis. [24] Classes of drugs frequently used recreationally include:

In some modern and ancient cultures, drug usage is seen as a status symbol. Recreational drugs are seen as status symbols in settings such as at nightclubs and parties. [25] For example, in ancient Egypt, gods were commonly pictured holding hallucinogenic plants. [26]

Because there is controversy about regulation of recreational drugs, there is an ongoing debate about drug prohibition. Critics of prohibition believe that regulation of recreational drug use is a violation of personal autonomy and freedom. [27] In the United States, critics have noted that prohibition or regulation of recreational and spiritual drug use might be unconstitutional, and causing more harm than is prevented. [28]

Some people who take psychoactive drugs experience drug or substance induced psychosis. A 2019 systematic review and meta-analysis by Murrie et al. found that the pooled proportion of transition from substance-induced psychosis to schizophrenia was 25% (95% CI 18%–35%), compared with 36% (95% CI 30%–43%) for brief, atypical and not otherwise specified psychoses. [29] Type of substance was the primary predictor of transition from drug-induced psychosis to schizophrenia, with highest rates associated with cannabis (6 studies, 34%, CI 25%–46%), hallucinogens (3 studies, 26%, CI 14%–43%) and amphetamines (5 studies, 22%, CI 14%–34%). Lower rates were reported for opioid (12%), alcohol (10%) and sedative (9%) induced psychoses. Transition rates were slightly lower in older cohorts but were not affected by sex, country of the study, hospital or community location, urban or rural setting, diagnostic methods, or duration of follow-up. [29]

Ritual and spiritual

Timothy Leary was a leading proponent of spiritual hallucinogen use. Timothy-Leary-Los-Angeles-1989.jpg
Timothy Leary was a leading proponent of spiritual hallucinogen use.

Certain psychoactives, particularly hallucinogens, have been used for religious purposes since prehistoric times. Native Americans have used peyote cacti containing mescaline for religious ceremonies for as long as 5700 years. [30] The muscimol-containing Amanita muscaria mushroom was used for ritual purposes throughout prehistoric Europe. [31]

The use of entheogens for religious purposes resurfaced in the West during the counterculture movements of the 1960s and 70s. Under the leadership of Timothy Leary, new spiritual and intention-based movements began to use LSD and other hallucinogens as tools to access deeper inner exploration. In the United States, the use of peyote for ritual purposes is protected only for members of the Native American Church, which is allowed to cultivate and distribute peyote. However, the genuine religious use of peyote, regardless of one's personal ancestry, is protected in Colorado, Arizona, New Mexico, Nevada, and Oregon. [32]


Psychoactive drugs have been used in military applications as non-lethal weapons.

Both military and civilian American intelligence officials are known to have used psychoactive drugs while interrogating captives apprehended in its "war on terror". In July 2012 Jason Leopold and Jeffrey Kaye, psychologists and human rights workers, had a Freedom of Information Act request fulfilled that confirmed that the use of psychoactive drugs during interrogation was a long-standing practice. [33] [34] Captives and former captives had been reporting medical staff collaborating with interrogators to drug captives with powerful psychoactive drugs prior to interrogation since the very first captives release. [35] [36] In May 2003 recently released Pakistani captive Sha Mohammed Alikhel described the routine use of psychoactive drugs. He said that Jihan Wali, a captive kept in a nearby cell, was rendered catatonic through the use of these drugs.[ citation needed ]

Additionally, militaries worldwide have used or are using various psychoactive drugs to improve performance of soldiers by suppressing hunger, increasing the ability to sustain effort without food, increasing and lengthening wakefulness and concentration, suppressing fear, reducing empathy, and improving reflexes and memory-recall among other things. [37] [38]

The first documented case of a soldier overdosing on methamphetamine during combat, was the Finnish corporal Aimo Koivunen, a soldier who fought in the Winter War and the Continuation War. [39] [40]

Route of administration

Psychoactive drugs are administered via oral ingestion as a tablet, capsule, powder, liquid, and beverage; via injection by subcutaneous, intramuscular, and intravenous route; via rectum by suppository and enema; and via inhalation by smoking, vaporizing, and snorting. The efficiency of each method of administration varies from drug to drug. [41]

The psychiatric drugs fluoxetine, quetiapine, and lorazepam are ingested orally in tablet or capsule form. Alcohol and caffeine are ingested in beverage form; nicotine and cannabis are smoked or vaporized; peyote and psilocybin mushrooms are ingested in botanical form or dried; and crystalline drugs such as cocaine and methamphetamine are usually inhaled or snorted.

Determinants of effects

The theory of dosage, set, and setting is a useful model in dealing with the effects of psychoactive substances, especially in a controlled therapeutic setting as well as in recreational use. Dr. Timothy Leary, based on his own experiences and systematic observations on psychedelics, developed this theory along with his colleagues Ralph Metzner, and Richard Alpert (Ram Dass) in the 1960s. [42]


The first factor, dosage, has been a truism since ancient times, or at least since Paracelsus who said, "Dose makes the poison." Some compounds are beneficial or pleasurable when consumed in small amounts, but harmful, deadly, or evoke discomfort in higher doses.


The set is the internal attitudes and constitution of the person, including their expectations, wishes, fears, and sensitivity to the drug. This factor is especially important for the hallucinogens, which have the ability to make conscious experiences out of the unconscious. In traditional cultures, set is shaped primarily by the worldview, health and genetic characteristics that all the members of the culture share.


The third aspect is setting, which pertains to the surroundings, the place, and the time in which the experiences transpire.

This theory clearly states that the effects are equally the result of chemical, pharmacological, psychological, and physical influences. The model that Timothy Leary proposed applied to the psychedelics, although it also applies to other psychoactives. [43]


Illustration of the major elements of neurotransmission. Depending on its method of action, a psychoactive substance may block the receptors on the post-synaptic neuron (dendrite), or block reuptake or affect neurotransmitter synthesis in the pre-synaptic neuron (axon). SynapseSchematic en.svg
Illustration of the major elements of neurotransmission. Depending on its method of action, a psychoactive substance may block the receptors on the post-synaptic neuron (dendrite), or block reuptake or affect neurotransmitter synthesis in the pre-synaptic neuron (axon).

Psychoactive drugs operate by temporarily affecting a person's neurochemistry, which in turn causes changes in a person's mood, cognition, perception and behavior. There are many ways in which psychoactive drugs can affect the brain. Each drug has a specific action on one or more neurotransmitter or neuroreceptor in the brain.

Drugs that increase activity in particular neurotransmitter systems are called agonists. They act by increasing the synthesis of one or more neurotransmitters, by reducing its reuptake from the synapses, or by mimicking the action by binding directly to the postsynaptic receptor. Drugs that reduce neurotransmitter activity are called antagonists, and operate by interfering with synthesis or blocking postsynaptic receptors so that neurotransmitters cannot bind to them. [44]

Exposure to a psychoactive substance can cause changes in the structure and functioning of neurons, as the nervous system tries to re-establish the homeostasis disrupted by the presence of the drug (see also, neuroplasticity). Exposure to antagonists for a particular neurotransmitter can increase the number of receptors for that neurotransmitter or the receptors themselves may become more responsive to neurotransmitters; this is called sensitization. Conversely, overstimulation of receptors for a particular neurotransmitter may cause a decrease in both number and sensitivity of these receptors, a process called desensitization or tolerance. Sensitization and desensitization are more likely to occur with long-term exposure, although they may occur after only a single exposure. These processes are thought to play a role in drug dependence and addiction. [45] Physical dependence on antidepressants or anxiolytics may result in worse depression or anxiety, respectively, as withdrawal symptoms. Unfortunately, because clinical depression (also called major depressive disorder) is often referred to simply as depression, antidepressants are often requested by and prescribed for patients who are depressed, but not clinically depressed.

Affected neurotransmitter systems

The following is a brief table of notable drugs and their primary neurotransmitter, receptor or method of action. Many drugs act on more than one transmitter or receptor in the brain. [46]

Cholinergics (acetylcholine receptor agonists) arecoline, nicotine, piracetam
Muscarinic antagonists (acetylcholine receptor antagonists) scopolamine, benzatropine, dimenhydrinate, diphenhydramine, trihexiphenidyl, doxylamine, atropine, quetiapine, olanzapine, most tricyclics
Nicotinic antagonists (acetylcholine receptor antagonists) memantine, bupropion
Adenosine receptor antagonists [47] caffeine, theobromine, theophylline
Dopamine reuptake inhibitors cocaine , bupropion , methylphenidate , St John's wort, and certain TAAR1 agonists like amphetamine, phenethylamine, and methamphetamine
Dopamine releasing agents Cavendish bananas, [48] TAAR1 agonists like amphetamine, phenethylamine, and methamphetamine
Dopamine agonists pramipexole, Ropinirole, L-DOPA (prodrug), memantine
Dopamine antagonists haloperidol, droperidol , many antipsychotics (e.g., risperidone, olanzapine, quetiapine )
Dopamine partial agonists LSD, aripiprazole
Gamma-Aminobuttersaure - gamma-aminobutyric acid.svg
GABA reuptake inhibitors tiagabine, St John's wort, vigabatrin, deramciclane
GABAA receptor agonists ethanol, niacin, [49] barbiturates, diazepam, clonazepam, lorazepam, temazepam, alprazolam and other benzodiazepines, zolpidem, eszopiclone, zaleplon and other nonbenzodiazepines, muscimol , phenibut
GABAA receptor positive allosteric modulators
GABA receptor antagonists thujone, bicuculline
GABAA receptor negative allosteric modulators
Norepinephrine structure with descriptor.svg
Norepinephrine reuptake inhibitors St John's wort , [50] most non-SSRI antidepressants such as amoxapine, atomoxetine, bupropion, venlafaxine, quetiapine , the tricyclics, methylphenidate , SNRIs such as duloxetine, venlafaxine, cocaine , tramadol , and certain TAAR1 agonists like amphetamine, phenethylamine, methamphetamine .
Norepinephrine releasing agents ephedrine, PPA, pseudoephedrine, amphetamine, phenethylamine, methamphetamine
Adrenergic agonists clonidine, guanfacine, phenylephrine
Adrenergic antagonists carvedilol, metoprolol, mianserin, prazosin, propranolol, trazodone, yohimbine, olanzapine
Serotonin receptor agonists triptans (e.g. sumatriptan, eletriptan), psychedelics (e.g. lysergic acid diethylamide, psilocybin, mescaline), ergolines (e.g. lisuride, bromocriptine)
Serotonin reuptake inhibitors most antidepressants including St John's wort , tricyclics such as imipramine , SSRIs (e.g. fluoxetine , sertraline , escitalopram ), SNRIs (e.g. duloxetine , venlafaxine )
Serotonin releasing agents fenfluramine , MDMA (ecstasy), tryptamine
Serotonin receptor antagonists ritanserin , mirtazapine , mianserin , trazodone , cyproheptadine , memantine , atypical antipsychotics (e.g., risperidone , olanzapine , quetiapine )
AMPA receptor positive allosteric modulators aniracetam, CX717, piracetam
AMPA receptor antagonists kynurenic acid, NBQX, topiramate
Cannabinoid receptor agonists JWH-018
Cannabinoid receptor partial agonists Anandamide , THC , cannabidiol , cannabinol
Cannabinoid receptor inverse agonists Rimonabant
Anandamide reuptake inhibitors LY 2183240 , VDM 11 , AM 404
FAAH enzyme inhibitors MAFP , URB597 , N-Arachidonylglycine
NMDA receptor antagonists ethanol, ketamine, deschloroketamine, 2-Fluorodeschloroketamine, PCP, DXM, Nitrous Oxide, memantine
GHB receptor agonistsGHB, T-HCA
Sigma receptor Sigma-1 receptor agonists cocaine, DMT, DXM, fluvoxamine, ibogaine, opipramol, PCP, methamphetamine
Sigma-2 receptor agonists methamphetamine
Opioid receptor μ-opioid receptor agonistsNarcotic opioids (e.g. codeine, morphine, hydrocodone, hydromorphone, oxycodone, oxymorphone, heroin, fentanyl)
μ-opioid receptor partial agonists buprenorphine
μ-opioid receptor inverse agonists naloxone
μ-opioid receptor antagonists naltrexone
κ-opioid receptor agonists salvinorin A, butorphanol, nalbuphine, pentazocine, ibogaine [51]
κ-opioid receptor antagonists buprenorphine
H1 receptor antagonists diphenhydramine, doxylamine, mirtazapine, mianserin, quetiapine, olanzapine, meclozine , most tricyclics
H3 receptor antagonists pitolisant
Indirect histamine receptor agonists modafinil [52]
Monoamine oxidase inhibitors (MAOIs) phenelzine, iproniazid, tranylcypromine, selegiline, rasagiline, moclobemide, isocarboxazid, Linezolid, benmoxin, St John's wort, coffee, [53] garlic [54]
Melatonin receptor agonists agomelatine, melatonin, ramelteon, tasimelteon
Imidazoline receptor agonists apraclonidine, clonidine, moxonidine, rilmenidine
Orexin receptor Inderict Orexin receptor agonists modafinil [55]
Orexin receptor antagonists SB-334,867, SB-408,124, TCS-OX2-29, suvorexant

Addiction and dependence

Addiction and dependence glossary [56] [57] [58] [59]
  • addiction – a biopsychosocial disorder characterized by persistent use of drugs (including alcohol) despite substantial harm and adverse consequences
  • addictive drug – psychoactive substances that with repeated use are associated with significantly higher rates of substance use disorders, due in large part to the drug's effect on brain reward systems
  • dependence – an adaptive state associated with a withdrawal syndrome upon cessation of repeated exposure to a stimulus (e.g., drug intake)
  • drug sensitization or reverse tolerance – the escalating effect of a drug resulting from repeated administration at a given dose
  • drug withdrawal – symptoms that occur upon cessation of repeated drug use
  • physical dependence – dependence that involves persistent physical–somatic withdrawal symptoms (e.g., fatigue and delirium tremens)
  • psychological dependence – dependence that involves emotional–motivational withdrawal symptoms (e.g., dysphoria and anhedonia)
  • reinforcing stimuli – stimuli that increase the probability of repeating behaviors paired with them
  • rewarding stimuli – stimuli that the brain interprets as intrinsically positive and desirable or as something to approach
  • sensitization – an amplified response to a stimulus resulting from repeated exposure to it
  • substance use disorder – a condition in which the use of substances leads to clinically and functionally significant impairment or distress
  • tolerance – the diminishing effect of a drug resulting from repeated administration at a given dose
Comparison of the perceived harm for various psychoactive drugs from a poll among medical psychiatrists specialized in addiction treatment (David Nutt et al. 2007) Development of a rational scale to assess the harm of drugs of potential misuse (physical harm and dependence, NA free means).svg
Comparison of the perceived harm for various psychoactive drugs from a poll among medical psychiatrists specialized in addiction treatment (David Nutt et al. 2007)

Psychoactive drugs are often associated with addiction or drug dependence. Dependence can be divided into two types: psychological dependence, by which a user experiences negative psychological or emotional withdrawal symptoms (e.g., depression) and physical dependence, by which a user must use a drug to avoid physically uncomfortable or even medically harmful physical withdrawal symptoms. [61] Drugs that are both rewarding and reinforcing are addictive; these properties of a drug are mediated through activation of the mesolimbic dopamine pathway, particularly the nucleus accumbens. Not all addictive drugs are associated with physical dependence, e.g., amphetamine, and not all drugs that produce physical dependence are addictive drugs, e.g., caffeine.

Many professionals, self-help groups, and businesses specialize in drug rehabilitation, with varying degrees of success, and many parents attempt to influence the actions and choices of their children regarding psychoactives. [62]

Common forms of rehabilitation include psychotherapy, support groups and pharmacotherapy, which uses psychoactive substances to reduce cravings and physiological withdrawal symptoms while a user is going through detox. Methadone, itself an opioid and a psychoactive substance, is a common treatment for heroin addiction, as is another opioid, buprenorphine. Recent research on addiction has shown some promise in using psychedelics such as ibogaine to treat and even cure drug addictions, although this has yet to become a widely accepted practice. [63] [64]


Historical image of legal heroin bottle Bayer Heroin bottle.jpg
Historical image of legal heroin bottle

The legality of psychoactive drugs has been controversial through most of recent history; the Second Opium War and Prohibition are two historical examples of legal controversy surrounding psychoactive drugs. However, in recent years, the most influential document regarding the legality of psychoactive drugs is the Single Convention on Narcotic Drugs, an international treaty signed in 1961 as an Act of the United Nations. Signed by 73 nations including the United States, the USSR, Pakistan, India, and the United Kingdom, the Single Convention on Narcotic Drugs established Schedules for the legality of each drug and laid out an international agreement to fight addiction to recreational drugs by combatting the sale, trafficking, and use of scheduled drugs. [65] All countries that signed the treaty passed laws to implement these rules within their borders. However, some countries that signed the Single Convention on Narcotic Drugs, such as the Netherlands, are more lenient with their enforcement of these laws. [66]

In the United States, the Food and Drug Administration (FDA) has authority over all drugs, including psychoactive drugs. The FDA regulates which psychoactive drugs are over the counter and which are only available with a prescription. [67] However, certain psychoactive drugs, like alcohol, tobacco, and drugs listed in the Single Convention on Narcotic Drugs are subject to criminal laws. The Controlled Substances Act of 1970 regulates the recreational drugs outlined in the Single Convention on Narcotic Drugs. [68] Alcohol is regulated by state governments, but the federal National Minimum Drinking Age Act penalizes states for not following a national drinking age. [69] Tobacco is also regulated by all fifty state governments. [70] Most people accept such restrictions and prohibitions of certain drugs, especially the "hard" drugs, which are illegal in most countries. [71] [72] [73]

In the medical context, psychoactive drugs as a treatment for illness is widespread and generally accepted. Little controversy exists concerning over the counter psychoactive medications in antiemetics and antitussives. Psychoactive drugs are commonly prescribed to patients with psychiatric disorders. However, certain critics [ who? ] believe that certain prescription psychoactives, such as antidepressants and stimulants, are overprescribed and threaten patients' judgement and autonomy. [74] [75]

Effect on animals

A number of animals consume different psychoactive plants, animals, berries and even fermented fruit, becoming intoxicated, such as cats after consuming catnip. Traditional legends of sacred plants often contain references to animals that introduced humankind to their use. [76] Animals and psychoactive plants appear to have co-evolved, possibly explaining why these chemicals and their receptors exist within the nervous system. [77]

Widely used psychoactive drugs

This is a list of commonly used drugs that contain psychoactive ingredients. Please note that the following lists contains legal and illegal drugs (based on the country's laws).

See also

Related Research Articles

<span class="mw-page-title-main">Recreational drug use</span> Use of drugs with the primary intention to alter the state of consciousness

Recreational drug use is the use of one or more psychoactive drugs to induce an altered state of consciousness either for pleasure or for some other casual purpose or pastime. When a psychoactive drug enters the user's body, it induces an intoxicating effect. Generally, recreational drugs are divided into three categories: depressants, stimulants, and hallucinogens.

<span class="mw-page-title-main">Psychopharmacology</span> Study of the effects of psychoactive drugs

Psychopharmacology is the scientific study of the effects drugs have on mood, sensation, thinking, behavior, judgment and evaluation, and memory. It is distinguished from neuropsychopharmacology, which emphasizes the correlation between drug-induced changes in the functioning of cells in the nervous system and changes in consciousness and behavior.

Drug withdrawal, drug withdrawal syndrome, or substance withdrawal syndrome, is the group of symptoms that occur upon the abrupt discontinuation or decrease in the intake of pharmaceutical or recreational drugs.

A depressant, or central depressant, is a drug that lowers neurotransmission levels, which is to depress or reduce arousal or stimulation, in various areas of the brain. Depressants are also colloquially referred to as downers as they lower the level of arousal when taken. Stimulants or "uppers" increase mental or physical function, hence the opposite drug class of depressants is stimulants, not antidepressants.

Self-medication is a human behavior in which an individual uses a substance or any exogenous influence to self-administer treatment for physical or psychological conditions: for example headaches or fatigue.

Physical dependence is a physical condition caused by chronic use of a tolerance-forming drug, in which abrupt or gradual drug withdrawal causes unpleasant physical symptoms. Physical dependence can develop from low-dose therapeutic use of certain medications such as benzodiazepines, opioids, antiepileptics and antidepressants, as well as the recreational misuse of drugs such as alcohol, opioids and benzodiazepines. The higher the dose used, the greater the duration of use, and the earlier age use began are predictive of worsened physical dependence and thus more severe withdrawal syndromes. Acute withdrawal syndromes can last days, weeks or months. Protracted withdrawal syndrome, also known as post-acute-withdrawal syndrome or "PAWS", is a low-grade continuation of some of the symptoms of acute withdrawal, typically in a remitting-relapsing pattern, often resulting in relapse and prolonged disability of a degree to preclude the possibility of lawful employment. Protracted withdrawal syndrome can last for months, years, or depending on individual factors, indefinitely. Protracted withdrawal syndrome is noted to be most often caused by benzodiazepines. To dispel the popular misassociation with addiction, physical dependence to medications is sometimes compared to dependence on insulin by persons with diabetes.

Neuropharmacology is the study of how drugs affect function in the nervous system, and the neural mechanisms through which they influence behavior. There are two main branches of neuropharmacology: behavioral and molecular. Behavioral neuropharmacology focuses on the study of how drugs affect human behavior (neuropsychopharmacology), including the study of how drug dependence and addiction affect the human brain. Molecular neuropharmacology involves the study of neurons and their neurochemical interactions, with the overall goal of developing drugs that have beneficial effects on neurological function. Both of these fields are closely connected, since both are concerned with the interactions of neurotransmitters, neuropeptides, neurohormones, neuromodulators, enzymes, second messengers, co-transporters, ion channels, and receptor proteins in the central and peripheral nervous systems. Studying these interactions, researchers are developing drugs to treat many different neurological disorders, including pain, neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease, psychological disorders, addiction, and many others.

Substance dependence, also known as drug dependence, is a biopsychological situation whereby an individual's functionality is dependent on the necessitated re-consumption of a psychoactive substance because of an adaptive state that has developed within the individual from psychoactive substance consumption that results in the experience of withdrawal and that necessitates the re-consumption of the drug. A drug addiction, a distinct concept from substance dependence, is defined as compulsive, out-of-control drug use, despite negative consequences. An addictive drug is a drug which is both rewarding and reinforcing. ΔFosB, a gene transcription factor, is now known to be a critical component and common factor in the development of virtually all forms of behavioral and drug addictions, but not dependence.

Cross-tolerance is a phenomenon that occurs when tolerance to the effects of a certain drug produces tolerance to another drug. It often happens between two drugs with similar functions or effects—for example, acting on the same cell receptor or affecting the transmission of certain neurotransmitters. Cross-tolerance has been observed with pharmaceutical drugs such as anti-anxiety agents and illicit substances, and sometimes the two of them together. Often, a person who uses one drug can be tolerant to a drug that has a completely different function. This phenomenon allows one to become tolerant to a drug that they have never used before.

<span class="mw-page-title-main">Polysubstance use</span> Use of multiple psychoactive substances

Polysubstance use or poly drug use refers to the use of combined psychoactive substances. Polysubstance use may be used for entheogenic, recreational, or off-label indications, with both legal and illegal substances. In many cases one drug is used as a base or primary drug, with additional drugs to leaven or compensate for the side effects, or tolerance, of the primary drug and make the experience more enjoyable with drug synergy effects, or to supplement for primary drug when supply is low.

Sex and drugs date back to ancient humans and have been interlocked throughout human history. Both legal and illegal, the consumption of drugs and their effects on the human body encompasses all aspects of sex, including desire, performance, pleasure, conception, gestation, and disease.

<span class="mw-page-title-main">Nalmefene</span> Opioid antagonist

Nalmefene is an opioid antagonist medication used in the management of opioid overdose and alcohol dependence. It is taken by mouth or by injection.

<span class="mw-page-title-main">Drug</span> Substance having effect(s) on the body of an individual

A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via inhalation, injection, smoking, ingestion, absorption via a patch on the skin, suppository, or dissolution under the tongue.

Dual diagnosis is the condition of having a mental illness and a comorbid substance use disorder. There is considerable debate surrounding the appropriateness of using a single category for a heterogeneous group of individuals with complex needs and a varied range of problems. The concept can be used broadly, for example depression and alcohol use disorder, or it can be restricted to specify severe mental illness and substance use disorder, or a person who has a milder mental illness and a drug dependency, such as panic disorder or generalized anxiety disorder and is dependent on opioids. Diagnosing a primary psychiatric illness in people who use substances is challenging as substance use disorder itself often induces psychiatric symptoms, thus making it necessary to differentiate between substance induced and pre-existing mental illness.

Psychological dependence is a cognitive disorder that involves emotional–motivational withdrawal symptoms—e.g. anxiety and anhedonia—upon cessation of prolonged drug abuse or certain repetitive behaviors. It develops through frequent exposure to a psychoactive substance or behavior, though behavioral dependence is less talked about. The specific mechanism involves a neuronal counter-adaption, which could be mediated through changes in neurotransmitter activity or altered receptor expression. Environmental enrichment and physical activity can attenuate withdrawal symptoms. Psychological dependence is not to be confused with physical dependence, which induces physical withdrawal symptoms upon discontinuation of use. However, they are not mutually exclusive.

Substance-induced psychosis is a form of psychosis that is attributed to substance use. It is a psychosis that results from the effects of chemicals or drugs, including those produced by the body itself. Various psychoactive substances have been implicated in causing or worsening psychosis in users.

<span class="mw-page-title-main">Substance use disorder</span> Continual use of drugs (including alcohol) despite detrimental consequences

Substance use disorder (SUD) is the persistent use of drugs despite substantial harm and adverse consequences as a result of their use. Substance use disorders are characterized by an array of mental/emotional, physical, and behavioral problems such as chronic guilt; an inability to reduce or stop consuming the substance(s) despite repeated attempts; operating vehicles while intoxicated; and physiological withdrawal symptoms. Drug classes that are commonly involved in SUD include: alcohol (alcoholism); cannabis; opioids; stimulants such as nicotine, cocaine and amphetamines; benzodiazepines; barbiturates; and other or unknown substances.

<span class="mw-page-title-main">Addiction</span> Disease resulting in compulsive engagement in rewarding stimuli despite adverse consequences

Addiction is a neuropsychological disorder characterized by a persistent and intense urge to engage in certain behaviors, one of which is the usage of a drug, despite substantial harm and other negative consequences. Repetitive drug use alters brain function in ways that perpetuate craving, and weakens self-control. This phenomenon – drugs reshaping brain function – has led to an understanding of addiction as a brain disorder with a complex variety of psychosocial as well as neurobiological factors that are implicated in addiction's development. Classic signs of addiction include compulsive engagement in rewarding stimuli, preoccupation with substances or behavior, and continued use despite negative consequences. Habits and patterns associated with addiction are typically characterized by immediate gratification, coupled with delayed deleterious effects.

<span class="mw-page-title-main">Cannabis use disorder</span> Continued use of cannabis despite clinically significant impairment

Cannabis use disorder (CUD), also known as cannabis addiction or marijuana addiction, is defined in the fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) and ICD-10 as the continued use of cannabis despite clinically significant impairment.

<span class="mw-page-title-main">Prescription drug addiction</span> Medical condition

Prescription drug addiction is the chronic, repeated use of a prescription drug in ways other than prescribed for, including using someone else’s prescription. A prescription drug is a pharmaceutical drug that may not be dispensed without a legal medical prescription. Drugs in this category are supervised due to their potential for misuse and Substance use disorder. The classes of medications most commonly abused are opioids, central nervous system (CNS) depressants and central nervous stimulants. In particular, prescription opioid is most commonly abused in the form of prescription analgesics.


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