Refraining from alcohol or drug use. The term “abstinence” should not be confused with the term “abstinence syndrome”, which refers to a withdrawal syndrome.

In chemical terminology, alcohols are a large group of organic compounds derived from hydrocarbons and containing one or more hydroxyl (-OH) groups. Ethanol (C2H5OH, ethyl alcohol) is one of this class of compounds, and is the main psychoactive ingredient in alcoholic beverages. By extension the term “alcohol” is also used to refer to alcoholic beverages. Alcohol is a sedative/hypnotic with effects similar to those of barbiturates.

A substance that counteracts the effects of another agent. Pharmacologically, an antagonist interacts with a receptor to inhibit the action of agents (agonists) that produce specific physiological or behavioural effects mediated by that receptor.

One of a class of sympathomimetic amines with powerful stimulant actions on the central nervous system. The class includes amphetamine, dexamphetamine, and methamphetamine. Pharmacologically related drugs include methylphenidate, phenmetrazine and amphepramone (diethylpropion).

One of a group of central nervous system depressants that chemically are substituted derivatives of barbituric acid; examples are amobarbital, pento-barbital, phenobarbital, and secobarbital. They are used as anti epileptics, anaesthetics, sedatives, hypnotics and, less commonly, as anxiolytics or anti-anxiety drugs (see sedative/hypnotic). Acute and chronic use induces effects similar to those of alcohol.

One of a group of structurally related drugs used mainly as sedatives/hypnotics, muscle relaxants, and antiepileptics, and once referred to by the now-deprecated term “minor tranquillisers”. These agents are believed to produce therapeutic effects by potentiating the action of gamma-aminobutyric acid (GABA), a major inhibitory neurotransmitter.

Diseases such as HIV and Hepatitis B and C, which are spread by blood-to-blood contact (e.g. needle-sharing).

A generic term used to denote the several psychoactive preparations of the marijuana (hemp) plant, Cannabis sativa. They include marijuana leaf (in street jargon: grass, pot, dope, weed or reefers), bhang, ganja or hashish (derived from the resin of the flowering heads of the plant), and hashish oil.

An alkaloid obtained from coca leaves or synthesized from ecgonine or its derivatives. Cocaine hydrochloride was commonly used as a local anaesthetic in dentistry, ophthalmology, and in ear, nose and throat surgery because its strong vasoconstrictor action helps to reduce local bleeding. Cocaine is a powerful central nervous system stimulant used non-medically to produce euphoria or wakefulness. Repeated use produces dependence.

A cluster of physiological, behavioural and cognitive phenomena in which the use of a substance or a class of substances takes on a much higher priority for a given individual than other behaviours that once had greater value. A central descriptive characteristic of the dependence syndrome is the desire (often strong, sometimes overpowering) to take psychoactive drugs (which may or may not have been medically prescribed), alcohol, or tobacco.

Also referred to as a managed withdrawal or supported withdrawal, detoxification refers to the process of an individual being withdrawn from the effects of a psychoactive substance. When referring to a clinical procedure, detoxification refers to a withdrawal process that is carried out in a safe and effective manner, minimizing the withdrawal symptoms, and supporting the person physically and mentally through the process.

Any of the range of adverse accompaniments of drug use, particularly illicit drug use. “Related” does not necessarily imply causality.

A pattern of retarded growth and development, both neuropsychological and physical, with typical facial dysmorphic features, found in some children exposed to alcohol during pregnancy. A spectrum of physical and neurodevelopmental abnormalities, which includes FAS, has been attributed to the effects of alcohol on the fetus. The level of maternal consumption that produces Fetal Alcohol Spectrum Disorders (FASD) has not been established and is influenced by genetic and other maternal and fetal characteristics.

A pattern of psychoactive substance use that causes damage to health (ICD-10, code F11.1). The damage may be physical (e.g. in the cases of hepatitis from the self-administration of injected psychoactive substances) or mental.

A pattern of substance use that increases the risk of harmful consequences for the user and fetus.

A condition that follows the administration or consumption of a psychoactive substance and results in disturbances in the level of consciousness, cognition, perception, judgement, affect, or behaviour, or other psychophysiological functions and responses.

When a neonate shows signs of withdrawal from exposure to psychotropic substances in utero, this is referred to as neonatal abstinence or neonatal withdrawal.

Also referred to as opioid agonist maintenance treatment, or opioid substitution treatment. Examples of opioid maintenance therapies are methadone and buprenorphine maintenance treatment. Maintenance treatment can last from several months to more than 20 years, and is often accompanied by other treatment (e.g. psychosocial treatment).

Any non-pharmacological intervention carried out in a therapeutic context at an individual, family or group level. Psychosocial interventions range from structured, professionally administered psychological interventions (e.g. cognitive behaviour therapy or insight oriented psychotherapy) to non-professional psychological and social interventions (e.g. self-help groups and non-pharmacological interventions from traditional healers, as well as accommodation, financial support, legal support, information and outreach).

The concept of “substance use disorders” includes both the dependence syndrome and the harmful use of psychoactive substances such as alcohol, cannabis, amphetamine-type stimulants (ATS), cocaine, opioids and benzodiazepines.

Substances that vaporize at ambient temperatures. Volatile substances that are inhaled for psychoactive effects (also called inhalants) include the organic solvents present in many domestic and industrial products (such as glue, aerosol, paints, industrial solvents, lacquer thinners, gasoline and cleaning fluids) and the aliphatic nitrites such as amyl nitrite.

A group of symptoms of variable clustering and degree of severity that occur on cessation or reduction of use of a psychoactive substance that has been taken repeatedly, usually for a prolonged period or in high doses (ICD-10 code F1x.3). The onset and course of withdrawal syndrome are time-limited and relate to the type of substance and dose being taken immediately before cessation or reduction of use. Typically, the features of withdrawal syndrome are the opposite of acute intoxication.