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Psychoactive Drugs Tobacco, Alcohol, and Illicit Substances


Glossary over Psychoactive Drugs


The term alcohol refers to a family of chemicals that occur widely in nature and are mass-produced for use in antifreezes, fuels and some manufacturing processes.

Alcohol is commonly used to refer to alcohol-containing drinks such as wine, beer and spirits. In this case the alcohol, ethanol, has been produced by a process called fermentation. Consumption of excessive amounts of alcohol can lead to drunkenness and may be harmful to health. (Source: GreenFacts)

Alcohol dependence

A chronic disease characterized by a strong craving for alcohol, a constant or periodic reliance on use of alcohol despite adverse consequences, the inability to limit drinking, physical illness when drinking is stopped, and the need for increasing amounts of alcohol to feel its effects. (Source: NIH Understanding Alcohol glossary   )

Amino acid(s)

An amino acid molecule has the general formula NH2CHRCOOH, where "R" is any one of a number of side groups. Amino acids are building blocks (small molecules that link together to form long chains) of proteins.

There are 20 amino acids found in proteins, called primary amino acids. Non-essential amino acids are those made by the human body, while essential amino acids are only obtained from protein in the foods that we eat. (Source: GreenFacts)



Amphetamines are man-made stimulant drugs.

Their effects usually last for several hours and include stimulation of the central nervous system, a sense of well-being and higher energy, a release of social inhibitions, and feelings of cleverness, competence and power. Effects are very much like an adrenalin rush, with breathing and heart rate increasing. The appetite is also suppressed, the body's temperature increases, the pupils become dilated, and there is an increased risk of dehydration.

They have been used as medicines for instance for treating Attention-Deficit Hyperactivity Disorder (ADHD) or narcolepsy. They have also been used as performance-enhancing drug, for instance by athletes, pilots, and truck drivers.

They have a bitter taste and usually come as a white, greyish white, pale pink or yellow powder, and sometimes as a brightly coloured tablet.

Amphetamines can be snorted, swallowed, injected, dissolved in a drink or smoked. (Source: GreenFacts, based on A to Z of Drugs  )



A protein produced by the body's immune system that recognizes and helps fight infections and other foreign substances in the body. (Source: Gift of a Lifetime Glossary  )


Any one of a group of diseases that occur when cells in the body become abnormal and have the potential to spread and establish growth in nearby tissues and other parts of the body (malignancy). (Source: GreenFacts )



A generic term for 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.

Cannabis can be rolled with tobacco in a spliff or joint, smoked on its own in a pipe or bong, or eaten as part of a cake or cookie.

Cannabis intoxication produces a feeling of euphoria, lightness of the limbs, and often social withdrawal. It impairs driving and the performance of other complex, skilled activities; it impairs immediate recall, attention span, reaction time, learning ability, motor co-ordination, depth perception, peripheral vision, time sense (the individual typically has a sensation of slowed time), and signal detection. Other signs of intoxication may include excessive anxiety, suspiciousness or paranoid ideas in some and euphoria or apathy in others, impaired judgement, bloodshot eyes, increased appetite, dry mouth, abnormally rapid heart rate, as well a feeling of tiredness and lack of energy.

Although it is mostly quite mild, some forms of cannabis such as skunk are very strong and smokers can have a hallucinogenic reaction.

There are reports of cannabis use precipitating a relapse in schizophrenia. Acute anxiety and panic states and acute delusional states have been reported with cannabis intoxication; they usually remit within several days. (Source: GreenFacts, based on WHO Lexicon of alcohol and drug terms  )



The basic subunit of any living organism; the simplest unit that can exist as an independent living system. There are many different types of cells in complex organisms such as humans, each with specific characteristics. (Source: GreenFacts)



Occurring over a long period of time, either continuously or intermittently; used to describe ongoing exposures and effects that develop only after a long exposure. (Source: US EPA Thesaurus  )

Chronic exposure

Contact with a substance that occurs over a long time (more than 1 year [for humans]). (Source: ATSDR Glossary of Terms  )


A condition in which the liver is damaged as a result of infection or by certain substances such as alcohol and some medicines.

The damaged liver cells are replaced by scar tissue [the body tissue, usually stronger than the original tissue, remaining after a wound has healed] and the liver becomes hard and filled with fat. This prevents the liver from properly digesting food, metabolizing drugs and making proteins and can result in liver failure and death. (Source: GreenFacts)


Cocaine is a very strong stimulant drug affecting the nervous system.

Cocaine is extracted from the leaves of the coca plant found in South America and comes in the form of a white powder. In this form, cocaine can be snorted up the nose, tasted on the gums, or dissolved and injected.

Cocaine users feel – for about half an hour – a sense of well-being, confidence and alertness, and they are left with a craving for more, as well as a feeling of indifference. Users also experience dilated pupils, a rise in body temperature, and increased heart rate and blood pressure, as well as the depression and tiredness of the comedown. (Source: GreenFacts, based on A to Z of Drugs  )



Depressants are substances that [diminish] the activity of the central nervous system.

Depressants are often referred to as "downers" because of their sedative, hypnotic, and tranquilizing effects.

There are both legal and illegal depressants. Alcohol is the most common legal depressant. Other depressants that are legal are often prescribed medications used to induce sleep, relieve stress, and subdue anxiety. (Source:   Depressants   )



Depression is a mental condition affecting an individual’s mood.

It is characterized by a range of negative feelings such as sadness, loneliness, despair, low self-esteem and guilt.

A depressed person may lose interest in many aspects of life and no longer find pleasure in activities and relationships. (Source: GreenFacts)

Disability-adjusted life years (DALYs)

A method of calculating the global or world-wide health impact of a disease or the global disease burden (GDB) in terms of the reported or estimated cases of premature death, disability and days of infirmity due to illness from a specific disease or condition. (Source: UN Atlas of the Oceans
GESAMP Glossary  )



Dopamine is a chemical substance produced in the body to transmit signals between nerve cells. It is found in parts of the brain responsible for the regulation of movement, balance and walking as well as those involved in memory and learning.



The amount of a substance to which a person is exposed over some time period. Dose is a measurement of exposure. Dose is often expressed as milligram (amount) per kilogram (a measure of body weight) per day (a measure of time) when people eat or drink contaminated water, food, or soil. In general, the greater the dose, the greater the likelihood of an effect. An "exposure dose" is how much of a substance is encountered in the environment. An "absorbed dose" is the amount of a substance that actually got into the body through the eyes, skin, stomach, intestines, or lungs. (Source: ATSDR Glossary of Terms  )


Man-made stimulant psychoactive drug that combines the effects of amphetamines and hallucinogens, such as LSD.

Following intake, users commonly feel an initial rush of adrenaline, followed by a combination of feeling energetic but calm. Colour, sound, and emotions can seem more intense. Users can also experience nausea, as well as an increased heart rate. In some cases, the jaw will tightens, and the mouth and throat become dry as the user starts to sweat more

Ecstasy usually comes in the form of different coloured tablets and capsules, which are swallowed, but it can also be crushed and snorted, or smoked. (Source: GreenFacts, based on; A to Z of Drugs   )



A protein that encourages a biochemical reaction, usually speeding it up. Organisms could not function if they had no enzymes. (Source: NHGRI NHGRI Talking Glossary of Genetic Terms  )

Gamma-aminobutyric acid (GABA)

A chemical messenger in the brain, spinal cord, heart, lungs, and kidneys, which sends messages telling the body to slow down. GABA is the primary inhibitory neurotransmitter in the brain. (Source: Glossary   )


The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a specific protein. (Source: NHGRI Talking Glossary of Genetic Terms  )

Genetic screening

Test performed on a population group to identify individuals at high risk of having or passing on a specific genetic disorder. (Source: GreenFacts, based on Human Genome Project Information Glossary   )


Hallucinogens are chemical agents that induce alterations in perception, thinking, and feeling. Examples include LSD and PCP.

Effects are noted within 20-30 minutes of ingestion and include dilatation of the pupils, blood pressure elevation, abnormally rapid heart rate, involuntary trembling or quivering, overactive reflexes, and the psychedelic phase (consisting of euphoria or mixed mood changes, visual illusions and altered perceptions, a blurring of boundaries between self and non-self, and often a feeling of unity with the cosmos).

In addition to persistent or recurrent hallucinations that are regularly produced, adverse effects of hallucinogens are frequent and include bad trips, post-hallucinogen perception disorder or flashbacks, delusional disorder (the individual becomes convinced that the perceptual distortions experienced correspond with reality), and affective or mood disorder, which consist of anxiety, depression, or mania (typically, the individual feels that he or she can never be normal again and expresses concern about brain damage as a result of taking the drug). (Source: GreenFacts, based on WHO Lexicon of alcohol and drug terms  )



Inflammation of the liver caused by viruses (viral hepatitis) or by chronic exposure to medicines or toxins such as alcohol.

Symptoms include jaundice (yellowing of the skin caused by the buildup of bile pigments in the body), fever, appetite loss and gastrointestinal upset. (Source: GreenFacts)



Pain-killing drug made from the chemical morphine, which is extracted from the dried latex of the opium poppy. Heroin is extremely fast acting, and within a few seconds a small dose will give the user an instant feeling of well-being. Much larger doses can make users relaxed and drowsy.

Pure heroin is a white powder, but street heroin comes as a brownish-white powder that can be smoked, snorted or dissolved and injected. (Source: GreenFacts, based on A to Z of Drugs )


Institute for the encouragement of Scientific Research and Innovation of Brussels

"ISRIB, which was instituted by the Brussels decree of 26 June 2003, began its activites on 1st July 2004.

The mission of the Institute is to promote, support and valorize scientific research and technological innovation in the Brussels-Capital Region.

This task consists principally in funding research projects undertaken within the companies, the universities and the higher education institutes located in the Region." (Source: ISRIB website )

LSD (lysergic acid diethylamide)

Powerful hallucinogenic drug that is derived from a fungus found growing on rye and other wild grasses.

LSD is actually a white powder, but is sold on the streets in liquid form, or soaked into paper sheets. Only small amounts of the drug are needed to get an effect, so it can also be absorbed into sugar cubes and then swallowed.

The effects of LSD, known as a trip, are dependant on the individual, how much is taken, how the user feels and the situation they are in. Trips usually begin about half an hour after taking the drug, peak up to six hours later and then eventually fade after about twelve hours. No trip is ever the same.

Because it is an hallucinogenic drug it changes the way the mind perceives things, so sense of movement can be impaired and time may seem to speed up or slow down. Colours, sounds and surroundings may become distorted, and flashbacks, or feelings of the mind being separated from the body are also commonplace. (Source: GreenFacts, based on A to Z of Drugs  )


Magnetic Resonance Imaging (MRI)

A technique that uses a strong circular magnet in combination with pulses of radio waves to produce detailed images of internal organs. MRI is especially useful for imaging spine, joints, and inside bones and also soft tissue such as the brain.

Physicians can use MRI to see for instance the difference between normal and diseased brain tissue or which parts of the brain are active when you perform certain tasks or feel certain emotions and sensations.

MRI is one of several Nuclear Magnetic Resonance techniques. (Source: GreenFacts, based on Institute of Physics Inside story: MRI scans   )


Mesolimbic dopamine pathway

Brain circuit that is activated by rewarding stimuli, e.g., food, sex and by addictive psychoactive drugs, such as cocaine , amphetamines , and alcohol . The intense feeling from activation of the reward or pleasure experienced previously leads to a desire for, or repetition of, the behaviour.

In chronic substance users this can lead to chronic and intense cravings which may be activated by anticipatory dopamine release in response to cues (e.g. drug use implements).

The mesolimbic dopamine pathway comprises the ventral tegmental area (VTA), nucleus accumbens (Nac) and the prefrontal cortex. (Source: GreenFacts, based on Alcohol & Other Drugs A to Z Drug Glossary   )


The conversion or breakdown of a substance from one form to another by an enzyme. (Source: GreenFacts, based on ATSDR Glossary of Terms )



A substance that is the product of biological changes to a chemical. (Source: US EPA Glossary  )



A natural compound produced by the opium poppy and the main active agent in opium.

Morphine is a powerful pain-killing drug. (Source: GreenFacts )

Nervous system

The nervous system is a complex, sophisticated system that regulates and coordinates body activities.

It is made up of:

  • the central nervous system, consisting of the brain and spinal cord, and
  • the peripheral nervous system which includes, the eyes, the ears, the sensory organs of taste and smell, as well as the sensory receptors located in the skin, joints, muscles, and other parts of the body.

Neurons are the nerve cells that make up the central nervous system.

This unique type of cell found in the brain that receives and conducts electric imulses, processing and transmitting information

A neuron consists of a cell body containing the nucleus, a single axon which sends messages by conveying electrical signals to other neurons, and a host of dendrites which deliver incoming signals. (Source: GreenFacts)



Chemical responsible for the transfer of information along the nervous system. (Source: IPCS )



Class of drugs (e.g., heroin, codeine, methadone) that are derived from the opium poppy plant, contain opium, or are produced synthetically and have opium-like effects. Opioid drugs relieve pain, dull the senses, and induce sleep. (Source: San Francisco AIDS Foundation Glossary   )


Phencyclidine (PCP)

This drug is considered a hallucinogen but it can also relieve pain or act as a stimulant.

PCP is available in a number of forms. It can be a pure, white crystal-like powder, a tablet or a capsule. It can be swallowed, smoked, sniffed, or injected. PCP is sometimes sprinkled on marijuana or parsley and smoked.

Effects begin within 5 minutes and peak at about 30 minutes. At first, the user feels euphoria, body warmth, and tingling, floating sensations, and a feeling of calm isolation. Auditory and visual hallucinations may appear, as well as altered body image, distorted perceptions of space and time, delusions, and disorganization of thought.

Accompanying symptoms include hypertension, rapid involuntary movement of the eyes, loss of muscular coordination, slurred speech, grimacing, profuse sweating, overactive reflexes, diminished responsiveness to pain, muscle rigidity, abnormally high body temperature, abnormally acute hearing, and seizures.

Effects usually last for 4-6 hours, although residual effects may take several days or longer to clear. During the immediate recovery period there may be self-destructive or violent behaviour. (Source: GreenFacts, based on WHO Lexicon of alcohol and drug terms )



An inactive substance or treatment that looks the same as, and is given the same way as, an active drug or treatment being tested. The effects of the active drug or treatment are compared to the effects of the placebo. (Source: NCI dictionary  )


A group or number of people living within a specified area or sharing similar characteristics (such as occupation or age). (Source: ATSDR Glossary of Terms  )



A molecule on the surface of a cell that serves as a recognition or binding site for antigens, antibodies or other cellular or immuniologic components. (Source: NIAID HIV vaccine Glossary   )


Generic term for a group of drugs that are central nervous system depressants with the capacity of relieving anxiety and inducing calmness and sleep.

All sedatives/hypnotics may impair concentration, memory, and coordination. Other frequent effects are hangover, slurred speech, incoordination, unsteady gait, drowsiness, dry mouth, decreased gastrointestinal motility , and changes in mood. A reaction of excitement or rage may be produced occasionally.

Patients treated over a long period can become psychologically and physically dependent on the drug even if they never exceed the prescribed dose.

Withdrawal reactions can be severe and may occur after no more than several weeks of moderate use.

Long-term sedative/hypnotic abuse is likely to produce impairments in memory, verbal and nonverbal learning, speed, and coordination that last long after detoxification and, in some, result in a permanent memory disorders.

At high doses or when they are abused, many of these drugs can even cause unconsciousness and death. (Source: GreenFacts, based on WHO Lexicon of alcohol and drug terms   )


Chemical messenger [(neurotransmitter)] in the brain that affects emotions, behavior, and thought (Source: University of Maryland Medical Center Women’s Health Glossary   )


Stimulants are drugs that stimulate the activity of the central nervous system.

Stimulants are often referred to as "uppers" because they increase or speed up mental and physical processes in the body. Some are prescribed medically to increase alertness and physical activity.

Stimulants include nicotine (found in tobacco products), caffeine, amphetamines, ecstasy, and cocaine.

Stimulants can give rise to symptoms suggestive of intoxication, including abnormally rapid heart rate, dilatation of the pupils, elevated blood pressure, overactive reflexes, sweating, chills, nausea or vomiting, and abnormal behaviour such as fighting, hypervigilance, agitation, feelings of superiority, and impaired judgement. Chronic misuse commonly induces personality and behaviour changes such as impulsivity, aggressivity, irritability, and suspiciousness.

Cessation of intake after prolonged or heavy use may produce a withdrawal syndrome, with depressed mood, fatigue, sleep disturbance, and increased dreaming. (Source: GreenFacts, based on WHO Lexicon of alcohol and drug terms   )



Anything capable of evoking a response in an organism. Examples of stimuli include irritants, sights, sounds, heat, cold, smells, or other sensations. (Source: Medline Plus Medical Encyclopedia   )


The likelihood of producing a significantly larger-than-average response to a specified exposure to a substance.



Measures taken to treat a physical or mental disease.

First-line therapy is the first type of therapy given for a condition or disease.

Second-line therapy is the treatment that is given when initial treatment (first-line therapy) doesn't work, or stops working. (Source: based on St Jude Hospital Medical Terminology & Drug Database )

US National Institute on Drug Abuse

"NIDA's mission is to lead the Nation in bringing the power of science to bear on drug abuse and addiction.

Recent scientific advances have revolutionized our understanding of drug abuse and addiction. The majority of these advances, which have dramatic implications for how to best prevent and treat addiction, have been supported by the National Institute on Drug Abuse (NIDA).

NIDA supports most of the world's research on the health aspects of drug abuse and addiction. NIDA supported science addresses the most fundamental and essential questions about drug abuse, ranging from the molecule to managed care, and from DNA to community outreach research." (Source: NIDA website )

US National Institutes of Health

"The National Institutes of Health (NIH), a part of the U.S. Department of Health and Human Services, is the primary Federal agency for conducting and supporting medical research. Helping to lead the way toward important medical discoveries that improve people’s health and save lives, NIH scientists investigate ways to prevent disease as well as the causes, treatments, and even cures for common and rare diseases. Composed of 27 Institutes and Centers, the NIH provides leadership and financial support to researchers in every state and throughout the world." (Source: NIH website  )

Volatile solvents (as a drug)

Volatile solvents are liquids that vaporize at room temperature.

These organic solvents can be inhaled for psychoactive effects and are present in many domestic and industrial products such as glue, aerosol, paints, industrial solvents, lacquer thinners, gasoline, and cleaning fluids.

Some substances are directly toxic to the liver, kidney, or heart, and some produce peripheral neuropathy (nerve damage usually affecting the feet and legs) or progressive brain degeneration.

The most frequent users of these substances are young adolescents and street children. The user typically soaks a rag with inhalant and places it over the mouth and nose, or puts the inhalant in a paper or plastic bag which is then put over the face.

Signs of intoxication include agressiveness, lethargy, impaired movement, euphoria, impaired judgement, dizziness, rapid involuntary movement of the eyes, blurred vision or double vision (diplopia), slurred speech, tremors, unsteady gait, overactive reflexes, muscle weakness, stupor, or coma. (Source: GreenFacts, based on WHO Lexicon of alcohol and drug terms )


Vulnerability (in health science)

The likelihood of being unusually severely affected by a substance either as a result of susceptibility to the effects of these substances or as a result of a greater than average [exposure]. (Source: WHO Europe  Answers to follow-up questions from CAFE )


Withdrawal refers to the physical and mental symptoms drug-dependent people experience when they stop taking the drug they depend upon or when they drastically reduce its use. (Source: GreenFacts)


World Health Organization

"The World Health Organization  (WHO) is the directing and coordinating authority on international health within the United Nations’ system. WHO experts produce health guidelines and standards, and help countries to address public health issues. WHO also supports and promotes health research. Through WHO, governments can jointly tackle global health problems and improve people’s well-being.

193 countries and two associate members are WHO’s membership. They meet every year at the World Health Assembly in Geneva to set policy for the Organization, approve the Organization’s budget, and every five years, to appoint the Director-General. Their work is supported by the 34-member Executive Board, which is elected by the Health Assembly. Six regional committees focus on health matters of a regional nature."

WHO's scientific publications are widely recognized as a reference source.

The WHO has a number of regional offices which address the specific issues of those regions.

WHO World Regional Offices
  WHO African Region  (46 countries)
  WHO European Region  (53 countries)
  WHO Eastern Mediterranean Region  (21 countries)
  WHO Region of the Americas  (35 countries)
  WHO South-East Asia Region  (11 countries)
  WHO Western Pacific Region  (27 countries)

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