Drug addiction and drug abuse, chronic or habitual use of any chemical substance to alter states of body or mind for other than medically warranted purposes. Among the drugs with potential for abuse are NARCOTICS, including morphine, opium, heroin, and methadone; depressants such as ALCOHOL, BARBITURATES, and sedatives; stimulants such as COCAINE (see also CRACK) and AMPHETAMINES; HALLUCINOGENIC DRUGS; and MARIJUANA. Nicotine and CAFFEINE can also be abused, and ANABOLIC STEROIDS and HUMAN GROWTH HORMONE are often abused by athletes and bodybuilders seeking to increase muscle mass. An individual is said to be addicted if a physical dependence on a given drug develops and if withdrawal symptoms are experienced when the drug is discontinued or its dose decreased. True physical addiction is known to occur with the narcotics and depressants; psychological dependence, with or without physical symptoms, can develop with many other drugs, such as TRANQUILIZERS. The hallucinogens can also cause traumatic experiences and trigger psychotic reactions, including paranoia. Treatment for drug addiction includes METHADONE programs and participation in therapeutic communities (e.g., Synanon and Phoenix House) with other addicts who are giving up drugs (see also ALCOHOLISM). The question of what constitutes drug abuse depends on the cultural and social context. In some countries, narcotic use in the form of opium smoking is common and not considered a serious drug problem; in others, hashish or related compounds are widely used. In most industrialized nations, however, the use of many of these drugs is illegal and associated with criminal behavior.

NARCOTIC

narcotic (när-kòt´îk), group of drugs with potent analgesic effects, associated with alteration of mood and behavior. The chief narcotic drugs are OPIUM, CODEINE, MORPHINE, and the morphine derivative HEROIN. Narcotics are thought to act by mimicking and/or enhancing the activity of ENDORPHINS, proteins produced by the brain and believed to modulate pain and other nervous system functions. Narcotics are valuable in numbing the senses, alleviating pain, inducing sleep, and relieving diarrhea. Common side effects include nausea, vomiting, and allergic reactions. In large doses, narcotics can cause respiratory depression, COMA, and death. All narcotics are addictive; synthetic narcotics such as meperidine and METHADONE tend to be less addicting and possess fewer side effects, but they are also less potent. (See DRUG ADDICTION AND DRUG ABUSE).

ALCOHOL

alcohol (àl´ke-hôl´), any of a class of organic compounds with the general formula R-OH, where R is an alkyl group made up of carbon and hydrogen and -OH is one or more hydroxyl groups, each made up of one atom of oxygen and one of hydrogen. Although the term alcohol ordinarily refers to ETHANOL, the alcohol in alcoholic beverages, the class of alcohols also includes METHANOL and the amyl, butyl, and propyl alcohols, all with one hydroxyl group; the glycols, with two hydroxyl groups; and glycerol, with three. Many of the characteristic properties and reactions of alcohols are due to the polarity, or unequal distribution, of electric charges in the C-O-H portion of the molecule.

BARBITURATE

barbiturate (bär-bîch´er-ît), any depressant drug derived from barbituric acid. In low doses, barbiturates have a tranquilizing effect. Increased doses are hypnotic or sleep-inducing, and still larger doses act as anticonvulsants and anesthetics. Barbiturates were widely used as SLEEPING PILLS; such use may lead to psychological dependency, physiological tolerance, and even death by overdose (see DRUG ADDICTION AND DRUG ABUSE). Barbiturates do not relieve pain.

COCAINE

cocaine (ko-kân´), ALKALOID drug derived from COCA leaves, producing euphoria, hallucinations, and temporary increases in physical energy. Prolonged use can cause nervous-system aberrations (including delusions), general physical deterioration, weight loss, and addiction (see DRUG ADDICTION AND DRUG ABUSE). Withdrawal from the drug can produce severe depression. See also CRACK.

CRACK

crack, a form of COCAINE. A less expensive, more potent, smokable form of the drug, it is the most addictive of abused substances. The drug's availability has greatly increased the number of addicts, resulting in major law enforcement problems in Western countries. See also DRUG ADDICTION AND DRUG ABUSE.

AMPHETAMINE

amphetamine (àm-fèt´e-mên´), any of a class of powerful drugs that act as stimulants on the central nervous system. Popularly known as "bennies," "speed," or "uppers," amphetamines enhance mental alertness and the ability to concentrate; cause wakefulness, talkativeness, and euphoria; and temporarily reverse the effects of fatigue. They have been used to treat obesity, narcolepsy and minimal brain dysfunction. Amphetamines can produce insomnia, hyperactivity, and irritability, as well as such severe systemic disorders as cardiac irregularities, elevated blood pressure, and gastric disturbances. The drugs are addictive and easily abused; addiction can result in psychosis or death from over exhaustion or cardiac arrest (see DRUG ADDICTION AND DRUG ABUSE).

HALLUCINOGENIC

hallucinogenic drug, ALKALOID substance that alters consciousness; also called psychotomimetic, or, popularly, psychedelic or mind-expanding drug. Hallucinogens include mescaline, or PEYOTE; psilocin and psilocybin, from the mushrooms Psilocybe mexicana and Stropharia cubensis; LSD (lysergic acid diethylamide); BELLADONNA; and MANDRAKE. MARIJUANA has hallucinogenic properties but is pharmacologically distinct. Hallucinogens have been used by primitive societies in both the Old and New Worlds to facilitate meditation, cure illness, placate evil spirits, and enhance mystical and magical powers. They produce a wide range of effects, from pleasant to very disturbing, depending on dosage, potency, and the personality and environment of the drug taker. Effects include altered perception of time and space and of the color, detail, and size of objects; also the experience of imaginary conversations, music, odors, tastes, and other sensations. Hallucinogens are not physically habit-forming, but tolerance, i.e., the need to take increased quantities to induce the original effect, may develop.

MARIJUANA

marijuana (màr´e-wä´ne) or marihuana, relatively mild but, addictive drug with hallucinogenic properties, obtained from the flowering tops, stems, and leaves of the HEMP plant. Resins found on the surface of the female plant are used to prepare the most potent form of marijuana, hashish. The primary active substance is tetrahydrocannabinol (THC). Marijuana produces a dreamy, euphoric state of altered consciousness, with feelings of detachment and gaiety. The appetite is usually enhanced, while the sex drive may increase or decrease. Adverse reactions are relatively rare, and most can be attributed to adulterants frequently found in marijuana preparations. Marijuana has been used experimentally to reduce nausea from cancer CHEMOTHERAPY and in the treatment of GLAUCOMA, but in 1992 the Drug Enforcement Administration declined to reclassify marijuana so that it could be prescribed by doctors. Marinol, a synthetic form of THC, is approved for use in reducing the nausea caused by chemotherapy. In the U.S. there were a number of successful efforts, especially in the 1970s, to reduce criminal penalties for possession and use of marijuana, but many of the resulting laws have since been modified or repealed.

CAFFEINE

caffeine (kà-fên´), odorless, slightly bitter ALKALOID found in coffee, tea, COLA nuts, MATÉ, and cocoa (see CACAO). In moderation, caffeine is a mild stimulant that increases urination and the heart rate and rhythm. Excessive intake can cause restlessness, insomnia, heart irregularities, and delirium.

ANABOLIC STEROID

anabolic steroid or androgenic steroid, any of a group of synthetic derivatives of TESTOSTERONE that promote muscle and bone growth. Used therapeutically to treat chronic debilitating diseases, anabolic steroids have also been used by bodybuilders and athletes seeking increased muscle mass and enhanced strength and stamina. Such use is banned by the International Olympic Committee and other governing bodies in sports, and in 1988 a federal law made it illegal to distribute anabolic steroids for nontherapeutic uses. Abuse of anabolic steroids may lead to increased aggressiveness, irritability, and other disruptive behavioral effects, including symptoms characteristic of drug addiction; long term effects are not known.

HUMAN GROWTH HORMONE

human growth hormone (HGH) or somatotropin, glycoprotein hormone released by the anterior PITUITARY GLAND that is necessary for normal skeletal growth in humans (see PROTEIN). Evidence suggests that the secretion of HGH is regulated by the release of certain peptides by the HYPOTHALAMUS of the brain. One such substance, called somatostatin, has been shown to inhibit the secretion of HGH. HGH is known to act on many aspects of cellular metabolism, but its most obvious effect is the stimulation of the growth of cartilage and bone in children. An HGH deficiency before puberty results in pituitary dwarfism; an excess results in gigantism. Excess HGH after puberty has little effect on skeletal growth but results in a disease known as acromegaly. Pituitary dwarfism can be treated by injections of synthetic growth hormone produced by GENETIC ENGINEERING in bacteria. HGH is also used illegally by bodybuilders and athletes to increase muscle mass.

TRANQUILIZER

tranquilizer (tràng´kwe-lìz´er), drug whose action on the central nervous system relieves emotional agitation. Antipsychotic drugs, or major tranquilizers, ease the symptoms of psychotic states, including agitation, delusions, and anxiety. These drugs include chlorpromazine (Thorazine), the first agent to be widely applied to mental disorders and still the standard drug. ANTIANXIETY DRUGS, or minor tranquilizers, are prescribed to relieve anxiety and tension. See also LITHIUM.

METHADONE

methadone, synthetic NARCOTIC, similar in effect to MORPHINE, used primarily in the treatment of narcotic drug addiction. Given to addicts, it blocks the euphoric action of HEROIN without itself causing euphoria and causes less severe and hazardous withdrawal symptoms than other narcotic drugs (although critics of methadone therapy point out that methadone patients are still addicts). Methadone is also used as an ANALGESIC, especially in patients who are terminally ill.

ALCOHOLISM

alcoholism (àl´ke-hô´lîz´em), chronic illness characterized by the habitual consumption of alcohol to a degree that interferes with physical or mental health, or with normal social or occupational behavior. A widespread health problem, it produces both physical and psychological addiction (see DRUG ADDICTION AND DRUG ABUSE). Alcohol is a central nervous system depressant that reduces anxiety, inhibition, and feelings of guilt; lowers alertness; impairs perception, judgment, and muscular coordination; and, in high doses, can cause unconsciousness and even death. Long-term alcoholism damages the brain, liver (see CIRRHOSIS), heart, and other organs. Symptoms of alcohol withdrawal can range from a simple hangover to severe delirium tremens (a condition characterized by deliriousness, violent trembling, hallucinations, and seizures). Treatment includes use of disulfiram (Antabuse), a drug that produces discomfort if alcohol is consumed; anti-anxiety drugs to suppress withdrawal symptoms; psychological counseling; and support from groups such as ALCOHOLICS ANONYMOUS.