DRUG
MISUSE
Drug Dependence is psychological and
sometimes physical state characterized by a compulsion to take a drug in order
to experience its psychological effects. Addiction is a severe form of
dependence usually marked by physical dependence. The latter state exists when
the drug has produced physiological changes in the body as evidenced by the
development of tolerance (when increasing amounts of the drug are needed to
achieve the same effect) and of a withdrawal syndrome after the drug's effects have
worn off. The syndrome is marked by such symptoms as nausea, diarrhea or pain;
these vary with the type of drug. Psychological dependence or habituation is
present when the compulsion to take a drug is strong even in the absence of
physical withdrawal symptoms.
Scientists often measure a drug's
potential for abuse by studies with laboratory animals. Drugs that an animal
will administer to itself repeatedly are said to have powerful reinforcing
properties and a high potential for abuse. Examples include some of the major
abused drugs—opium, alcohol, cocaine and barbiturates. Other drugs such as
marijuana and the psychoactive drugs appear to produce habituation in humans
even though they are not powerful reinforcers for
laboratory animals.
The drugs that are commonly abused,
besides substances such as alcohol and tobacco can be grouped into six classes:
the opioids, sedative-hypnotics, stimulants,
hallucinogens, cannabis and inhalants.
Opioids
The class of opioids
includes drugs derived from opium (such as morphine
and heroin) and its synthetic
substitutes (such as methadone). Medically morphine is a potent pain reliever;
indeed, it is the standard by which other pain-relieving drugs are measured. It
and other opium derivatives also suppress coughing, reduce movements of the
intestine (providing relief from diarrhea) and induce a state of psychological
indifference. Heroin a preparation synthesized from morphine was introduced in
1898 as a cough suppressant and nonaddicting substitute for morphine. The addictive
potential of heroin was soon recognized however and its use was prohibited in
many countries even in medical practice. Users report that heroin produces a
“rush” or a “high” immediately after it is taken. It also produces a state of
profound indifference and may increase energy.
Opioids produce different effects under
different circumstances. The drug taker's past experience and expectations have
some influence, as does the method of administering the drug (by injection,
ingestion, or inhalation). Symptoms of withdrawal include kicking movements in
the legs, anxiety, insomnia, nausea, sweating, cramps, vomiting, diarrhea and
fever.
During the 1970’s when scientists
isolated substances called enkephalins, naturally
occurring opiates in the brain, they discovered what many believe to be the
reason behind physical dependence on opioids—that is,
the drugs are thought to mimic the action of enkephalins.
If true, this hypothesis suggests that physical dependence on the opioids may develop in those who have a deficiency of these
natural substances.
Hallucinogens
Hallucinogens are not used medically
in most countries except occasionally in the treatment of dying patients,
people with mental illness, drug abusers and alcoholics. Among the
hallucinogens that were widely abused during the 1960’s are lysergic acid
diethylamide or LSD and mescaline, which is
derived from the peyote cactus. Although tolerance to these drugs develops
rapidly, no withdrawal syndrome is apparent when they are discontinued.
Phencyclidine or PCP known popularly by such names as
“angel dust” and “rocket fuel” has no current use among human beings but is
occasionally used by veterinary surgeons as an anesthetic and sedative for
animals. It became a common drug of abuse in the late 1970’s, partly because it
can easily be synthesized. Its effects are quite different from those of other
hallucinogens. LSD 
for example produces detachment and
euphoria, intensifies vision and often leads to a crossing of senses (colors
are “heard”, sounds are “seen”). PCP by contrast produces a sense of detachment
and a reduction in sensitivity to pain; it may also result in either triggering
or producing symptoms so like those of acute schizophrenia that even
professionals confuse the two states. The combination of this effect and
indifference to pain has sometimes resulted in bizarre thinking, occasionally
marked by violently destructive behavior.
Cannabis
The plant Cannabis sativa is the
source of both marijuana and hashish. The leaves, flowers and twigs of
the plant are crushed to produce
marijuana; its concentrated resin is hashish. Both drugs are usually smoked.
Their effects are similar: a state of relaxation, accelerated heart rate,
perceived slowing of time, and a sense of heightened hearing, taste, touch and
smell. These effects can be quite different, however, depending on the amount
of drug consumed and the circumstances under which it is taken. Marijuana and
hashish are not thought to produce psychological dependence except when taken
in large daily doses. The drugs can be dangerous, however, especially when
smoked before driving. Although the chronic effects are not yet clear,
marijuana is probably injurious to the lungs in much the same way as tobacco. A
source of concern is its regular use by children and teenagers, because the
intoxication markedly alters thinking and interferes with learning. A consensus
exists among doctors and others working with children and adolescents that use is undesirable and may interfere with psychological and
possibly physical, maturation.
Cannabis has been used as a folk
remedy for centuries, but it has no well-established medical use today.
Experimental work has been done using its active ingredient,
delta-9-tetrahydrocannabinol (THC), for treating alcoholism, seizures, pain,
the nausea produced by anticancer medications and glaucoma. Its usefulness for
glaucoma patients seems fairly certain, but its disorienting effects make its
possible employment by cancer patients more doubtful.
Inhalants
In the class of inhalants are
substances that are not usually considered drugs, such as glue, solvents, and aerosols, such as cleaning fluids. Most such substances sniffed for their psychological
effects act to depress the central nervous system. Low doses can produce slight
stimulation, but in higher amounts they cause their users to lose control or
lapse into unconsciousness. The effects, which are immediate, can last for as
long as 45 minutes. Headache, nausea, and drowsiness follow. Sniffing inhalants
can impair vision, judgment and muscle and reflex control. Permanent damage can
result from prolonged use, and death can result from sniffing highly
concentrated aerosol sprays. Although physical dependence does not seem to
occur, tolerance to some inhalants does develop. Another source of medical
concern is the widespread misuse, for their supposed aphrodisiac effect, of
so-called “poppers”—chemicals such as isoamyl nitrite
that have legitimate medical functions as blood-vessel dilators. Continued
sniffing of these substances can damage the circulatory system and have related
harmful effects.
Alcoholism is chronic and usually progressive
illness involving the excessive inappropriate ingestion of ethyl alcohol,
whether in the form of familiar alcoholic beverages or as a constituent of
other substances. Alcoholism is thought to arise from a combination of a wide
range of physiological, psychological, social and genetic factors. It is
characterized by an emotional and often physical dependence on alcohol and it
frequently leads to brain damage or early death.
Anti-alcoholism Congress in
FDC was sent as registered from
