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Health and
Fitness
The
Human Brain
Mind and Drug Addiction
The
nervous system is the most complex and highly organized of all biological
systems. It is fascinating as to how the billions of nerve cells (neurons)
work together to control various functions of organs and systems in the
body. Precisely, it is the nervous system which enables the organism to
adapt to a constantly changing external environment. This phenomenon is
termed as homeostasis. The complete working unit involved in homeostasis
consists of the central nervous system (CNS) and the peripheral nervous
system including the autonomic nervous system (ANS).
The cerebral cortex contains about 9 million nerve cells, and is
responsible for consciousness
and co-ordination of external and internal stimuli. The highly organized
cerebrum delineates
humans from all other living organisms. Removal of the entire cerebrum in
the frog produces
no behavioral changes. Whereas, the human being becomes totally blind,
extensively
paralyzed, and soon dies. Concerning human behavior, the most important
regions of the
brain involved are the limbic system and the reticular formation. The
limbic system controls
emotions involving both mental and physical elements. The memory process,
learning, and
motivational aspects of behavior are all governed by the limbic system.
The reticular
formation is the "bridge" portion of the CNS which controls the inflow and
out flow of impulses,
and is responsible for alertness, arousal, sleep and attention,
maintaining a state of
consciousness in man. The activity and function of the nervous system can
be modified by a
wide range of chemicals or drugs having either a direct effect on nerve
cells, or by producing
changes in the levels of chemical transmitters (neurotransmitters) in the
system.
In ancient times agents given to patients with mental disorders were
limited to herbal potions
that consisted mostly of inactive ingredients. Major advances were made in
the early 1950s
with the introduction of reserpine and chlorpromazine. These two compounds
provided a
chemical basis for the treatment of psychosis, a major mental disorder.
Later, a number
of drugs followed which altered behavior, and today the most effective
tool available to
control mental disorders is appropriate drug therapy. This has reduced the
period of
hospitalization for the mentally ill.
Drugs which modify behavior are termed as psychopharmacological agents and
include:
(a) antipsychotics; (b) antidepressants; (c) antimanics; and (d)
anti-anxiety agents. Lastly the
psychotomimetics or hallucinogens, which have no medical uses, but are
dangerous drugs of
abuse.
Schizophrenia is a major mental disorder, which ruins the most useful
years of one's life.
"Cures" are rare. The antipsychotics have a profound effect on the ANS,
hypothalamus, and
the reticular formation. These drugs have a wide margin of safety, but
adverse reactions
include lethargy, involuntary muscle movements, endocrinal disorders, and
depression of
the bone marrow.
The antidepressants (psychic energizers) have been an outstanding success
in modern
psychopharmacology. They are used to treat depression, which is an
affective disorder
afflicting many individuals. Depression is the most frequently
unrecognized emotional
disorder, which can be effectively controlled by appropriate therapy.
The anti anxiety agents, which include the benzodizepines, are used to
treat anxiety neuroses
by producing calmness and muscle relaxation. In addition they produce
euphoria, i.e., a false
feeling of well being. These drugs produce tolerance, psychological and
physical dependence.
Thus, they are dangerous addictive drugs, very likely to be misused,
particularly by the youth,
more so in this modern competitive and stressful world, with a hectic
lifestyle.
Many drugs today are taken by man for the pleasant effects they produce.
Such drug use
leads to serious socioeconomic problems like drug abuse or drug
dependence. The long list
includes alcohol, tobacco, morphine, opium, codeine, heroin, brown sugar,
smack, barbiturates, methaqualone, diazepam, alprazolam, amphetamine,
cocaine, and hallucinogens like LSD, mescaline and cannabis.
Classically
drug addiction (dependence) is characterized by: (i) an overpowering
desire to continue taking the drug, and to obtain it by any means, i.e.,
habituation; (ii) a tendency to increase the amount taken, i.e.,
tolerance; and (iii) a psychic, and at times physical dependence on the
effects of the drug. In physical dependence there is a biochemical and
physiological adaptation of the tissues to the new chemical environment
following the repeated use of the drug. Thus, upon withdrawal of the drug
a serious abnormal cellular response is produced known as the
withdrawal syndrome, which is different for each drug, and may be life
threatening.
Let us consider how drug abuse begins?
Usually a person tries a drug, likes what happens, and continues to use it
a few more times, and ultimately becomes addicted to it. Later, their
continuous use produces harmful effects, a.go., alcoholism produces
progressive deterioration of physical and mental health, internal
bleeding, liver and brain damage and psychosis.
Alcohol
contaminated with methyl alcohol causes blindness; LSD can lead to
psychosis, and
dreadful thought disorders; Cannabis alters the thought process, and can
lead to birth defects
when consumed by pregnant women; Chronic use of tobacco is linked to
coronary heart
disease and lung cancer; and so on. De-addiction of the patient is
difficult, and needs
hospitalization, psychotherapy, supportive treatment, and rehabilitation.
All these measures
are time consuming, tedious, and expensive to afford.
In conclusion, today many potent and effective drugs are available, and
can be effectively
employed in the treatment of the mentally ill. But some of them may be
misused by man to
enjoy the pleasant effects they produce, leading to drug addiction.
Control of addiction
warrants serious attention of the medical profession, social welfare
organizations, and the
government which must clamp a stricter drug control in the country.
– Dr. Frank S.K. Barar
March 13, 2005
Dr. Frank S.K. Barar retired
as Sr. Professor and Head, Dept. of Pharmacology, SMS Medical College,
Jaipur-302004 in November 1990. With over 30 years of teaching experience
he received the Dr. B.C. Roy National Award, 1988 in the category of
Eminent Teacher. He has authored two books in Pharmacology titled as
"Essentials of Pharmacotherapeutics", (S. Chand), and Textbook of
Pharmacology" (Interprint). Currently he practices Internal Medicine at a
charitable clinic at Jodhpur.
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