Definition of depression
Definition of Depression
a state of sadness, decreased initiative, and introversion. Psychiatrists
differentiate between reactive and endogenous depression. Reactive depression is
caused by external events, such as the death of a loved one or some other personal
tragedy. The source of endogenous depression, however, is physiological, with a
genetic component apparently involved in at least some cases. A major depressive
episode is one in which an individual exhibits a combination of depressive symptoms
which can include loss of interest in previously enjoyed activities, feelings of
hopelessness, and suicidal thoughts for a period of over two weeks.
Normal and abnormal reactive depressions are not clearly distinguishable, differing
mainly in degree and duration. They range from neurotic reactions in which there is
no serious disturbance in thinking to psychotic reactions in which there are delusions
and other signs of loss of contact with reality.
Endogenous depression, also called melancholia, takes various forms. Agitated
depression is a syndrome characterized by depression with feelings of worthlessness
and despair, although the patient is overactive and talkative. In the condition called
bipolar disorder, depressive phases marked by lethargy and feelings of guilt and
hopelessness alternate with episodes that can include hyperactivity and inflated
Psychoanalytically, depression is held to result from guilt feelings arising from the
redirection against the self of unconscious hostility to others. Biochemically,
endogenous depression seems to be related to abnormal metabolism of the
neurotransmitters serotonin and norepinephrine in the brain. Antidepressant drugs,
often employed in conjunction with psychotherapy, have been found to be useful in
treating depression. Medications prescribed include tricyclic drugs, monoamine
oxidase (MAO) inhibitors, and serotonin specific reuptake inhibitors (SSRIs). All of
these help to maintain serotonin or norepinephrine levels in the brain's synapses.
Electroconvulsive therapy, involving the use of electrically induced seizures in a
controlled setting, also can be effective against depression.
Austin E. Grigg*
(Cited from Encyclopedia Americana in Grolier Online)
Depression is an uncomfortable mental state that may be characterized by such
adjectives as blue
, or discouraged
. In ordinary usage the word refers to a
mood state that in medicine is called dysthymia, as contrasted with the normal state,
euthymia, and the opposite state, elation. In psychiatric usage, disorders of mood are
called affective or mood disorders. Depression may be this in itself or a symptom of
another mental disorder. Normal human responses to some situations may also
include transient depressions. For example, mourning usually involves a depressed
mood, but this is considered to be an expected response to loss. (For seasonal
Major depressions occur in 10 20% of the world's population in the course of a
lifetime. Women are more often affected than men, by a two-to-one ratio, but cultural
and social rather than biological factors primarily account for this difference.
Relatives of patients with major depression seem at some higher risk of becoming
depressed, and about 2% of the population may have a chronic disorder known as a
depressive personality. (The conditions called
cyclothymic disorder, and substance-induced mood disorders also involve periods of
Depression is defined by its symptoms. The American Psychiatric Association's lists:
1. poor appetite and significant weight loss, or the reverse; 2. insomnia, or increased sleep; 3. agitation, or retardation, of movement and thought; 4. loss of interest or pleasure in usual activities or decrease in sexual
5. fatigue and loss of energy; 6. feelings of worthlessness, self-reproach, or excessive or
7. diminished ability to concentrate, or indecisiveness; and 8. recurrent thoughts of death or suicide, or suicide attempts.
Since transient emotional responses are common, these symptoms should have lasted
two to three weeks before a diagnosis of major depression is made.
Not all of these characteristics occur in each depressed individual, and some or all
may be present and the individual may still not consider himself or herself depressed.
For purposes of psychiatric treatment, a person is considered to have experienced a
major depressive episode if he or she exhibits a loss of interest or pleasure in all or
almost all usual activities and shows at least four of the above symptoms nearly every
day for at least two weeks. Professional treatment would be considered essential for
The term depression
is often modified by words that imply either some specific factor
or some chemical mechanism as the cause of the state. Thus, in psychological terms,
depressions have been considered as reactions to some loss of or separation from a
valued person or object. These are called reactive depressions (or neurotic depressions,
but that is a misnomer), as contrasted with the usually more severe depressions
without apparent cause called endogenous depressions, or those accompanied by
delusions or hallucinations and sometimes called psychotic depressions. (Melancholia
a term once used to describe all depressive states, is now applied only to these most
severe forms.) Such distinctions are not clear-cut, however, and may not be useful
when deciding on the mode of treatment of the depressed patient.
The predominant chemical, or biological, theory of depression is the so-called amine
hypothesis. Based on observations that depression can be caused by drugs that deplete
the brain of chemicals called biogenic amines, the theory suggests that depressions are
in specific brain areas (s not all) effective amines in the brain by blocking
their breakdown or exit from the body. Despite the theory's attractiveness, however,
the exact nature of the presumed chemical lesion in the brain has yet to be defined
Psychological theories of the cause of major depression remain equally unproved,
however, and clear familial associations of depressive illness along with the
responsiveness of the state to drugs do indicate that depression has some biological
substrate. Most modern theorists would agree that both biological and psychological
and often by some combination of these treatments. Most depressions are self-limited,
but selected treatment with modern therapies can shorten the duration of the disease
by many months. Treatment and hospitalization may also prevent suicide attempts.
Research indicates that certain well-defined methods of psychotherapy can help in the
treatment of some cases of depression, but no evidence exists that insight-oriented
psychoanalytic therapy alone is effective in serious cases, such as those accompanied
by suicidal thoughts or attempts. Psychiatric hospitalization is often necessary in such
cases, which are usually treated by drug or electroconvulsive therapy.
Three major classes of antidepressant drugs are available and effective: the tricyclic
drugs; a group characterized as "serotonin reuptake inhibitors"; and the monoamine
oxidase (MAO) inhibitors. All can be effective in about 75% of depressed patients;
selection of a particular drug is typically based on avoidance of particular side effects.
Tricyclics have been used since the early 1960s. As with the other antidepressants,
their exact mechanism of action is unknown but is believed to involve their effect on
the disposition of norepinephrine or serotonin in the brain. They are not stimulants in
fact they often cause sleepiness and effects may not be apparent until two to three
weeks after the start of treatment. Sleep disorders may then diminish, and a lightening
of mood becomes apparent, but continued treatment is needed for six to nine months
988, quickly became one of the most widely used
of all antidepressants. It blocks the reuptake of serotonin into brain cells and thus
increases the amount of serotonin available in the brain, as do the similar
antidepressants sertraline (Zoloft) and paroxetine (Paxil). This is thought to be the
mechanism of their action. They are unrelated to the tricyclics and MAO inhibitors.
The other major group of drugs, the monoamine oxidase inhibitors such as phenelzine,
prevent the formation of monoamine oxidase, an enzyme that breaks down biogenic
amines in the brain and intestinal tract. Their effectiveness is attributed to normalizing
the amount of amine in the brain. Because the enzyme ordinarily breaks down food
amines that would otherwise cause an increase in blood pressure, however, the body
is no longer protected from this effect when the drugs are used. Patients given the
drugs must control their diets accordingly. Because MAO inhibitors can also interact
with other drugs (including the other antidepressants) and cause serious side effects,
physicians prescribing them should provide instructions about necessary precautions.
In depressions severe enough to need psychiatric treatment, electroconvulsive therapy
(ECT) has been found effective but has been so misused and overused that a public
aversion to it exists. It is now most often used in cases of severe endogenous and
delusionary depressions. Important short-term side effects include confusion and
memory loss. ECT is at least as effective as any of the drugs.
Gilbert, Paul, Depression: The Evolution of Powerlessness
(1992) and Overcoming Depression
, 2d ed. (2000).
Gold, Mark S., The Good News about Depression: Cures and Treatments in the New Age of Psychiatry
, rev. ed. (1995).
Jackson, Stanley W., Melancholia and Depression
(1986; repr. 1990).
Karp, David A., Speaking of Sadness: Depression, Disconnection, and the Meanings of Illness
Kaufman, Miriam, Overcoming Teen Depression: A Guide for Parents
Klein, Donald F., and Wender, Paul H., Understanding Depression
, rev. ed. (2004).
Manning, Donna, and Frances, A. J., eds., Combined Pharmacotherapy and Psychotherapy for Depression
Merrell, Kenneth, Helping Students Overcome Depression and Anxiety
Solomon, Andrew, The Noonday Demon: An Atlas of Depression
Stark, Kevin D., Childhood Depression
Styron, William, Darkness Visible: A Memoir of Madness
Wolpert, Lewis, Malignant Sadness
(Cited from Grolier Multimedia Encyclopedia by Byck, Robert).
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