DEPRESSION

in economics, major downswing in the business cycle (q.v.) that is characterized by sharply reduced industrial production, widespread unemployment, serious declines or cessations of growth in construction activity, and great reductions in international trade and capital movements. Unlike minor business contractions that may occur in one country independently of business cycles in other countries, severe depressions have usually been nearly worldwide in scope. The Great Depression (q.v.) beginning in 1929, for example, was the most severe and widespread economic decline in the 20th century. Compare recession; panic. in psychology, a mood or emotional state that is marked by sadness, inactivity, and a reduced ability to enjoy life. A person who is depressed usually experiences one or more of the following symptoms: feelings of sadness, hopelessness, or pessimism; lowered self-esteem and heightened self-depreciation; a decrease or loss of ability to enjoy daily life; reduced energy and vitality; slowness of thought or action; loss of appetite; and disturbed sleep or insomnia. Depression differs from simple grief, bereavement, or mourning, which are appropriate emotional responses to the loss of loved persons or objects. Where there are clear grounds for a person's unhappiness, depression is considered to be present if the depressed mood is disproportionately long or severe vis--vis the precipitating event. When a person experiences alternating states of depression and mania (extreme elation of mood), he is said to suffer from a manic-depressive psychosis (q.v.). Depression is probably the most common psychiatric complaint and has been described by physicians from at least the time of Hippocrates, who called it melancholia. The course of the disorder is extremely variable from person to person; it may be fleeting or permanent, mild or severe, acute or chronic. Depression is more common in women than in men. The rates of incidence of the disorder increase with age in men, while the peak for women is between the ages of 35 and 45. Depression can have many causes. The loss of one's parents or other childhood traumas and privations can increase a person's vulnerability to depression later in life. Stressful life events in general are potent precipitating causes of the illness, but it seems that both psychosocial and biochemical mechanisms can be important causes. The chief biochemical cause seems to be the defective regulation of the release of one or more naturally occurring monoamines in the brain, particularly norepinephrine and serotonin. Reduced quantities or reduced activity of these chemicals in the brain is thought to cause the depressed mood in some sufferers. There are three main treatments for depression. The two most important are psychotherapy and drug therapy. Psychotherapy aims to resolve any underlying psychic conflicts that may be causing the depressed state, while also giving emotional support to the patient. Antidepressant drugs, by contrast, directly affect the chemistry of the brain, and presumably achieve their therapeutic effects by correcting the chemical imbalance that is causing the depression. The tricyclic antidepressant drugs are thought to work by inhibiting the body's physiological inactivation of the monoamine neurotransmitters. This results in the buildup or accumulation of these neurotransmitters in the brain and allows them to remain in contact with nerve cell receptors there longer, thus helping to elevate the patient's mood. By contrast, the antidepressant drugs known as monoamine oxidase inhibitors interfere with the activity of monoamine oxidase, an enzyme that is known to be involved in the breakdown of norepinephrine and serotonin. In cases of severe depression in which therapeutic results are needed quickly, electroconvulsive therapy has proven helpful. In this procedure, a convulsion is produced by passing an electric current through the person's brain. In many cases of treatment, the best therapeutic results are obtained by using a combination of psychotherapy with drug therapy or with electroshock treatment.