If you fail an important examination, lose a job or lose a love, it is normal to feel depressed. If a close friend dies, it is also normal to feel depressed. But if you remain depressed for weeks or months, long after the depressing event has passed, then you may have the clinically significant depressive disorder called unipolar depression, the commonest of all major mental disturbances.
Novelist William Styron(1) writes movingly about his own experience with severe depression. The pain he endured convinced him that clinical depression is much more than a bad mood: He characterized it as “a daily presence, blowing over me in cold gusts” and “a veritable howling tempest in the brain” that can begin with a “gray drizzle of horror.” Unipolar depression does not give way to manic periods.
Psychologist Martin Seligman (2)(3) has called depression the “common cold” of psychological problems because nearly everyone has suffered it at some time. In the United States, depression accounts for the majority of all mental hospital admissions, but it is still believed to be underdiagnosed and undertreated.(4) The Wall Street Journal estimates that depression costs Americans about $43 billion each year, including the costs of hospitalization, therapy and lost productivity.(5)
But the human cost cannot be measured in dollars. Countless people in the throes of depression may feel worthless, lack appetite, withdraw from friends and family, have difficulty sleeping, lose their jobs and become agitated or lethargic. In severe cases, they may also have psychotic distortions of reality. Most worrisome of all, depressed persons run a high risk of suicide.
Cultural and regional variations
Cross-cultural studies indicate that the incidence of major depression varies widely throughout the world. While some of the variation may be the result of differences in reporting and in readiness or reluctance to seek help for depression, other factors seem to be at work, too. In Taiwan and Korea, for example, these include low rates of separation and divorce—factors known to be associated with high risk of depression in virtually all cultures. On the other hand, the stresses of war have undoubtedly inflated the rate of depression in the Lebanon.(6)
Some cases of unipolar depression, however, almost certainly have a genetic predisposition. Severe bouts with depression often run in families. (7)(8)(9) Further indication of a biological basis for depression comes from the favorable response that many depressed patients have to drugs that affect the brain’s neurotransmitters: norepinephrine, serotonin and dopamine.(10)(11)(12) Evidence also indicates that depression is related to lower brain wave activity in the left frontal lobe.(13)(14) In a few cases, depression may be caused by viral infection.(15) Such evidence leads some observers to believe that depression is really a collection of disorders having a variety of causes.(16)
A special form of unipolar depression seems to be related to sunlight deprivation. It appears most frequently among people who live in high latitudes. There, during the long, dark winter months, the incidence of depression runs high.(17) The aptly named seasonal affective disorder, or SAD, is related to levels of the light-sensitive hormone melatonin, which regulates our internal biological clocks.(18) Based on this knowledge, researchers have developed an effective therapy that regulates melatonin by exposing SAD sufferers daily to bright artificial light.(19)
Cycles of depression
Biology alone cannot entirely explain depression, however. We must also understand it as a mental and a behavioral condition. Initially, a negative event, such as losing a job, can make anyone feel depressed, but low self-esteem and a pessimistic attitude can fuel a cycle that keeps some individuals caught up in depressive thought patterns.(20)(21)(22)(23)
Probably because of low self-esteem, depression-prone people are more likely to perpetuate the depression cycle by attributing negative events to their own personal flaws or to external conditions that they feel helpless to change.(24)(25) (26)(27) Martin Seligman calls this learned helplessness. The resulting negative self-evaluation generates a depressed mode, which leads in turn
to negative behaviors such as crying. These behaviors encourage others to avoid the depressed individual. Consequently, depressed people feel rejected and lonely, which also feeds the cycle of their despair.(28)
A study of college students supports the notion that depressed people have a negative attribution style. Those who were depressed and who failed a test attributed their failure to a personal flaw—their lack of ability—while those depressed students who passed the test attributed their successes to luck. In comparison, non-depressed students took more credit for successes and blamed failures on external factors and on bad luck.(29) Moreover, students who have a negative attribution style have been found to earn lower grade point averages than their less negative-thinking classmates.(30)
The cognitive approach to depression points out that negative thinking styles are learned and modifiable. This implies that, if you work on changing the way you think, perhaps blaming yourself less and focusing more on constructive plans for doing better, you can ultimately change your feelings and your performance. Indeed, Peter Lewinsohn and his colleagues(31)(32) have found that they can treat many cases of depression effectively with cognitive-behavioral techniques. Their approach intervenes at several points in the cycle of depression to teach people how to change their
helpless thinking, to cope adaptively with unpleasant situations and to build more rewards into their lives.
Women are more vulnerable
Clinicians have noted that depression rates are higher for women than for men.(33)(34)(35)(36) According to Susan Nolen-Hoeksema,(37)(38) the response styles of men and women once they begin to experience negative moods may account for the difference. In this view, when women experience sadness, they tend to think about the possible causes and implications of their feelings. In contrast, men attempt to distract themselves from depressed feelings, either by shifting their attention to something else or by engaging in a physical activity that will take their minds off their
current mood state.
This model suggests that the more ruminative response of women—characterized by a tendency to concentrate on problems—increases women’s vulnerability to depression.(39) From a cognitive approach, paying attention to one’s negative moods can increase thoughts of negative events, which eventually increases the quantity and/or intensity of negative feelings.
Changes in patterns of depression
The incidence of depression and the age at which it strikes is changing—at least in the United States. According to Martin Seligman, depression is between 10 and 20 times as common as it was 50 years ago.(40) At mid-century, most casualties of depression were middle-aged women, but now it has become a teenage problem—still more prevalent in females than in males.
Currently, the average age of individuals diagnosed with depression in the United States is between 14 and 15 years. Seligman blames this increase in occurrence and decrease in age to three factors: (1) an out-of-control individualism and self-centeredness that focuses on individual success and failure, rather than group accomplishments, (2) the self-esteem movement, which has taught a generation of schoolchildren that they should feel good about themselves, irrespective of their efforts and achievements, and (3) a culture of victimology, which reflexively points the finger of blame at someone or something else.