A study of more than 800 East Baltimore residents has led researchers from the Johns Hopkins School of Medicine to challenge long-held assumptions about depression, including the belief that women are more vulnerable to severe depression than men.
In fact, "men and women are equally affected by major depression," said Dr. Alan J. Romanoski, an assistant professor of psychiatry and lead author of the study, which was released today .
He defined major depression as characterized by extreme sadness, difficulty concentrating, disturbances of sleep, appetite, sexual drive and energy, and even by hallucinations.
The study found that men and women are equally vulnerable to depression influenced by a lack of employment outside the home. People also appear to be equally vulnerable to major depression regardless of their race, income and education levels, according to the study.
On the other hand, the study found, "non-major depression" -- defined as intermittent depression, or briefly severe depressions triggered by life events such as a death, divorce or unemployment -- occurs more often in women than in men, by 10 times.
The Hopkins scientists said their findings challenge a traditional system of dividing depression into two categories: biologic depression caused by chemical imbalances or genetics, and "reactive" depression caused by traumatic life events.
They found that people depressed as a result of chemical imbalances are just as vulnerable to stressful events in their lives, if not more so, than people with reactive depression.
Patients treated with anti-depressant drugs who are diagnosed with major depression need a lot more than drugs and routine check-ups, Dr. Romanoski said.
"Because major depression can be influenced by deaths, divorces and other difficult life events, people who have it also need psychotherapy and behavioral change," he said.
The paper will appear in this month's issue of the British journal Psychological Medicine.
Subjects in the study were drawn from 3,481 East Baltimore adults chosen at random and interviewed for two hours each.
Those who showed any signs of psychological symptoms during the interviews were invited to undergo an additional RTC standardized psychiatric examination, and 810 people agreed to participate.
The exams included questions about each subject's psychiatric history and symptoms, family history and personal background.
Using that data, the researchers concluded that 5.9 percent of the 810 subjects were clinically depressed. The national average is 2 percent to 10 percent of the population.
Of that 5.9 percent, about 1 percent was found to have major depression, 3.4 percent displayed non-major depression, while the remaining 1.4 percent were depressed in connection with some other disorder, such as alcoholism or dementia.