Adults who experienced even a single bout of major depressive disorder (MDD) in adolescence are likely to demonstrate pervasive psychosocial impairment, according to research by psychologist Peter Lewinsohn, PhD, of the Oregon Research Institute, published in the Journal of Abnormal Psychology (Vol. 112, No. 3) last month.

Lewinsohn and colleagues assessed 941 men and women for depression and other disorders twice during adolescence and again at age 24. The participants, who were first assessed in 1988, attended high school in Oregon. The study controlled for factors such as having more than one psychiatric disorder during adolescence, having a recurrence of depression in early adulthood, psychosocial functioning levels in adolescence and level of depression at the time of the adult assessment.

Young adults who had experienced an episode of MDD, regardless of other factors, exhibited pervasive impairments across psychosocial functioning, including occupational performance, interpersonal functioning, quality of life and physical well-being. Most poignantly, Lewinsohn says, when other factors were controlled, adolescent MDD translated into greatly reduced life satisfaction.

The research suggests that depression in adolescence indicates a broad, lasting tendency toward psychosocial problems that should be seen as a serious, stand-alone risk factor, Lewinsohn says.

"We know that there are certain things that predispose people to being depressed, like being pessimistic," Lewinsohn says. "And now we're seeing there are traits like this evident after a depressive episode that weren't there before the depression. It's a scar [that] can affect a person throughout their life."

They also found that people who've had an episode of MDD demonstrate higher than average incidence of mild depression symptoms, such as sleeping and appetite problems, when not fully depressed, Lewinsohn adds. "We think it's these residual symptoms that make these individuals more vulnerable to MDD," he says.

People who've been diagnosed as depressed in adolescence should be watched for new signs of depression and should be taught to identify signs that they may be becoming depressed again, Lewinsohn says. More importantly though, knowing there are lifelong implications after a bout of depression makes prevention crucial, he says.

Lewinsohn and his colleagues plan to continue collecting data on the participants, including an assessment at age 30 about parenting and the mental health of their children.

--K. KERSTING