The study, carried out by psychiatrists at Columbia University and the New York State Psychiatric Institute, is published in the September issue of the British Journal of Psychiatry.

In 1983, researchers interviewed 755 adolescents who were aged around 16-years-old. The interview was designed to find out if the teenagers had any mood, anxiety, disruptive, eating, or substance use disorders. The participants were re-interviewed in their early-20s and again in their early-30s.

Of the 755 teenagers interviewed, 62 (8.2%) had minor depression. Minor depression is a mood disorder lasting at least two weeks, with similar but milder symptoms than clinical depression. Symptoms may include feeling down, losing interest in activities ( anhedonia), sleeping problems, and poor concentration.

The researchers found that teenagers with minor depression were significantly more likely to have major depression when they reached their 20s and 30s than those who did not show signs of depression in their teens.

In addition, teenagers with minor depression were at greater risk of developing anxiety disorders and eating disorders when they grew up.

Writing in the British Journal of Psychiatry, the researchers said: “The findings support the hypothesis that adolescents with minor depressive disorder are at elevated risk for major depressive disorder during adulthood. They may also be at elevated risk for other psychiatric disorders during adulthood.”

The researchers have called for further research to investigate if minor depression in adolescence contributes to the development of more serious problems in later life, or if it is a ‘prodromal form’ (an early phase) of major depressive disorder.

Source: Royal College of Psychiatrists (Press Release)