Reduced illegal drug use found as benefit of depression treatment

 A study of youths with depression has found that reducing risk of later drug abuse constitutes a secondary benefit of successful depression treatment.

Published in the April/May issue of the Journal of Consulting and Clinical Psychology, the study headed by Duke University researchers found that only 10% of adolescents who saw their depression recede after 12 weeks of treatment were found to abuse drugs in a five-year follow-up. By comparison, 25% of youths who did not receive successful treatment for depression were found to abuse drugs in follow-up.

The young people ranged in age from 17 to 23 at the end of the study, and marijuana was the most widely used drug in the study sample. The association between depression treatment and substance use outcomes did not extend to subjects’ use of alcohol.

“It turned out that whatever they responded to—cognitive-behavioral therapy, Prozac, both treatments, or a placebo—if they did respond within 12 weeks they were less likely to develop a drug use disorder,” said John Curry, lead author of the study and a professor of psychology and neuroscience at Duke.

The study sample was derived from the well-known Treatment for Adolescents with Depression Study (TADS). The researchers speculate that improved mood regulation from various forms of depression treatment might account for the preventive effect on drug use, but they add they have no clear explanation as to why the same effect wasn’t seen for alcohol use.

In fact, in examining study subjects who suffered a second bout of depression during the study follow-up period, alcohol abuse sometimes was apparent prior to the second depressive episode, researchers found.