Most depressed teens who receive treatment appear to recover, but the condition recurs in almost half of adolescent patients and even more often among females, according to a report posted online now that will appear in the March 2011 print issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

Major depressive disorder affects approximately 5.9 percent of teen females and 4.6 percent of teen males, according to background information in the article. "It is associated with functional impairment, risk of suicide and risk of adult depression," the authors write. "Thus, it is important to investigate not only the efficacy of adolescent major depressive disorder treatments but also whether they reduce the risk of subsequent negative outcomes, especially depression recurrence."

John Curry, Ph.D., of Duke University Medical Center, Durham, N.C., and colleagues studied 196 adolescents (86 males and 110 females) who participated in the Treatment for Adolescents With Depression Study (TADS). The teens were randomly assigned to one of four short-term treatment interventions (medication with fluoxetine hydrochloride, cognitive behavioral therapy, a combination of the two or placebo) and followed up for five years.

Almost all participants (96.4 percent) recovered from their initial episode of depression during the follow-up period, including 88.3 percent who recovered within two years. Those who responded to a 12-week treatment session (short-term responders) were more likely to have recovered by two years (96.2 percent vs. 79.1 percent). However, two-year recovery was not associated with any particular type of treatment.

Of the 189 teens who recovered from depression, 88 (46.6 percent) experienced a recurrence. "Contrary to our hypotheses, neither full response to short-term treatment nor treatment with a combination of fluoxetine and cognitive behavioral therapy reduced the risk of recurrence," the authors write. "However, short-term treatment non-responders were more likely to experience recurrence than full and partial responders. Females were significantly more likely to have a recurrence than males."

Teens who also had an anxiety disorder were more likely to experience recurrence (61.9 percent vs. 42.2 percent of those without anxiety disorders). In addition, participants whose depression returned had higher scores on scales of suicidal thoughts and behaviors.

"Our results reinforce the importance of modifying a short-term treatment that leads to partial response or non-response because these were associated with less likelihood of recovery in two years," the authors write. "The finding that recurrence rates increased significantly from two to three years after baseline suggests that recurrence prevention efforts, such as symptom or medication monitoring or cognitive behavioral therapy booster sessions may be of value beyond the [18-week] maintenance period included in TADS."

"Female sex was the most robust predictor of recurrence, indicating the importance of understanding and reducing the vulnerabilities of female adolescents to recurrent episodes."

This study was funded by a grant from the National Institute of Mental Health.