Objective: The aim of this study was to examine the impact of co-morbid illnesses on treatment outcomes in depressed children and adolescents aged 7-17 who were treated with fluoxetine.
Method: This data set was drawn from two large clinical trials involving children and adolescents with depression. Subjects with a diagnosis of major depressive disorder and depressive symptoms of at least moderate severity as defined by a Children's Depression Rating Score, Revised (CDRS-R) total score >or=40 and a Clinical Global Impressions-Severity (CGI-S) rating >or=4 were included. Subjects were randomized to receive fluoxetine or placebo over an 8-week period. Predictor analyses examining two primary outcomes were conducted: (1) Response based on Clinical Global Impressions-Improvement (CGI-I) score of 1 or 2, and (2) remission based on CDRS-R score of <or=28. Logistic regression models were run to assess whether anxiety disorders were a predictor of response or remission.
Result: A total of 309 study participants were included. The only factor found to influence response was treatment with fluoxetine (p = 0.022, odds ratio [OR] = 2.08, 95% confidence interval [CI] 1.30, 3.31). Several factors were found to influence remission: Treatment with fluoxetine (p < 0.0001, OR = 3.17, 95% CI 1.80, 5.57), gender (p = 0.024, OR = 1.90, 95% CI 1.09, 3.30), and number of co-morbid diagnoses (p = 0.026, OR 0.73, 95% CI 0.55, 0.96).
Conclusion: Anxiety disorders alone did not predict response or remission, but the total number of co-morbid illnesses was associated with remission in depressed children and adolescents treated with fluoxetine.