Objective: To examine the time to response for both pharmacotherapy and psychotherapy in the Treatment for Adolescents with Depression Study (TADS). Method: Adolescents (N = 439, ages 12 to 17 years) with major depressive disorder were randomized to fluoxetine (FLX), cognitive-behavioral therapy (CBT), their combination (COMB), or pill placebo (PBO). Defining response as very much improved or much improved on the Clinical Global Impression-Improvement Scale (CGI-I), survival analyses using Cox proportional hazards models, and Kaplan-Meier curves were conducted to evaluate time to first response and time to stable response for subjects receiving pharmacotherapy (COMB, FLX, PBO) as well as for subjects receiving CBT (COMB, CBT). Direct comparisons between pharmacotherapy and CBT were not made because of differences in visit schedules. Results: Based on pharmacotherapist CGI-I scores, COMB and FLX showed faster onset of benefit than PBO on time to response and time to stable response (p less than 0.001), and COMB was faster than FLX on time to stable response (p = 0.034). The probability of sustained early response was approximately threefold greater for COMB than PBO, twofold greater for FLX than PBO, and 1.5-fold greater for COMB than FLX. On the psychotherapist CGI-I scores, both first response and stable response occurred faster in COMB than CBT (p less than 0.001), with a probability of sustained early response approximately threefold greater for COMB than CBT. Conclusions: In the acute treatment of depressed adolescents, FLX and COMB accelerate response relative to PBO, and COMB accelerates response relative to CBT alone. (Contains 2 figures and 2 tables.)