Timing of clinical improvement and symptom resolution in the treatment of major depressive disorder

Background: Our objective was to assess for the relationship between timing of clinical improvement and resolution of depressive symptoms during the treatment of major depressive disorder (MDD). Thirty-nine MDD outpatients who responded following a 12-week, double-blind study comparing Hypericum perforatum, fluoxetine or placebo were included in the analysis. Methods: Onset of clinical improvement was defined as a 25% decrease in 17-item Hamilton Depression Scale (HDRS-17) scores that was not followed by a subsequent worsening of symptoms. Controlling for baseline symptom severity, we then assessed for the relationship between timing of clinical improvement and depressive symptom severity at endpoint. Results: Among responders, earlier clinical improvement predicted lower HDRS-17 scores at week 12 (p = 0013). This was also true of responders who received active treatment (n = 29, p = 0.0113) but not placebo responders (n = 10; p > 0.05). Finally, patients with an early onset of clinical improvement ( occurring during the first 2 weeks) had lower week 12 HDRS- 17 scores than patients with a late onset of clinical improvement (p = 0.0404). Conclusion: In the present work, earlier as well as early clinical improvement during treatment is predictive of greater symptom resolution at endpoint among responders. This was replicated among patients who received active treatment (either hypericum or fluoxetine) but not placebo. Copyright (c) 2008 S. Karger AG, Basel.