Rapid response to antidepressants and correlation with response and remission after acute treatment

Abstract

Background: Pharmacological treatment of depression with antidepressants is well established, but the desired therapeutic effect may take several weeks to manifest. Few studies have compared response time and improvement rates and its prognostic value for different antidepressants. An accurate response predictor could help guide decisions on whether to maintain an antidepressant for longer or switch. Methods: A secondary analysis data from four clinical trials involving four different antidepressants (venlafaxine, sertraline, mirtazapine, and fluoxetine) and placebo was performed to evaluate the relationship between response time and acute treatment outcome. All patients from the four trials were diagnosed as having a Major Depression episode. Contingency tables were built from the combination of dichotomous variables for all groups. Positive predictive value (PPV), negative predictive value (NPV), sensitivity, specificity and accuracy were determined. Results: Response > 50 % after two weeks of treatment was associated with remission at the end of the acute phase (eight weeks) of treatment for all antidepressants tested, except fluoxetine. Response to mirtazapine within one week was a predictor of response and/or remission after acute treatment, having a high level of accuracy as a predictor of remission for early improvement > 50 %. Mirtazapine also promoted a more rapid response compared with the other antidepressants trialed. Limitations: Severity at baseline varied among the trials and only a small sample was included in the fluoxetine group. Conclusions: The present study revealed that early evaluation (at 1 and 2 weeks) might be beneficial as a treatment strategy, given the heterogeneous patterns of response between antidepressants.

Keywords

• Antidepressant
• Antidepressant rapid response
• Antidepressant response time
• Major depression