Selecting Methodologies for the Evaluation of Differences in Time to Response Between Antidepressants.

Background: The delay in the therapeutic effect of antidepressants is a considerable impediment to their successful clinical use, and attention has recently been focused on antidepressant drugs that may have a faster onset of action.

Data Synthesis: Several methodologies exist for evaluating differences in time to response between antidepressants including the identification of the timepoint at which statistically or clinically significant differences between treatment groups emerge, pattern analysis, and survival analytical approaches. All have conceptual as well as practical advantages and disadvantages.

Conclusion: The survival analytical approach is generally considered to be the most rigorous and sensitive in detecting differences in the speed of response of antidepressants, but the other methodologies provide useful information.