Several limitations should be considered. First, there was inconsistent reporting of variables needed to calculate treatment efficacy, treatment response, and symptom/diagnostic remission across RCTs. Although study investigators were contacted to obtain these data, this resulted in a limited number of RCTs included in treatment response and symptom/diagnostic remission analyses and may have influenced findings. Second, most of these RCTs focused on acute outcomes and were not designed with the goal of symptom/diagnostic remission. Thus, it may be that longer treatment durations and/or higher doses may yield improved symptoms/diagnostic remission rates for CBT and SRIs. Third, some moderator analyses had appropriate power to detect effects, but others had less power. Borenstein and colleagues [68] recommend 10 studies for moderator analyses. Thus, non-significant moderator findings should not be interpreted as a conclusive lack of association. Moreover, an examination of patient-level data may yield different moderator results, however such data are unavailable at this time.[46] Finally, there were limited characteristics available for extraction across RCTs. Although theoretically driven moderators were selected, there may be unexamined factors (e.g., homework compliance, medication adherence) omitted from these reports that influence treatment effects.
