Moderation of antidepressant and placebo outcomes by baseline severity in late-life depression: A systematic review and meta-analysis.

Background: Baseline severity is a crucial moderator of trial outcomes in adult depression, with the advantage of antidepressants over placebo increasing as severity increases. However, this relationship has not been examined in late-life depression. Methods: PubMed, Embase, Web of Science, PsycINFO, and Cochrane were searched for studies published through September 2014. Randomized, acute phase, and double-blind studies comparing an antidepressant group with a placebo group in depressed elderly patients were included. Results: Nineteen studies met all inclusion criteria. Within-group effect sizes revealed significant improvement in antidepressant groups (g¼1.35, po.000), as well as in placebo groups (g¼.96, po.000). Change in depressive symptoms assessed by Hamilton Depression Rating Scale (HDRS) was moderated by baseline severity in antidepressant groups (Z¼2.67, p ¼.008) and placebo groups (Z¼4.46, po.000). However, this would be expected as a result of regression toward the mean, and mean differences between groups did not increase (r¼.19, p¼.469) as a function of baseline severity. Limitations: Limited to published data and information was only analyzed at the level of treatment groups. Conclusion: Baseline severity was not associated with an antidepressant–placebo difference and placebo responses are large in the treatment of depressed elderly people. We propose a stepwise approach, i.e., to initially offer elderly depressed patients psychosocial interventions and only consider antidepressants if patients do not respond.