Objective: More than half of the older adults respond only partially to first-line antidepressant pharmacotherapy. Our objective was to test the hypothesis that a depression-specific psychotherapy, Interpersonal Psychotherapy (IPT), when used adjunctively with escitalopram, would lead to a higher rate of remission and faster resolution of symptoms in partial responders than escitalopram with depression care management (DCM).
Method: We conducted a 16-week randomized clinical trial of IPT and DCM in partial responders to escitalopram, enrolling 124 outpatients aged 60 and older. The primary outcome, remission, was defined as three consecutive weekly scores of 7 or less on the Hamilton rating scale for depression (17-item). We conducted Cox regression analyses of time to remission and logistic modeling for rates of remission. We tested group differences in Hamilton depression ratings over time via mixed-effects modeling.
Results: Remission rates for escitalopram with IPT and with DCM were similar in intention-to-treat (IPT vs. DCM: 58 [95% CI: 46, 71] vs. 45% [33,58]; p = 0.14) and completer analyses (IPT vs. DCM: 58% [95% CI: 44,72] vs. 43% [30,57]; p = 0.20). Rapidity of symptom improvement did not differ in the two treatments.
Conclusion: No added advantage of IPT over DCM was shown. DCM is a clinically useful strategy to achieve full remission in about 50% of partial responders.
Trial registration: ClinicalTrials.gov NCT00177294.