Supplementary Material for: Cognitive behavioral therapy for late life depression (CBTlate): results of a multicenter, randomized, observer-blinded, controlled trial

Introduction: Different psychotherapeutic interventions for late-life depression (LLD) have been proposed, but their evaluation in large, multicenter trials is rare. Objective: The present study evaluated the efficacy of a specific cognitive behavioral therapy for LLD (LLD-CBT) in comparison with an unspecific supportive psychological intervention (SUI), both administered in a specialist psychiatric outpatient setting. Methods: In this randomized, controlled, parallel group trial we recruited participants (≥ 60 years) with moderate to severe depression at 7 trial sites in Germany. Participants were randomly assigned to LLD-CBT or SUI. The primary outcome was depression severity at the end of treatment measured by change on the Geriatric Depression Scale (GDS). Secondary outcomes included change in observer-rated depression, anxiety, sleep ratings, and quality of life throughout the treatment phase and at 6-month follow-up. Results: Between October 1, 2018, and November 11, 2020, we randomly assigned 251 patients to either LLD-CBT (n=126) or SUI (n=125), of whom 229 provided primary outcome data. There was no significant between-group difference in the change in GDS scores at the end of treatment (estimated marginal mean difference −1.01 [95% CI -2.88 to 0.86]; p=0.287). Secondary analyses showed significant improvements in several outcomes after 8 weeks and at follow-up in both treatment arms. Conclusions: Our data suggest that LLD-specific CBT and unspecific supportive treatment both provide clinical benefit in patients with moderate to severe LLD without evidence for superiority of LLD-CBT.