Do treatment effects vary among differing baseline depression criteria in depression in Alzheimer's disease study ± 2 (DIADS-2)?

Objective: To determine if the effect of sertraline in the depression in Alzheimer's disease study - 2 (DIADS-2) differed in subgroups of patients defined by baseline depression criteria.

Methods: DIADS-2 was a randomized, parallel, placebo-controlled, multicenter trial designed to evaluate the efficacy and safety of sertraline (target dose of 100 mg/day) for the treatment of depression in patients with Alzheimer's disease. DIADS-2 enrolled 131 patients who met criteria for the depression of Alzheimer's disease (dAD). Analyses reported here examined if the effect of sertraline differed in various subgroups, including those meeting criteria for major depressive episode (MaD), minor depressive episode (MiD), and Alzheimer's-associated affective disorder (AAAD) at baseline.

Results: At baseline, 52 of 131 participants (39.7%) met criteria for MaD, 54 (41.2%) for MiD, and 90 (68.7%) for AAAD. For the primary outcome of modified Alzheimer's Disease Cooperative Study Clinical Global Impression of Change (mADCS-CGIC) scores at 12 weeks of follow-up, the odds of being at or better than a given mADCS-CGIC category did not significantly differ between the two treatment groups for those patients with MaD at baseline (OR(sertraline) = 0.66 [95% CI: 0.24, 1.82], p = 0.42); tests for interactions between treatment group and baseline depression diagnostic subgroup were not significant for MaD versus MiD versus neither (χ(2) = 1.05 (2df), p = 0.59) or AAAD versus no AAAD (χ(2) = 0.06 (1df), p = 0.81).

Conclusions: There was no evidence that sertraline treatment was more efficacious in those patients meeting baseline criteria for MaD compared to MiD or to neither.