Early intervention to preempt major depression among older black and white adults

Abstract

Objective: The study objective was to assess the efficacy of problem-solving therapy for primary care (PST-PC) for preventing episodes of major depression and mitigating depressive symptoms of older black and white adults. The comparison group received dietary coaching.

Methods: A total of 247 participants (90 blacks, 154 whites, and three Asians) with subsyndromal depressive symptoms were recruited into a randomized depression prevention trial that compared effects of individually delivered PST-PC and dietary coaching on time to major depressive episode and level of depressive symptoms (Beck Depression Inventory) over two years. Cumulative intervention time averaged 5.5-6.0 hours in each study arm.

Results: The two groups did not differ significantly in time to major depressive episodes, and incidence of such episodes was low (blacks, N=8, 9%; whites, N=13, 8%), compared with published rates of 20%-25% over one year among persons with subsyndromal symptoms and receiving care as usual. Participants also showed a mean decrease of 4 points in depressive symptoms, sustained over two years. Despite greater burden of depression risk factors among blacks, no significant differences from whites were found in the primary outcome.

Conclusions: Both PST-PC and dietary coaching are potentially effective in protecting older black and white adults with subsyndromal depressive symptoms from developing episodes of major depression over two years. Absent a control for concurrent usual care, this conclusion is preliminary. If confirmed, both interventions hold promise as scalable, safe, nonstigmatizing interventions for delaying or preventing episodes of major depression in the nation's increasingly diverse older population.

Trial registration: ClinicalTrials.gov NCT00326677.

Figures

Figure 1. Trajectories of Beck Depression Inventory Scores in PST-PC and DIET

Participants in both PST-PC and DIET demonstrated similar improvement in depressive symptoms (BDI). Improvements were sustained over two years. There was a significant quadratic and linear time effects (F(1,1356)=75.91, p<.001 and f p respectively but no significant intervention or by time effects>.114 and F(1,1356)=.46, p>0.496). When examining race as moderator, we observed baseline difference in blacks between interventions; thus, we ran the model co-varying for baseline score. We detected significant time effect (F(1,1115)=26.78, p<.001 for post-intervention through years but no significant race or effects.>