Precision Assignment to Psychosocial Interventions for Late-Life Depression: An Automated Treatment Decision Rule.

Importance Most older adults with depression lack access to efficacious psychotherapies due to a critical clinician shortage. Even when treated, response rates are limited to approximately 50%. A treatment decision rule (TDR) may maximize treatment efficacy and resources by assigning patients to their optimal intervention. This is the first study to propose a TDR for late-life depression designed for community settings. Objective To develop a scalable TDR for assignment to a psychotherapy or usual care intervention for late-life depression that can be delivered easily in community settings. Design, Setting, and Participants In this prognostic study, adults 60 years or older with major depression participated in randomized controlled trials comparing psychotherapy with usual care. Participants were recruited from outpatient and community settings of Weill Cornell Medicine and the University of California San Francisco between 2002 and 2011. Data were analyzed from May 2023 to May 2025. Interventions Participants received either psychotherapy (problem-solving therapy, psychotherapy for late-life depression and medical burden) or usual care (supportive therapy, treatment as usual, or case management). Main Outcomes and Measures The primary outcome was mean reduction in depression severity (measured by the Hamilton Depression Rating Scale [HAM-D]). A generated effect modifier TDR was applied to identify the optimal intervention for each patient based on baseline characteristics (demographics, depression severity, social support, cognition, and disability). The TDR maximized depression severity reduction and the proportion of patients treated with the usual care intervention. Results In 427 older adults with late-life depression (mean [SD] age, 72.7 [8.7] years; 70% female), the predicted HAM-D score reduction with TDR-based intervention was a mean of 49.1% (95% CI, 47.4%-51.0%). The TDR improved expected depression severity reduction by 34% compared with usual care (HAM-D reduction, 36.6% [95% CI, 34.5%-38.7%]) and the TDR was somewhat superior to assigning all patients to receive psychotherapy (HAM-D reduction, 46.7% [95% CI, 44.2%-48.8%]). Older adults with higher depression severity, stronger social support, and lower cognitive functioning should receive psychotherapy; those with lower depression severity, higher cognitive functioning, and low social support would benefit from usual care. Conclusions and Relevance In this study of older adults with depression, pending prospective testing, the automatic TDR may be used in community settings to inform treatment assignment. The TDR has the potential to increase precision, cost-effectiveness, and response rates among older adults with depression. Trial Registration ClinicalTrials.gov Identifiers: NCT00601055, NCT00151372, NCT00052091, NCT00540865.