An Automated Treatment Decision Rule for Precision Assignment to Psychosocial Interventions for Late-life Depression

Importance: Most older adults with depression do not have access to efficacious psychotherapies, due to critical clinician shortage. Even when treated, response rates are limited to about 50%. A Treatment Decision Rule (TDR) can maximize treatment efficacy and resources by assigning patients to their optimal intervention. This is the first study to develop TDR for late-life depression designed for community settings. Objectives: To develop a scalable TDR for assignment to simple psychotherapies or care-as-usual interventions for late-life depression that can be delivered easily in community settings. Participants: The sample included 427 older adults with major depression.Design: In this prognostic study, older adults aged 60 or older with major depression participated in one of four randomized controlled trials comparing psychotherapy to care-as-usual. Setting: Participants were recruited outpatient and community settings of Weill Cornell Medicine and the University of California San Francisco (UCSF) between 2002-2011. Data were analyzed from May 2023 to January 2025.Interventions: Participants received 8 to 14 sessions of (1) simple psychotherapies (problem-solving therapy, psychotherapy for late-life depression and medical burden) or (2) care-as-usual conditions (supportive therapy, treatment as usual, or case management).Main Outcomes and Measures: Our primary outcome was mean reduction in depression severity (Hamilton Depression Rating Scale; HAM-D). We applied a data-driven Generated Effect Modifier TDR to identify the optimal intervention for each patient based on baseline characteristics (demographics, depression severity, social support, cognitive impairment, and disability). The selected TDR model maximized depression reduction and proportion of patients treated with care-as-usual interventions.Results: The TDR-based assignment improved expected reduction in depression severity by 34% compared to care-as-usual assignment and was superior to assignment of all patients to psychotherapy. Older adults with higher depression severity, stronger social support, and lower cognitive functioning should be assigned to psychotherapy. Older adults with lower depression severity, higher cognitive functioning, and low social support would benefit from care-as-usual interventions.Conclusions and Relevance: This automatic TDR can be applied in community settings to inform assignment based on baseline characteristics to increase precision, cost-effectiveness and response rates among older adults with depression.Trial Registration: NCT00601055, NCT00151372, NCT00052091, NCT00540865