Collaborative Care for Depression in Chronic Illness: A Narrative Review.

Abstract

Depression commonly coexists with chronic medical illness and is associated with impaired self-management, poor adherence, increased healthcare utilization, and higher mortality. To synthesize evidence published between 2000 and late 2025 on the effectiveness of the Collaborative Care Model (CoCM) for depression in adults with chronic medical illness, with particular attention to contemporary U.S. implementation, policy, and equity considerations. A narrative review of randomized controlled trials, pragmatic and implementation studies, systematic reviews, and policy analyses was conducted using PubMed, PsycINFO, and Scopus. Evidence addressing collaborative care for depression in adults with chronic medical illness was identified and synthesized thematically in accordance with best practices for narrative reviews. Landmark trials and meta-analyses demonstrate that collaborative care consistently improves depression outcomes across chronic disease populations. More recent studies indicate that CoCM remains effective in real-world settings using digital registries, telepsychiatry, and population health workflows, although implementation remains uneven due to workforce and access constraints. Collaborative care represents a durable, evidence-based approach for integrating depression management into chronic illness care. Sustaining effectiveness as systems scale will require preserving core model components while addressing persistent workforce, digital, and equity barriers.