Primary care and community interventions for multimorbidity involving depression or anxiety: systematic review with meta-analysis.

Objective: To identify and characterise primary care or community based interventions for patients with multimorbidity involving depression or anxiety, and to determine their effectiveness for improving patients' mental health, physical health, and quality of life. Design: Systematic review with meta-analysis. Data sources: Medline, Embase, Cochrane Library, CINAHL, PsycInfo, and Web of Science databases, from inception to 11 November 2024. Eligibility criteria for selecting studies: Included studies were randomised controlled trials of primary care or community based interventions targeting adults with depression or anxiety disorders and one or more long term physical conditions. Risk of bias assessment used the Cochrane risk of bias tool. Interventions were categorised as organisational or patient oriented, and were subgrouped by intervention type. Intervention components were systematically categorised, and effects on mental health and quality of life outcomes were meta-analysed in groups defined by intervention type and assessment time point. Physical health outcomes were too heterogenous to meta-analyse and were synthesised without meta-analysis with Fisher's method for combining P values. Results: 29 randomised controlled trials comprising 9487 participants were included. High quality evidence was found for organisational interventions (n=10, including collaborative care, stepped care, and post-discharge interventions) which resulted in small improvements in symptoms of depression (standardised mean difference -0.25, 95% confidence interval (CI) -0.43 to -0.06) and quality of life (0.21, 0.01 to 0.41), but had no effect on symptoms of anxiety at the end of the intervention. No effect on depression or anxiety symptoms was observed, and no data for quality of life were found from organisational interventions at the late follow-up period (18-24 months). In the subgroup analysis, collaborative care resulted in sustained improvements in symptoms of depression at 18-24 months. Synthesis without meta-analysis showed evidence of benefit from organisational interventions (specifically collaborative care) on physiological (eg, haemoglobin A Conclusions: The study showed that interventions improved mental health, physical health, and quality of life outcomes in people with multimorbidity involving depression or anxiety, but the effects were small and, for patient oriented interventions in particular, diminished over time. Systematic review registration: PROSPERO CRD420251004355.