Manual-based psychotherapy and the involvement of family or friends may be the most effective components for reducing depressive symptoms in primary care, according to a recent study.

Investigators conducted an individual participant data (IPD) meta-analysis to identify the most effective components of collaborative care for depression in primary care. The analysis included 35 randomized clinical trials with 38 comparisons and a pooled sample of 20,046 adult patients (mean [SD] age = 50.8 [16.5] years, 68.4% female). The investigators, led by Hannah Schillok, MSc, of the Institute of General Practice and Family Medicine at LMU University Hospital at LMU Munich in Germany, aimed to determine which intervention components most significantly reduced depressive symptoms measured at 4 to 6 months postrandomization.

Using data from MEDLINE, Embase, Cochrane Library, PubMed, and PsycInfo, the investigators systematically extracted IPD and standardized depression scores based on validated self-report instruments. Linear mixed models with random intercepts for study and nested treatment effects were applied to examine the relationship between collaborative care components and depression outcomes. As a result of collinearity among intervention elements, the investigators employed principal component analysis, which yielded four core components: patient-centered care, therapeutic treatment strategy, measurement-based care, and integrated mental health care.

The therapeutic treatment strategy—defined by structured manual-based psychotherapy and involvement of family or friends—was associated with the largest reduction in depression severity, with a standardized mean difference of −0.07. The other components demonstrated smaller but statistically significant associations with depression outcomes (each −0.04). Overall, patients receiving collaborative care experienced greater symptom improvement compared with those in usual care groups, with a standardized mean difference of −0.20 across all studies.

The investigators evaluated collaborative care components and identified the therapeutic treatment strategy—particularly manual-based psychotherapy and family involvement—as the most strongly associated with reduced depression severity in this meta-analysis. They suggested prioritizing this component in future implementations of collaborative care. These findings may inform decisions in primary care settings and guide future intervention design based on evidence from individual participant data.

Full disclosures can be found in the published study.

Source: JAMA Psychiatry