Characteristics of psychosocial interventions that improve depression in people with coronary heart disease: A systematic review with meta-regression

Background and aims: Depression is common in people with coronary heart disease (CHD) and predicts worse medical outcomes. Psychosocial interventions may improve depression, though the variations in methodology of existing trials mean that it is unclear which psychosocial interventions are effective in people with CHD. The review aims to identify the characteristics of psychosocial interventions that improve depression in people with CHD. Methods: Randomised controlled trials of psychosocial interventions in patients with CHD that included depression as an outcome were identified by searching major electronic databases. For eligible studies, the main characteristics of the intervention were coded into 12 categories: general discussion, education, skills training, exercise, behavioural therapy, relapse prevention, problem solving, cognitive behavioural therapy, social support, relaxation, biofeedback, others. Standardised mean difference (SMD) in depression score were calculated for each intervention and random effects meta-regression was used to examine the relationships between individual intervention characteristics and depression outcomes. Results: 56 independent studies were identified, providing data on 58 separate interventions. Interventions including education (SMD=0.14, p<0.0005), exercise (SMD=0.17, p=0.04), problem solving (0.36, p=0.001), cognitive behavioural therapy (SMD=0.25, p<0.0005), social support (SMD=0.16, p=0.03) and relaxation (SMD=0.17, p=0.006) were associated with improvement in depression status. Interventions were usually highly mixed, however, including between 1 and 7 individual components. On meta-regression no single intervention characteristic was associated with improved depression status. Conclusions: Psychosocial interventions used in CHD are highly complex in their structure. Whilst some trials of psychosocial interventions have clearly shown improvement in depression, it remains unclear what combination of characteristics are required to improve depression in CHD.