One hundred and twenty-seven studies, with at least 5,930 participants, were included in the review.
Psychoeducational interventions had significant effects on burden (42 studies; ES -0.15, 95% CI: -0.25, -0.04, p<0.01), depression (32 studies; ES -0.27, 95% CI: -0.41, -0.13, p<0.001), SWB (13 studies; ES 0.24, 95% CI: 0.04, 0.44, p<0.05), ability or knowledge (34 studies; ES 0.46, 95% CI: 0.28, 0.64, p<0.001; significant heterogeneity, p<0.001) and symptoms of the care receiver (33 studies; ES -0.17, 95% CI: -0.29, -0.04, p<0.01), but not institutionalisation. Subgroup analysis demonstrated that 'active' psychoeducational interventions were more effective than 'information only' interventions.
CBT was significantly associated with improvements in burden (9 studies; ES -0.36, 95% CI: -0.73, -0.01, p<0.01) and depression (11 studies; ES -0.70, 95% CI: -1.10, -0.30, p<0.01), but not with any other outcomes.
Counselling had a significant effect on burden (4 studies; ES -0.50, 95% CI: -0.86, -0.14, p<0.001), and supportive interventions improved SWB (1 study; ES 2.03, 95% CI: 1.36, 2.70, p<0.001).
Training of care receiver was significantly associated with symptoms of the care receiver (8 studies; ES -0.35, 95% CI; -0.67, -0.02, p<0.05).
Respite was significantly associated with burden (12 studies; ES -0.26, 95% CI; -0.39, -0.12, p<0.001), depression (10 studies; ES -0.12, 95% CI; -0.24, -0.00, p<0.01) and SWB (5 studies; ES 0.27, 95% CI; 0.03, 0.51, p<0.05).
Multicomponent interventions were only significantly associated with delayed institutionalisation (15 studies; OR 0.65, 95% CI; 0.44, 0.98, p<0.05; significant heterogeneity. p<0.001). Subgroup analysis demonstrated that 'structured' multicomponent approaches were more effective than 'unstructured' approaches.
Regression analysis demonstrated variation in effects by study participant, gender, year of publication and study design.