Intergroup contact and mental health stigma: A comparative effectiveness meta-analysis.

Mental health stigma is a substantial problem all over the world. Although many interventions to reduce stigma exist, there is considerable methodological variability, making it difficult for decision-makers to determine what strategies are the most effective and what characteristics make them so. To this end, we conducted a meta-analysis on intergroup contact strategies and examined several potential moderators. We searched 5 databases for published and unpublished studies and retrieved 101 studies from 24 countries that could be included in the analyses. Ninety studies assessed outcomes immediately after the intervention (n = 15,826), 33 in the short-term (n = 3,697), and 7 in the medium-term (n = 842). The effect of contact was significant and small-to-medium in size at all three timepoints, d = -0.384, -0.334, and -0.526, respectively. Intervention effectiveness did not differ between contact with or without an educational component, different contact mediums, or the mental illness of the outgroup member. However, the effect of contact was stronger in non-Western countries and in university students and health professionals compared to community members. These results may inform policy-makers of the most effective and suitable stigma-reduction initiatives to invest in and can guide researchers towards important avenues for future research.