The methodological limitations of this review must be acknowledged. The first limitation concerns the small number of studies included in our review and the heterogeneity among the studies. Drawing comparisons between studies was made difficult by the fact that they targeted various levels of stigma, employed different measures of stigma and evaluated different types of interventions. Additionally, the studies varied in methodological quality and none received a high score on the Study Quality Appraisal Checklist. Secondly, it is possible that relevant studies were not identified. To minimize this possibility, we conducted a comprehensive literature search using several broad search terms across seven electronic databases. As well, our search strategy included a grey literature review and several supplementary methods, which minimized the likelihood that the internal validity of our review was threatened by publication bias and file drawer effects. The final major limitation is that the literature search was restricted to English language publications. Perhaps as a consequence of this inclusion criterion, only English-speaking jurisdictions were represented in the included studies. Consequently, the cross-cultural generalizability of our findings may be restricted.
