Exploring moderators of mirror exposure on pre- to post changes in body image outcomes: Systematic review and meta-analysis.

Random effects models demonstrated a medium effect of ME versus control conditions, on attitudinal BIC, from pre- to immediate posttreatment, small effect at follow-up (1 to 4 weeks posttreatment), and large effect on behavioral BIC pre- to immediate posttreatment. However, small sample sizes yielded nonsignificant findings and significant heterogeneity. Exploratory moderator analyses-ME type, ME dosage (session frequency, duration), and diagnosis-demonstrated that, among single group pre-post designs, higher ME dosage may be instrumental to pre-posttreatment improvements. Consistent with this finding, individual studies with high dosages of ME demonstrated the largest effect sizes. Conclusion: Results may suggest a strong ME effect on BIC at high dosages (>120 minutes). The current review highlights gaps in ME literature and the need for future clinical trials assessing ME, using a priori, high-quality research designs that further the understanding of ME's mechanisms of change.