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

Purpose Mirror exposure (ME) is embedded within cognitive behavioral treatment of body image concern (BIC), and existing literature demonstrates its potential value as a BIC intervention. The purpose of the study is to provide a meta-analytic review of ME effects on attitudinal and behavioral BIC. Methods Twelve studies met inclusion criteria, yielding six between-group and 18 within-group comparisons. Results 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.

Automated summary

Mirror exposure (ME) has a significant effect in cognitive behavioral treatment of body image concern, especially at high dosages. However, due to small sample sizes, results are not always significant and there is significant heterogeneity present.