Mediators and Moderators of Treatment Outcome for Anxiety and Depression: A Meta-Analysis

Lauryn Garner, Fordham University


Efficacious treatments have been established that are known to reduce symptoms of anxiety and depression. However, there is less consensus in the literature regarding the specific factors that change throughout treatment and subsequently cause symptom reduction. To explore these factors and determine their relative importance, we conducted a meta-analysis to explore mediators and moderators of treatment outcome for anxiety and depression. Using specific search terms, 17,550 articles were examined for inclusion in this study and a final pool of 40 cognitive behavioral treatment studies were used for data analysis. Similar mediators and moderators were clustered together, and mean effect sizes and homogeneity statistics were computed. There was no support for cognitive mediators of anxiety symptom reduction, but results revealed a medium effect size for cognitive mediators of depression. Effect sizes for interpersonal, duration of symptoms/onset, comorbidity, and anxiety sensitivity moderators of anxiety symptom reduction ranged from small to large. Similar results were found for depression, with effect sizes for personality, therapeutic, and depression severity/comorbidity moderators ranging from small to medium. Thus, these mediators and moderators should be a focus of future research and clinical practice. Due to the small pool of studies that were available for inclusion in this meta-analysis, future research should employ more rigorous methodology and explore mediators and moderators in other forms of treatment.

Subject Area

Clinical psychology|Health sciences|Counseling Psychology|Mental health|Experimental psychology

Recommended Citation

Garner, Lauryn, "Mediators and Moderators of Treatment Outcome for Anxiety and Depression: A Meta-Analysis" (2019). ETD Collection for Fordham University. AAI22589067.