Meta-analysis of emotion recognition deficits in major depressive disorder

Background. Many studies have explored associations between depression and facial emotion recognition (ER).However, these studies have used various paradigms and multiple stimulus sets, rendering comparisons difficult.Few studies have attempted to determine the magnitude of any effect and whether studies are properly powered to detectit. We conducted a meta-analysis to synthesize the findings across studies on ER in depressed individuals comparedto controls.Method. Studies of ER that included depressed and control samples and published before June 2013 were identified inPubMed and Web of Science. Studies using schematic faces, neuroimaging studies and drug treatment studies wereexcluded.Results. Meta-analysis of k = 22 independent samples indicated impaired recognition of emotion [k = 22, g =−0.16, 95%confidence interval (CI) −0.25 to −0.07, p < 0.001]. Critically, this was observed for anger, disgust, fear, happiness andsurprise (k’s = 7–22, g’s =−0.42 to −0.17, p’s < 0.08), but not sadness (k = 21, g = −0.09, 95% CI −0.23 to +0.06, p = 0.23).Study-level characteristics did not appear to be associated with the observed effect. Power analysis indicated that asample of approximately 615 cases and 615 controls would be required to detect this association with 80% power atan alpha level of 0.05.Conclusions. These findings suggest that the ER impairment reported in the depression literature exists across all basic emotions except sadness. The effect size, however, is small, and previous studies have been underpowered.