The association between positive affect and depressive symptoms in individuals with diagnosed or probable major depressive disorder: A systematic review and meta-analysis.

BACKGROUND

A number of theories propose that positive affect is negatively associated with depressive symptoms, but this claim has only been examined in meta-analyses of non-clinical samples and it remains unclear whether the association holds in clinical populations.

OBJECTIVE

To obtain evidence-based estimates of the cross-sectional and prospective associations between positive affect and depression severity measures in individuals with clinical depression by conducting a systematic review and meta-analysis.

METHODS

We performed a systematic search on PsychINFO, MEDLINE, and Google Scholar and included studies reporting estimates of the association between positive affect and depressive symptoms in clinical populations. A correlational (r) effect size based on cross-sectional measures was estimated using a random-effects meta-analysis.

RESULTS

From 1,930 unique records, we identified 17 eligible manuscripts, reporting 20 effect sizes from 1,665 individuals with diagnosed or probable major depressive disorder. The results of the omnibus model indicated a significant moderate association between cross-sectional positive affect and depressive symptoms (r = -.38, 95 % CI [-0.45, -0.30]); heterogeneity of effect sizes was low to moderate (I2 = 45.79 %). None of the included studies reported prospective relationships between the variables outside of a treatment context.

CONCLUSION

The results are in line with theoretical models on the cross-sectional association between positive affect and depressive symptoms in major depressive disorder. More research is needed to develop a deeper understanding of the overlap and temporal directions between positive affect and depressive symptoms in clinical populations.