Associations between psychological flexibility and mental health problems during the Covid-19 pandemic: a three-level meta-analytic review

Many studies have indicated the negative associations between psychological flexibility (PF) and mental health problems (i.e., depressive, anxiety, and stress symptoms) during the COVID-19 pandemic, however, the associations revealed were inconsistent. This study aimed to summarize the primary literature quantitatively and provide better estimates of these associations. A systematic literature review was performed in six databases (finally yielding twenty-four studies) and three-level meta-analytic models were employed to synthesize effect sizes and to examine potential moderators of the associations between PF and depressive, anxiety, and stress symptoms. Our metaanalyses results revealed a moderate and significant association between PF and depressive (r = - 0.458, 95% CI [- 0.594; - 0.323], p < 0.001), anxiety (r = - 0.452, 95% CI [- 0.581; - 0.323], p < 0.001), and stress symptoms (r = - 0.443, 95% CI [- 0.666; - 0.221], p < 0.01). We found that the association between PF and stress symptoms is larger for males than for females, and that the associations between PF and symptoms of depression, anxiety, and stress differ by the type of measures that are used to assess PF, anxiety and stress symptoms. As a malleable protective factor, PF should be targeted in mitigating individuals' mental health problems during and after the COVID-19 pandemic.