Mindfulness-based and mindfulness-informed interventions in bipolar disorder: A meta-analysis based on Becker's method.

Bipolar disorder is a highly disruptive and debilitating problem. Mindfulness-based and mindfulness-informed interventions have exponentially emerged as third-generation therapies, applied to a wide spectrum of disorders, including bipolar disorder. However, the reviews and meta-analyses published to date are limited in their conclusions, as they are based on single-group pretest-posttest cohort designs and mostly focused on mindfulness-based interventions. The present review and meta-analysis try to address these limitations, including studies on informed mindfulness, controlled and single-group designs. It used a specific meta-analytical procedure that allows an imputation procedure in those designs lacking a comparison group, by means of separate omnibus tests for the experimental and control group. A total of 13 studies (N = 331) were selected. The results showed an absence of effects on depression (g = 0.21) and mania (g = -0.13), but significant moderate effect on anxiety (g = 0.53). In conclusion, both mindfulness interventions showed robust evidence on anxiety symptoms in pretest-posttest periods compared to control groups. Few studies and lack of evidence of follow-up periods were the main limitations found.