The prevalence, odds and predictors of lifespan comorbid eating disorder among people with a primary diagnosis of bipolar disorders, and vice-versa: Systematic review and meta-analysis.

BACKGROUND

There are scarce and discrepant data about the prevalence and correlates of co-occurring eating disorders (EDs) among people with a primary diagnosis of bipolar disorder (BD), and vice-versa, compelling a systematic review and meta-analysis on the matter.

METHODS

MEDLINE/PsycINFO databases were systematically searched for original studies documenting BD⇌ED comorbidity across the lifespan, from inception up until April 20, 2020. Random-effects meta-analysis and meta-regression analyses were conducted, accounting for multiple moderators.

RESULTS

Thirty-six studies involved 15,084 primary BD patients. Eleven studies encompassed 15,146 people with primary EDs. Binge eating disorder (BED) occurred in 12.5% (95%C.I.=9.4-16.6%, I=93.48%) of BDs, while 9.1% (95%C.I.=3.3-22.6%) of BEDs endorsed BD. Bulimia Nervosa (BN) occurred in 7.4% (95%C.I.=6-10%) of people with BD, whereas 6.7% (95%C.I.=12-29.2%) of subjects with BN had a diagnosis of BD. Anorexia Nervosa (AN) occurred in 3.8% (95%C.I.=2-6%) of people with BDs; 2% (95%C.I.=1-2%) of BD patients had a diagnosis of AN. Overall, BD patients with EDs had higher odds of being female vs. non-ED controls. Several moderators yielded statistically significant differences both within- and between different types of BDs and EDs.

LIMITATIONS

Scant longitudinal studies, especially across different EDs and pediatric samples. High heterogeneity despite subgroup comparisons. Limited discrimination of the quality of the evidence.

CONCLUSIONS

The rates of BD⇌ED comorbidity vary across different diagnostic groups, more than they do according to the "direction" of BD⇌ED. Further primary studies should focus on the risks, chronology, clinical impact, and management of the onset of intertwined BD⇌ED across different ages, promoting a continuum approach.