Incidence of and factors associated with manic episodes and bipolar disorder in the decade following depression onset in Germany.

AIM: The goal of this retrospective cohort study was to analyze the incidence of and factors associated with manic episodes and bipolar disorder in the decade following a depression diagnosis in patients from Germany.

METHODS

This study included adults who were diagnosed with depression for the first time in one of 199 neuropsychiatric practices in Germany between 2007 and 2017 (index date). The cumulative incidence of a manic episode or bipolar disorder was estimated for up to 10 years after the index date using Kaplan-Meier curves. Multivariate Cox regression models were further used to investigate the association between demographic, clinical, and pharmaceutical variables and the incidence of manic episodes and bipolar disorder.

RESULTS

This study included 162,689 patients [mean (standard deviation) age 51.6 (14.9) years; 63.2% women]. Ten years after a depression diagnosis, the incidence of manic episodes and bipolar disorder ranged from 2.9% to 5.1%. Young age, severe depression, and the prescription of venlafaxine were identified as variables positively associated with manic episodes and bipolar disorder, while several clinical (e.g., somatoform disorders, extrapyramidal and movement disorders) and pharmaceutical variables (e.g., hypericum perforatum, amitriptyline) were negatively associated with bipolarity.

CONCLUSIONS

The incidence of manic episodes and bipolar disorder was relatively low in the decade following a depression diagnosis in Germany. Young age, depression severity, and several clinical and pharmaceutical variables were significantly associated with bipolarity in patients with depression.