Lifetime prevalence of psychiatric comorbidities in patients with bipolar disorder: A systematic review and meta-analysis.

Background: Bipolar disorder (BD) is a severe psychiatric disease and part of its burden is related to the high rates of lifetime psychiatric comorbidity (PC), with diagnostic, therapeutic, and prognostic implications.

Methods: Registered in PROSPERO (CRD42021282356). Meta-analyses were performed, searching for relevant papers published from 1993 to 2022 in Medline/PubMed (including E-Pub Ahead of Print), Embase, Cochrane Library (Central), PsycINFO, Scopus, Web of Science and via hand-searching, without language restrictions. 12.698 studies were initially identified, 114 of which were ultimately chosen based on the eligibility criteria. We performed two meta-analyses (prevalence and risk ratio) of mental health conditions among subjects with BD and then conducted a comprehensive examination of moderator effects using multivariable meta-regression models for moderators identified as significant in the univariable analysis.

Findings: Overall PC prevalence of at least one disorder was 38.91 % (95 % CI 35.24-42.70) and the most frequent disorders were: anxiety (40.4 % [34.97-46.06]), SUD (30.7 % [23.73-38.73]), ADHD (18.6 % [10.66-30.33]) and Disruptive, impulse-control and conduct disorder (15 % [6.21-31.84). The moderators with higher association with individual prevalences were UN's Human Development Index (HDI), female gender, age, suicide attempt, and age at onset (AAO).

Interpretation: It becomes evident that the prevalence of PC among individuals with BD is notably high, surpassing rates observed in the general population. This heightened prevalence persists despite significant heterogeneity across studies. Consequently, it is imperative to redirect clinical focus towards comprehensive mental health assessments, emphasizing personalized and routine screening. Additionally, there is a pressing need for the enhancement of public policies to create a supportive environment for individuals with BD, ensuring better therapeutic conditions and sustained assistance. By addressing these aspects, we can collectively strive towards fostering improved mental health outcomes for individuals with BD.