Age of onset of bipolar disorder: Association with lifetime psychiatric disorders and health-related quality of life

INTRODUCTION: Bipolar Disorder (BD) is common in children, adolescents and adults. Early-onset BD has been associated with a more severe clinical course and greater long-term impairment. However, the specific associations between age of onset (AOO), lifetime comorbidities and health-related quality of life (HRQOL) remain unclear. METHODS: We analyzed data from NESARC III, a representative U.S. sample, and conducted both cross-sectional and retrospective cohort analyses. This study included 1044 participants with a history of BD. Participants were categorized into 3 AOO groups: childhood (< 13 years), adolescence (13-18 years) and adult (> 18 years). Sociodemographic characteristics, lifetime psychiatric disorders according to DSM-5 criteria and HRQOL were compared across groups. RESULTS: Childhood-onset BD was reported by 19.83% of participants, adolescence-onset by 21.65%, and adult-onset by 58.52%. Compared to the adult-onset group, the childhood onset group had higher rates of suicide attempts (AOR = 4.30; 95% CI = 2.65-6.98), drug use disorder (AOR = 2.16; 95% CI = 1.46-3.20) and panic disorder (AOR = 3.17; 95% CI = 1.93-5.20). They also showed significantly lower HRQOL scores, including both the Physical Disability scale (p < 0.001) and the Mental Disability scale (p < 0.001) indicating worse health. A severity gradient was observed across childhood-, adolescence- and adult-onset groups. CONCLUSION: Experiencing BD during childhood or adolescence is associated with higher lifetime psychiatric disorder prevalence and poorer HRQOL in adulthood. These results underscore the importance of prevention, early diagnosis and timely treatment of BD in youth to improve long-term outcomes.