Association of pediatric bipolar disorder and substance use disorder in adulthood in a prospective cohort

Background: Patients with pediatric bipolar disorder (PBD) have high risk of adolescent substance use disorders (SUD). Less is known about the risk of SUD into adulthood. This study analyzed the longitudinal associations between pediatric onset bipolar disorder and SUD from adolescence to adulthood. Methods: Psychopathology was assessed prospectively in controls (HC) (N = 53), participants with ADHD (N = 33), and participants with PBD (N = 110) at up to 12 waves (ranging from 6-month to 2-year intervals), and at 25-year follow-up(HC = 39, ADHD = 18, PBD = 53). Logistic regressions were used to assess the effect of PBD on risk for SUD in adulthood. Results: Participants with PBD (mean age 22.58) had 6.53 (CI 2.15–19.83, p < 0.001) times the odds of having adult SUD during the 12-year follow-up compared to HC (mean age 22.46) participants and 2.9 (CI 1.05–8.02, p = 0.040) times the odds than those with ADHD without PBD (mean age 21.59). At 25-year follow-up, PBD diagnosis was positively associated with having SUD in adulthood compared to the HC group (OR 6.42, p < 0.001), but was not different than the ADHD group (mean age PBD = 35.49, ADHD = 34.68, HC = 35.29). Number of life events mediated the relationship between PBD and SUD in adulthood. Conclusion: PBD is strongly associated with increased odds of SUD in early adulthood when compared to participants with ADHD and HC, though the differences between those with PBD and ADHD may not persist over time. Understanding the increased odds of SUDs in those with PBD provides an opportunity for intervention and for decreasing morbidity related to PBD.