Abstract
Objectives: The comorbidity of alcohol use disorder (AUD) and bipolar disorder (BD) has been repeatedly associated with poorer clinical outcomes than BD without AUD. We aimed to extend these findings by focusing on the characteristics associated with the sequence of onset of BD and AUD. Methods: 3,027 outpatients from the Fondamental Advanced Centres of Expertise were ascertained for BD-1, BD-2 and AUD diagnoses, including their respective ages at onset (AAOs, N =2,804). We selected the variables associated with both the presence and sequence of onset of comorbid AUD using bivariate analyses corrected for multiple testing to enter a binary regression model with the sequence of onset of BD and AUD as the dependent variable (AUD first - which also included 88 same-year onsets, vs. BD first). Results: BD patients with comorbid AUD showed more severe clinical profile than those without. Compared to BD-AUD (N =269), AUD-BD (N =276) was independently associated with a higher AAO of BD (OR =1.1, p <0.001), increased prevalence of comorbid cannabis use disorder (OR =2.8, p <0.001) a higher number of (hypo)manic/mixed BD episodes per year of bipolar illness (OR =3, p <0.01). Limitations: The transversal design prevents from drawing causal conclusions. Conclusion: Increased severity of BD with AUD compared to BD alone did not differ according to the sequence of onset. A few differences, though, could be used to better monitor the trajectory of patients showing either one of these disorders.