The course of bipolar disorder as a function of the presence and sequence of onset of comorbid alcohol use disorders in outpatients attending the Fondamental Advanced Centres of Expertise.

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