Patients with bipolar disorders (BPD) display high rates of comorbidities, especially substance abuse (20-40%) and attention deficit/hyperactivity disorder (ADHD) (6%-20%). However, there are virtually no data evaluating the role of current ADHD on the global functioning of patients with BPD. The recent literature suggests that impairments in quality of life are a key prognostic feature for predicting the long course of BPD. The aim of this study was to investigate the intrinsic impact of adult ADHD and substance abuse in patients with BPD on levels of social adaptation, functioning and vitality. Seventy-three outpatients with BPD I or II, all euthymic and being treated with mood stabilizers, were evaluated using the following measures: 1) the Diagnostic Interview of Genetics Study for DSM-IV criteria; 2) the ADHD Self-Report Scale (ASRS) (screening of adult ADHD); 3) measures of quality of life: social adaptation (Social Adjustment Scale Self-Report (SAS-SR)), well-being (Short Form 36 (SF-36) Health Survey), and the Brief Psychiatric Rating Scale. In this clinical sample, 30% met the ADHD criteria and 22% were substance abusers. The results showed that the presence of ADHD in BPD patients significantly predicted a low social functioning and adaptation by comparison with BPD patients without ADHD. By contrast, we failed to detect a significant impact of substance abuse on those functional outcomes. This is the first step towards improved screening for comorbidities and an understanding of their crucial role in the prognosis of the disorder, as well as in defining new multilevel therapeutic strategies.