Attention deficit/hyperactivity disorder symptoms in Italian bipolar adult patients: a preliminary report

Background: It has been recently suggested that bipolar disorder (BD) with comorbid ADHD represents a distinct clinical phenotype of BD. With the aim to assess the impact of ADHD symptoms, we investigated the prevalence, epidemiological and clinical features associated with such a comorbidity in a sample of adult BD patients.

Methods: A total of 96 outpatients (aged 18-65 years) with BD were included. All patients were screened using the Adult ADHD Self-report Scale (ASRS) and the Diagnostic, Clinical and Therapeutic Checklist (DCTC), a semi-structured interview developed for systematic collection of familial, demographic, anamnestic and clinical informations and exploration of DSM-IV-TR diagnostic criteria for mood, anxiety, eating, impulse control and alcohol and substance use disorders. The DCTC also includes the Clinical Global Impression Bipolar scale (CGI-BP), the Global Assessment of Functioning scale (GAF) and the Sheehan Disability Scale (SDS).

Results: In our sample, 19 (19.8%) out of 96 BD patients fulfilled ASRS criteria for current and lifetime (onset before 7 years of age) ADHD symptoms (ADHD+). Compared to BD probands without ADHD symptoms (ADHD-), ADHD+ patients showed higher rates of current mixed episode, and lower rates of mania. ADHD+ resulted in more severe mean scores on the CGI-BP mixed, depressive and global subscales. None of the ADHD+ patients were in remission of BD at the time of the evaluation, versus 24 (31.2%) of the ADHD- group. ADHD+ patients also reported higher rate of lifetime comorbidity with Substance Use Disorder (SUD) and Alcohol Abuse in comparison to ADHD- patients. In particular the different rate in substance abuse was related to cocaine and poly-drug abuse. The two groups did not report significant differences in functioning and social adjustment with the exception of familial adjustment that was more compromised in ADHD+ than in ADHD- patients.

Limitations: Retrospective design and limited sample size.

Conclusions: In ADHD+ patients, BD is associated with higher rate of mixed states, more severe psychopathology and more impaired familial functioning as well as higher rates of comorbid substance, alcohol and poly-drug abuse compared to BD patients without adult ADHD. Our findings suggest that ADHD symptoms in adults may influence clinical presentation, course and prognosis of BD. Further prospective research is needed to confirm our findings and to explore treatment implications for the management of BD.