Comorbidity between attention deficit hyperactivity disorder (ADHD) and bipolar disorder in a specialized mood disorders outpatient clinic

Background Comorbidity between ADHD and Bipolar Disorder (BD) is associated with greater severity of BD. The current study aims at investigating, in a specialized mood disorders clinic, the percentage of comorbid ADHD-BD subjects and assessing the impact of ADHD on the severity of BD. Methods Out of 539 mood disorders subjects, the medical records of 138 BD subjects were scrutinized in terms of their clinical and demographic characteristics, and their scores at the Adult ADHD Self-Report Scale (ASRS-v1.1) Symptom Checklist were logged. Those positively scoring at the ASRS-v1.1 underwent clinical assessment by a senior psychiatrist specialized in ADHD. Comorbid ADHD-BD subjects were then compared with BD sufferers without ADHD. Results Sixty-three (45.65%) of the participants were screened positive at the ASRS-v1.1. 49 were clinically assessed for the presence of ADHD. Only 27 (55%) received a diagnosis of ADHD. Comorbid ADHD-BD subjects were found to be younger at the onset of BD, showed higher numbers of depressive episodes, more anxiety and substance use disorders, more borderline personality traits and greater cyclothymic temperament. Comorbid BD-ADHD subjects reported more childhood emotional abuse. Limitations Some subjects were unreachable and thus not clinically assessed for ADHD. Conclusions More than 20% of BD subjects were suffering from ADHD. The comorbidity of the two disorders was associated with worse outcomes, possibly resulting from stressful early-life events. More than 40% of the subjects who scored positively at the ASRS-v1.1 did not suffer from ADHD, which suggests that this scale should be used with caution in BD subjects.