Diagnostic profiles of adult psychiatric outpatients with and without attention deficit hyperactivity disorder

Despite growing recognition that attention deficit/hyperactivity disorder (ADHD) is a highly prevalent, impairing, and comorbid disorder that persists into adulthood, reports on the nature and extent of its psychiatric comorbidities have been mixed to date. This study compared the prevalence rates of all major Axis I disorders as well as borderline personality disorder in an unselected sample of adult psychiatric outpatients with and without ADHD.

As part of the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project, we administered a DSM-IV-based semi-structured diagnostic interview assessing ADHD and other psychiatric disorders to 1134 patients presenting for initial evaluation at an outpatient psychiatric practice. Logistic regression analyses were used to compare the rates of each disorder in patients with versus without an ADHD diagnosis (both overall and by Combined and Inattentive type).

Patients with (versus without) any ADHD diagnosis had significantly higher rates of bipolar disorder, social phobia, impulse control disorders, eating disorders, and BPD, and significantly lower rates of major depressive disorder and adjustment disorder (all p<.05). Patients with (versus without) ADHD-Inattentive type had significantly higher rates of social phobia and eating disorders, whereas those with (versus without) the ADHD-Combined type had significantly higher rates of bipolar disorder, alcohol dependence, and BPD (all p<.05).

In this novel investigation of the psychiatric profiles of an unselected sample of treatment-seeking adult outpatients with versus without ADHD, a distinct pattern of comorbidities emerged across subtypes, with implications for the accurate assessment and treatment of patients presenting for psychiatric care.