Differential diagnosis of ADHD and bipolar disorder : an analogue study

Bipolar disorder (BD) and attention deficit/hyperactivity disorder (ADHD) share an overlapping number of symptoms. These shared symptoms may result in the misdiagnosis or over diagnosis of these two disorders. The purpose of this study was to look at the diagnostic practices of clinicians and clinicians-in-training to see what diagnosis they would give to a hypothetical patient who presents with ambiguously ADHD and bipolar disorder symptoms. Clinicians and clinicians-in-training (N = 40) read two vignettes, one child and one adult, where the patient presented with both ADHD and BD overlapping symptoms, and then were asked to provide one primary DSM-IV diagnosis, rule-outs, and three follow up questions. The results show that the age of the client in the vignette significantly affected the diagnosis that the client received. Across vignettes, the child client was 2-6x more likely to receive a BD diagnosis and the adult was 2-4x more likely to receive an ADHD diagnosis. The diagnosis pattern in this study is opposite the relative prevalence rates, where adults are more likely to meet criteria for BD and children for ADHD. Additionally, almost two-thirds acknowledged that the diagnosis could be either ADHD or bipolar, but only about one-third asked follow-up questions that help in the differential diagnosis of ADHD and bipolar based on the overlapping symptoms included. These results suggest that clinicians should pay more attention to the chronic/episodic nature of symptoms and if they differ from the patient’s normal state or if they are trait-like