Identifying bipolar disorders in individuals with intellectual disability

Objective The aim of the present study was to characterize adults with intellectual disability (ID) and concomitant clinical diagnoses of bipolar disorder (BPD), and determine whether DSM‐IV criteria would distinguish individuals with BPD from patients with other psychiatric diagnoses. Methods A retrospective chart review was done of a convenience sample of adult patients seen over a 3‐year period in a specialty clinic for adults with ID and psychiatric disorders. The DSM‐IV criteria were used to differentiate individuals with clinical symptoms of BPD from groups of patients with other mood or thought disorders with behavioural symptoms which frequently overlap those of BPD. Behavioural symptoms were also catalogued and used to distinguish the diagnostic groups. Results Subjects with clinical symptoms of BPD had significantly more DSM‐IV mood‐related and non‐mood‐related symptoms, as well as functional impairments, compared to individuals with major depression, depression with psychosis or schizophrenia/psychosis NOS (not otherwise specified). Likewise, behavioural profiles of the BPD group of patients differed significantly from patients in the other three groups. Conclusions Bipolar disorder can be readily recognized and distinguished from other behavioural and psychiatric diagnoses in individuals with ID, and DSM‐IV criteria can be useful in the diagnosis of BPD.