Psychiatric comorbidity in persons with high-functioning autism spectrum disorders: Findings from a tertiary care neuropsychiatric hospital

Background: The literature on co-morbid psychiatric illnesses in adults with high-functioning autism (HFA) spectrum disorder is sparse. Purpose: To examine the nature of psychiatric comorbidity and treatment response in adults with HFA spectrum disorder. Materials and Methods: Case records of subjects (age >= 17 years) who presented over a period of 16 years with primary psychiatric symptoms and further detected to have an HFA spectrum disorder, were analyzed. Autism spectrum disorders (ASD) along with near normal to normal verbal communication and general intelligence were considered as HFA spectrum disorders. Results: 33 subjects met the study criteria. Nine subjects (27%) were diagnosed to have an underlying Asperger's syndrome and the rest 24 (73%) had pervasive developmental disorders unspecified (PDD NOS). None of the subjects were diagnosed to be suffering from ASD prior to the visit to our hospital. Mean age a the time of psychiatric consultation was 22.7 (s.d = 4.8) years and mean age a the onset of psychiatric comorbidity was 16.48 (s.d = 4.4) years. Nearly half of the sample had more than one type of psychiatric illness. Most common lifetime psychiatric diagnosis was obsessive-compulsive disorder (OCD) (n =16, 48.4%). Bipolar disorder (BD) was the second most common type of psychiatric manifestation (n =13, 39.3%) followed by psychotic spectrum disorders (n =9, 27.2%). Overall response to treatment was minimal. Conclusions: Individuals with HFA spectrum disorders suffer from multiple psychiatric comorbidities. OCD is the most common type of psychiatric comorbidity followed by BD and psychotic spectrum disorders. Comorbid psychiatric illnesses in individuals with HFA show poor response to treatment.