Background
A large number of psychiatric comorbidities contributes to the heterogeneity and complexity of autism spectrum disorders (ASDs). Coexisting psychiatric disorders in subjects with normal intelligence ASDs include attention deficit and hyperactivity disorder (ADHD), chronic tic disorders, and mood and anxiety disorders. Additionally, besides DSM Axis I conditions, cluster A and C personality disorders (PD), in particular schizoid, schizotypal and obsessive-compulsive personality disorders (OCPD) have been reported. However, the literature on this topic remains scarce. The aim of our preliminary investigation was to estimate the frequencies of DSM-IV axis I and II diagnoses and explore the psychosocial and occupational functioning in a group of ASDs adults with normal-intelligence consecutively referred to our centre.
Methods
Participants were at least 16 years of age with possible highfunctioning (HF) ASDs referred to the Pavia Autism Laboratory (University of Pavia) or the Neuropsychiatry Unit of the Milan San Paolo Hospital. HF ASDs diagnostics included ADI-R, ADOS module 4, WAIS-R. The MINI Plus and the SCID-II were administered to investigate psychiatric comorbidities. The severity of anxiety and depression symptoms was quantified with HAMA and HRSD. Social, occupational, and psychological functioning was rated using GAF.
Results
Twenty-one subjects, 16 males (76%) and 5 females (24%), from 17 to 45 years of age (mean 27.57 ± 10.08 years) were included. 71% of subjects presented one or more Axis I disorders; the most common comorbidity was mixed anxiety-depressive disorder, followed by generalized anxiety disorder, dysthymic disorder, panic disorder, major depressive disorder, social phobia, obsessive-compulsive disorder, bipolar II disorder and brief psychotic disorder. 66% of subjects had one or more personality disorders. 66% of Axis II comorbidity was represented by Cluster C PDs, 25% by Cluster A PDs and 9% by negativitistic and depressive PDs. No Cluster B PDs was detected. A correlation between age and number of comorbidities was detected.