Psychopathology: differences among adults with intellectually disabled, comorbid autism spectrum disorders and epilepsy.

The goal of this study was to systematically examine group differences among adults with intellectual disabilities (ID), comorbid autism spectrum disorders (ASD), and epilepsy through a detailed exploration of the characteristics that these disorders present in the area of psychopathology. Previous studies indicating that individuals with ID have comorbid ASD and epilepsy tend to stop short of addressing these disorders' impact on the full range of psychosocial issues, particularly in adult samples. Assessment of psychopathology was made with the ASD-comorbidity-adult version (ASD-CA). One hundred participants, with ID held constant, were matched and compared across four equal groups comprising 25 participants with ID, 25 participants with epilepsy, 25 participants with ASD, and 25 participants with combined ASD and epilepsy. When controlling for age, gender, race, level of ID, and hearing and visual impairments, results of the MANOVA revealed significant differences among groups, Wilks's Lambda=.76, F(15, 254)=1.82, p<.05, eta(2)=.09. A one-way ANOVA was conducted for each of the five subscales of the ASD-CA as follow-up tests to the MANOVA. Groups differed significantly Anxiety/Repetitive Behavior subscale, F(3, 96)=2.93, p<.05, eta(2)=.08, Irritability/Behavior excess subscale, F(3, 96)=4.74, p<.01, eta(2)=.13, Attention/Hyperactivity subscale, F(3, 96)=5.18, p<.01, eta(2)=.14, and Depressive Symptoms subscale, F(3, 96)=3.73, p<.01, eta(2)=.10. Trend analysis demonstrated that individuals with ID expressing combined comorbid ASD and epilepsy were significantly more impaired than the control group (ID only) or groups containing only a single comorbid factor with ID (ASD or epilepsy only). Implications of these findings elucidate the nature of these disorders and their influence on patient care and management.