26872
Psychiatric Comorbidity and Sex Bias in Adults with Autism Spectrum Disorder
Individuals with ASD frequently suffer from co-occurring psychiatric disorders with prevalence estimates ranging from 11-80%. The most commonly reported co-occurring psychiatric conditions are depression, obsessive-compulsive disorder (OCD), and anxiety. Psychiatric comorbidities provide accessible targets for intervention that can improve the quality of life of adults with ASD, necessitating an understanding of their prevalence rates in this population.
Objectives:
The aims of this study were to report the prevalence of co-occurring psychiatric conditions and the sex bias of comorbidity in a large sample of adults with ASD in comparison to a population-based control cohort.
Methods:
ASD case status (N=411) was determined by in-person assessments through ASD phenotyping protocols within the University of Utah Autism Research Program. ASD cases were matched to controls (N = 2055) within the Utah Population Database (UPDB) in a 1:5 ratio by age, sex, and duration of Utah residence (overall sample mean age = 31.14, range = 18-65; 87.1% male). Medical record diagnostic codes were used to identify the presence of co-occurring psychiatric disorders by linking cases and controls within the UPDB to diagnostic records from the two largest healthcare systems in Utah. Diagnostic codes were collapsed into the following categories: anxiety, OCD, depression, expansive mood, and schizophrenia. Chi-square analyses were used to compare the comorbidity frequency between cases and controls and between males and females within each cohort. Comparisons were considered statistically significant at the < 0.05 level.
Results:
The most common co-occurring psychiatric conditions in the ASD cohort were anxiety (47.4%), expansive mood (27.7%), and depression (18.0%). Comparison of psychiatric disorders between adults with and without ASD is provided in Table 1. Psychiatric conditions overall and categorically were significantly more prevalent in adults with ASD (p < 0.001).
Frequencies of psychiatric conditions were compared by sex within each cohort (Table 2). As expected, females in both cohorts experienced an increased rate of anxiety (ASD p = 0.021; control p = 0.015). Compared to their male counterparts, females in the control cohort, but not ASD cohort, experienced a significantly higher rate of depression (9.1% vs. 5.3%, p = 0.013; 18.9% vs. 17.9%, p = 0.861, respectively). Females in the ASD cohort had higher rates of OCD than males (28.3% vs. 15.9%, p = 0.027).
Conclusions:
These results confirm previous findings that adults with ASD experience increased rates of co-occurring psychiatric disorders, demonstrating the importance of identifying, and subsequently treating, these disorders in this population. Sex biases observed in the ASD cohort differed from the control cohort for depression and OCD. Psychiatric disorders commonly reported as having a male bias in the general population appeared in the context of ASD either equally between males and females (schizophrenia) or more commonly in females (OCD). Further in-person assessment is merited to characterize phenotypic and physiologic differences accompanying psychiatric comorbidity in adults with ASD.