Psychiatric co-morbidities are shown to be very prevalent in patients diagnosed with Autism Spectrum Disorder (ASD), up high to 53% for mood, 50% anxiety and 43% for ADHD disorders in an European cohort of adults with HFA. Using a new approach, our study proposes to explore aspects of co-morbidities in the largest French cohort of HFA adults (C0733/InfoR) by implying qualitative and quantitative clinical tools.

To explore: (1) the prevalence rates of psychiatric co-morbidities; (2) the interplay between co-morbidities and the ASD symptoms.

Diagnosis was made according to DSM 5 criteria. Dimensional evaluation used Social Responsiveness Scale (SRS), Systemizing Quotient (SQ) and Empathy Quotient (EQ). We used T-test, Mann–Whitney test and linear regression models.

We included 103 patients (mean age 29.3, sex ratio M/F: 3.4:1). Lifetime prevalence rates of 53.5% for depressive disorder 73.5% for anxiety disorders and 37.5% for ADHD were found. Subjects with psychotic co-morbid symptoms had a more severe social deficit (SRS score 66.2 vs 77.9 P<0.05); patients with ADHD, lower cognition (mean IQ total 107.7 vs 99.0 P<0.05). SQs (P<0.05) were significantly higher in patients with co-morbid psychosis, dysthymia, suicide attempts, and depressive disorders and directly correlated with age (β=0.35, P<0.05). SQ and EQ were inversely correlated.

The results reproduce the high prevalence of co-morbidities in other studies and explore its association with social functioning and cognition. Identification of associated psychiatric conditions in subjects with HFA is therefore a crucial clinical issue potentially guiding the treatment.