Association Between Autism and PTSD Among Adult Psychiatric Outpatients

Autism Spectrum Disorder (ASD) occurs in 1-1.5% of the general population and possibly in up to 20% of psychiatric outpatients. Post Traumatic Stress Disorder (PTSD) occurs at some point in life in 4% of the general population and in 14–20% of psychiatric outpatients. Knowledge about how PTSD manifests in people with ASD is important in order for it to be correctly diagnosed and intervened for.

This study investigated the relationship between PTSD and autism among adult psychiatric outpatients (N = 90) of whom 63 had ASD or subthreshold ASD based on DSM-5 criteria. The study group was subjected to in-depth psychiatric assessments using validated instruments. Diagnosis of PTSD was made based on the Mini International Neuropsychiatric Interview (MINI).

There was a trend towards PTSD being more common among participants with ASD compared to participants without ASD, although significant differences could not be shown in this small sample. 21% of the ASD group had current PTSD, compared to 4% of the study group without ASD. There were no differences between the groups regarding exposure to trauma. There was a trend towards a relationship between number of autism symptoms and hyperarousal symptoms in PTSD. Conversely, the PTSD symptom of irritability/outbursts of anger, was significantly associated with number of autism symptoms.

A subgroup of psychiatric outpatients with ASD also suffer from PTSD. Hyperarousal symptoms are possibly more prevalent in the presentation of PTSD in individuals/patients with ASD compared to those without ASD.