Autism in a general adult mental health service in Ireland: prevalence, clinical presentation, and service use

BACKGROUND: Autistic adults experience high rates of co-occurring mental health difficulties, yet little is known about their representation within secondary adult mental health services. This study aimed to examine the actual prevalence and clinical presentation of autistic adults attending a community general adult mental health service in Ireland. METHODS: A cross-sectional retrospective chart review was conducted in July 2023 within a community-based secondary mental health service serving a population of 92,610. Demographic characteristics, autism-related factors, diagnoses, self-harm/suicidality, and multidisciplinary service utilisation were extracted and analysed using descriptive and inferential statistics. RESULTS: Forty autistic service users were identified among a total caseload of 1,270 (3.1%). The median age was 23 years, and 67.5% were male. Most autism diagnoses (65%) were made through Child and Adolescent Mental Health Services. Psychotic disorders were the most common psychiatric diagnosis (30%), followed by mood and anxiety disorders. Over half (52.5%) had a history of self-harm and/or suicidality, and 17.5% had required psychiatric inpatient admission. Although 95% were referred to at least one multidisciplinary team (MDT) service, 30% did not attend these appointments. CONCLUSIONS: Autistic adults represented a small proportion of service users despite their high burden of mental health difficulties, suggesting possible underrecognition of autism and barriers to accessing secondary mental health services. Those receiving care demonstrated complex clinical needs, including high rates of psychosis and suicidality. Improving autism recognition, developing integrated care pathways, and adapting multidisciplinary services to better meet autistic adults' needs are essential to delivering equitable mental healthcare.