Health and social characteristics of autistic adults in the UK-wide Adult Autism Spectrum Cohort (ASC-UK): A cross-sectional study

Purpose This study aimed to characterise the health, social, and demographic circumstances of autistic adults in the UK using data from the Adult Autism Spectrum Cohort-UK (ASC-UK), a large, cross-sectional, population-based cohort. It sought to identify age- and gender-related differences in mental and physical health, healthcare access, employment, social relationships, and support needs. Methods Between 2015 and 2021, 2129 autistic adults (diagnosed or self-identified), aged 16 years and older, were recruited via diverse routes including NHS services and community organisations. Data were collected using a 78-item registration questionnaire covering ten domains of daily life and the Social Responsiveness Scale-2 (SRS-2). Responders were grouped into four age categories and compared using appropriate statistical tests including ANOVA, Kruskal-Wallis, Chi-square, and effect size measures. Results Autistic adults reported high rates of physical (e.g., gastrointestinal, obesity, arthritis) and mental health conditions (e.g., anxiety, depression), with notable gender and age variation. Females reported significantly more mental and physical health issues than males. Employment was lowest in the youngest and oldest groups and unemployment was associated with poor mental health. A substantial gap was found between needed and received support, particularly among females and those with complex health needs. Social deprivation was not significantly associated with health diagnoses. Conclusion Autistic adults across the UK experience substantial health disparities and unmet support needs. Gender and age influence outcomes, and healthcare services must adapt to improve access and equity. This study offers critical, lifespan-wide insights to inform policy, practice, and future longitudinal research.