Background Autistic people experience an increased risk of a wide range of adverse outcomes across many domains, impacting all aspects of daily life. While individual reviews have explored specific outcome areas, a comprehensive cross-domain synthesis is lacking. Because the evidence spans diverse outcome types and review designs, a narrative umbrella synthesis is needed to integrate findings across heterogeneous reviews and provide a broader systems-level overview. Methods This umbrella review identified and synthesised published systematic, meta-analytic, and narrative reviews on the outcomes associated with autism. Five databases were searched from inception to June 2024. Dual screening and multi-reviewer data extraction were conducted, and methodological quality was appraised using established review tools. Findings were aggregated using inductive narrative synthesis, with domain grouping and thematic classification determined by consensus among reviewers. Results Of 13,841 records identified, 134 reviews met inclusion criteria. Outcomes were grouped into three organisational domains: mental health, physical health, and social and lifestyle. The most consistently reported adverse outcomes included anxiety and mood disorders, suicidality and self-harm, eating and psychotic disorders, sleep problems, epilepsy, gastrointestinal and feeding difficulties, obesity, oral health problems, increased mortality risk, victimisation and bullying, reduced quality of life, loneliness, relationship difficulties, and unemployment. Evidence strength varied across outcomes, but elevated risk patterns were reported across multiple independent reviews. Discussion Adverse outcomes for autistic people affect multiple areas of life. This umbrella synthesis identifies the principal outcome clusters supported by review-level evidence and highlights research, clinical practice, and service planning priorities. Systematic Review Registration https://www.crd.york.ac.uk/prospero/ , identifier CRD42023475389.
French et al. (Mon,) studied this question.