Summary: A comprehensive review from King’s College London finds that the vast majority of autistic adults over 40 in the UK remain undiagnosed, leaving them exposed to significant health and social disadvantages. The study reports that older autistic adults are at higher risk for a wide range of physical and mental health conditions, including early-onset dementia and elevated rates of suicidal thoughts and self-harm.
The review also highlights persistent barriers to accessing appropriate healthcare, widespread social isolation, and reduced quality of life for many older autistic people. Researchers call for tailored health services, stronger social support systems, and long-term studies to understand ageing in autism better and to improve outcomes.
Key Facts
- Undiagnosed Majority: An estimated 89% of autistic adults aged 40–59 and 97% of those aged 60+ are undiagnosed in the UK.
- Severe Health Risks: Findings indicate up to four times higher risk of early-onset dementia and six times higher risk of suicidal ideation among older adults with elevated autistic traits.
- Life Expectancy Gap: Average life expectancy in the reviewed data is about six years lower for autistic adults than for non-autistic peers.
Source: King’s College London
Undiagnosed older autistic adults are a large, overlooked group
The Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London led the largest review to date on ageing across the autism spectrum. The authors re-analysed UK healthcare record studies and estimated that most autistic adults aged 40 and over have not been formally identified or offered autism-specific support. This diagnostic gap is largely generational: while diagnostic rates have risen in younger groups, older cohorts were less likely to be identified in childhood or adulthood.
Dr Gavin Stewart, the lead author and a British Academy Postdoctoral Research Fellow at the IoPPN, states that such high underdiagnosis means many autistic adults have never been recognised and therefore have not received appropriate interventions. He warns that this oversight likely increases vulnerability to isolation and preventable health problems and has skewed the research evidence base by excluding a substantial portion of the autistic population.
Greater prevalence of physical and mental health conditions
The review synthesised a broad set of studies and concluded that autistic people in midlife and later life face higher rates of almost every major health category compared with non-autistic adults of the same age. The elevated health burdens reported include immune and cardiovascular diseases, neurological and gastrointestinal disorders, anxiety and depression, and age-associated conditions such as Parkinson’s disease, osteoporosis and arthritis.
Particularly alarming are findings around mental health and cognitive decline: older adults with pronounced autistic traits showed up to six times higher odds of suicidal ideation and self-harm, and autistic adults were reported to have roughly four times the likelihood of early-onset dementia in the assembled studies. The review also reports an average life expectancy gap—autistic adults lived to about 75 years on average versus 81 years for non-autistic adults—though the authors caution these figures may be distorted by underdiagnosis in older people.
Researchers emphasise that autistic adults often face systemic barriers when seeking healthcare. Factors related to autistic traits—such as differences in communication and heightened sensory sensitivities—interact with service-level issues like limited clinician awareness of autism in adulthood, uncertainty about which services to use, and disrupted continuity of care.
Outside of health outcomes, the review documents poorer results across employment (before retirement), social relationships and overall quality of life. High levels of social isolation are common, and the evidence suggests that stronger social support correlates with better wellbeing for older autistic adults.
Professor Francesca Happé, Professor of Cognitive Neuroscience at the IoPPN and co-author of the review, emphasises the need for a lifespan approach: long-term research funding, autism-informed healthcare across adult services, and expanded social supports so autistic people can age with dignity, health and social connection.
Gaps in the evidence and priorities for future research
Although research on ageing in autism has grown in recent years, the review notes a persistent shortage of longitudinal studies that follow autistic people over time to measure ageing-related changes directly. Since only a small fraction of autism research historically has focused on midlife and older adults, the authors call for more studies that include diagnosed and trait-based samples, investigate transitions such as retirement and menopause, and examine interventions to reduce health disparities and social exclusion.
About this autism research news
Author: Franca Davenport
Source: King’s College London
Contact: Franca Davenport – King’s College London
Image: The image is credited to Neuroscience News
Original Research: Closed access.
“Ageing across the Autism Spectrum – A narrative review” by Gavin Stewart et al. Annual Review of Developmental Psychology
Abstract
Ageing across the Autism Spectrum – A narrative review
Aging in autistic populations has been historically overlooked but is now receiving growing attention. This narrative review offers a comprehensive overview of current evidence on ageing in autism by synthesising and critically appraising findings across research priorities identified by autistic people and other stakeholders.
Key topics covered include: (a) the trajectory of core autistic features across adulthood; (b) health profiles, biological ageing markers, and mortality; (c) life experiences and outcomes—including transitions such as retirement and menopause and events like trauma and crisis; (d) cognitive ageing and dementia risk; and (e) quality of life and social support networks.
Where possible, the review focuses on studies of diagnosed autistic people, but it also includes trait-based research because very high underdiagnosis in older cohorts limits the number of studies that specifically sample diagnosed older autistic adults. The review incorporates lifespan research where midlife and older groups are included but not always separated out due to limited sample sizes.
The article concludes by outlining priorities for future research and highlighting conceptual issues for investigators working at the intersection of autism and ageing, with the goal of informing policy and clinical practice to better support autistic people as they age.