A sweeping new review from King’s College London reveals a startling reality: in the UK, nearly 89% of autistic individuals aged 40–59 and 97% of those over 60 remain undiagnosed or were misdiagnosed earlier in life. 

These figures expose a hidden crisis — one where decades elapsed without recognition or support, often with devastating consequences. Older autistic adults face disproportionately high rates of mental and physical health challenges, including anxiety, depression, cardiovascular conditions, neurological disorders, early-onset dementia, and suicidal thoughts. Alarmingly, their life expectancy is an average six years shorter than that of non-autistic peers. 

As major life transitions like retirement or residential care arise, lack of a diagnosis can intensify isolation and distress. Researchers emphasize that recognition — even later in life — can be profoundly transformative, enabling access to tailored healthcare, social support, and self-understanding. 

The review calls for urgent investment in diagnostic services and community-informed support systems that embrace a lifespan-informed approach to autism.