A recent study revealed that most adults with autism in the United Kingdom over the age of 40 live without an official diagnosis, often leaving them without appropriate support and increasing their risk of health and social problems.

The study was conducted by researchers from the Institute of Psychiatry, Psychology and Neuroscience at King’s College London, UK, and its results were published in the Annual Review of Developmental Psychology on August 29, and covered by The Independent newspaper.

The researchers reanalyzed UK healthcare data from 2018 and estimated that among adults with autism aged 40 to 59, 91.45% of men and 79.48% of women had not received an official diagnosis.

The results also showed that the percentage of undiagnosed cases rises further in older age groups, reaching 96.29% in men and 97.19% in women over 60.

In contrast, the percentage was estimated at about 52.54% for those aged 20 to 39, and dropped to 23.34% for those under 19.

Experts indicate that these high rates cause many to live lives full of health and social challenges without proper understanding or support.

Tim Nichols, Deputy Director of Policy, Research and Strategy at the National Autistic Society UK, commented on these findings: “Medical assessment may be the first step to understanding their needs, and diagnosis can radically change some lives, and in some cases, it can be life-saving.”

To understand how autism may appear in later life stages, Dr. Lisa Williams, a clinical psychologist and founder of Autism Service Clinics UK, shared hidden signs of autism that may go unnoticed in adults over 40:

• Many older undiagnosed autistic adults tend to stick to a daily routine that gives them a sense of comfort and control.
• This becomes more apparent with age, as any sudden changes in routine become a source of stress and anxiety.
• This is seen, for example, in excessive pre-planning of appointments, strict adherence to daily habits, or feeling confused when unexpected changes occur.
• It is common for autistic individuals to have a deep passion for certain topics or hobbies, which is clear in older adults, but if this interest dominates most of their time and conversations repeatedly, it may be a sign of autism.
• Hypersensitivity may persist in autistic adults even in advanced age, including sensitivity to light, sounds, smells, and fabric textures.
• This may manifest as noticeable discomfort in crowded or noisy places, or when touching certain materials, reflecting differences in brain processing of sensory stimuli, a hallmark of autism.
• Change can be a major challenge for older undiagnosed autistic adults. Tasks like moving to a new home, starting a new job, or even using modern technology can cause anxiety due to unfamiliarity and instability of routine, and repeated difficulties can be a distinctive sign of autism.
• Older autistic adults may find it difficult to understand informal social behaviors such as eye contact, side conversations, respecting personal space, body language, or even light humor. Autistic people often think differently from others, may interpret things literally, or struggle to pick up social cues. They may feel out of sync in social situations and need more time to cope, even after years of experience.
• Despite their skillfulness in specific tasks, autistic individuals may struggle to adapt to frequent changes, workplace policies, or exhausting group meetings.
• Supportive managers providing accommodations such as clear instructions and task flexibility can help succeed, while lack of such support may lead to unnecessary stress, conflicts, or even unfair penalties.

It is noteworthy that the signs mentioned by experts are not diagnostic tools by themselves but indicators that may appear in some autistic individuals and can overlap with other conditions or personality traits such as anxiety, depression, or sensory sensitivity. Accurate autism diagnosis requires comprehensive evaluation by qualified specialists, as autism is a broad spectrum with widely varying manifestations among individuals.