A major new review indicates that elderly individuals are significantly less likely to receive an autism diagnosis.

The survey estimates that around 89% of individuals with autism aged between 40 and 59 have never been diagnosed. This figure rises to 97% for those over 60.

Our analysis compiled various studies on how autism impacts individuals later in life. The findings revealed that older autistic individuals face a high prevalence of both physical and mental health challenges, are less likely to have been adopted, and generally report poorer health.

Seniors on the autism spectrum encounter difficulties in accessing healthcare and building strong relationships, both of which are closely tied to health outcomes.

While autism is thought to affect roughly 1 in 100 people, the recorded diagnoses drastically drop for individuals over the age of 40.

This review highlighted U.S. data showing that autistic individuals experience higher rates of nearly all physical ailments compared to their non-autistic counterparts, including cardiovascular issues, immune disorders, and gastrointestinal problems. Furthermore, over half of older individuals with autism reported having at least one psychiatric issue, such as anxiety or depression.

“People with pronounced autistic traits, despite lacking a formal diagnosis, experience similar challenges,” stated Dr. Gavin Stewart, who led the King’s College London review.

“Being autistic yet undiagnosed can carry significant implications. Access to necessary support systems becomes limited for many undiagnosed autistic individuals, preventing them from addressing mental health concerns,” he explained to BBC Science Focus.

This lack of support complicates the ability of individuals with autism to navigate medical systems. Characteristics such as diverse communication styles, sensory sensitivities, and specific daily needs can make interactions with modern healthcare environments challenging.

For instance, autistic individuals may struggle to convey their symptoms to a non-autistic physician, particularly when overwhelmed by the sensory input of a noisy, brightly lit waiting area.

“Many autistic individuals express that it’s challenging to exist in a world that doesn’t accommodate their needs,” Stewart noted.

The challenge of forming relationships also contributes to greater social isolation among people with autism, leaving them without necessary support networks as they age.

“While many autistic individuals are socially motivated and cultivate fulfilling relationships, societal expectations can create obstacles that lead to their alienation,” Stewart added.

This study aims to highlight the lack of research on adults with autism, noting that a mere 0.4% of studies have focused on the condition in older populations.

“Rates of underdiagnosis are alarmingly high among older adults. Much of our research systematically overlooks a significant portion of the autistic population, resulting in a knowledge gap regarding how autistic individuals age and a deficiency in relevant policies and services,” Stewart commented.

“This oversight stems from the fact that many older autistic individuals today were likely missed due to the narrow diagnostic criteria used in their youth.”

Most autism diagnoses occur in childhood, yet the condition has only been recognized in diagnostic manuals since the 1960s.

“Since then, the criteria have shifted from a rare condition defined by narrow standards to a broader, more inclusive framework,” remarked Stewart.

Moreover, older autistic individuals are more prone to misdiagnosis; a 2019 study found that one-quarter of adults with autism were initially diagnosed with mental health disorders such as anxiety or personality issues before their autism was recognized.

Increasing awareness among educators, healthcare providers, and the general public has led to more individuals identifying autism symptoms in both children and adults.

About our experts

Dr. Gavin Stewart is a postdoctoral researcher at King’s College London, co-leading research with Professor Francesca Happé at the Respect Lab, focusing on autism across the lifespan.

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