A recent study published in Nature Mental Health suggests that middle-aged and older adults with elevated autistic traits tend to experience an increased risk of worsening anxiety as they age. The findings provide evidence that this population may face distinct mental health challenges over time. This points to a need for tailored support systems for older adults on the autism spectrum.
Autism spectrum disorder is a lifelong neurodevelopmental condition involving differences in social communication and rigid or repetitive behaviors. While not part of the formal diagnostic criteria, mental health conditions like anxiety frequently co-occur with autism. Up to 42 percent of autistic individuals experience an anxiety disorder during their lifetime. Autistic people consistently identify anxiety as a top priority for scientific inquiry, as it significantly impacts their daily functioning and overall well-being.
A collaborative team of scientists from University College London, King’s College London, the University of Exeter, the University of Liverpool, and the Bradford Institute for Health Research conducted the study to address this gap in the literature. The project was jointly supervised by Amber John and Gavin Stewart, a senior research fellow at King’s College London and co-lead of the ReSpect Lab. Joshua Stott, a professor of aging and clinical psychology at University College London and director of the ADAPT Lab, served as a corresponding author alongside Stewart.
“Anxiety is one of the most common mental health problems experienced by autistic people,” Stewart and Stott said in a joint email. “It’s also one of the top priority research topics raised by autistic people.”
“Despite this, very little research has examined how anxiety changes as people age in relation to autism,” the researchers added. “We wanted to explore whether autistic traits (as a proxy for autism diagnosis, as many middle-aged and older people are likely to be undiagnosed) are linked to different patterns of anxiety as people age.”
Most existing research on autism and anxiety focuses on children and younger adults. Our understanding of how anxiety affects autistic people during midlife and older age remains quite limited. Past studies looking at mental health changes in older autistic adults have mostly observed participants at a single point in time rather than tracking them across years. These snapshot studies yield mixed results, with some suggesting lower rates of clinical anxiety in older autistic populations and others finding the exact opposite pattern.
A major hurdle in studying older autistic adults is the high rate of underdiagnosis. Estimates indicate that nine out of ten autistic adults in midlife or older age do not have a formal diagnosis. This gap likely stems from how diagnostic criteria and the medical understanding of autism have shifted over the past fifty years. Older individuals who need support today were raised in an era when autism was rarely recognized unless it presented with severe intellectual or language disabilities.
To bypass this diagnostic gap, the scientists used a trait-based approach rather than requiring a formal medical diagnosis. A trait-based approach involves identifying people who report high levels of autistic characteristics, even if they have never been formally assessed by a doctor. This method allows researchers to capture a broader and more representative sample of older adults who might be on the autism spectrum. By tracking these individuals over time, the authors wanted to see if endorsing high levels of autistic traits is associated with specific patterns of anxiety as people age.
To explore these questions, the scientists analyzed data from the PROTECT study. This is an ongoing online project in the United Kingdom focused on aging and brain health. The analysis included 5,270 adults between the ages of 50 and 91, with a median age of 62. The sample was predominantly female, making up 75 percent of the participants. Participants entered the study and completed annual follow-up assessments over an eight-year period, providing a long-term view of their mental health.
At the beginning of the study, participants completed a specialized questionnaire designed to measure autistic traits. This five-item screening tool asked participants if they currently struggle with social interactions, such as understanding other people’s perspectives or recognizing sarcasm. It also asked if they experienced similar social and communication difficulties during childhood. This dual focus ensures that the traits are lifelong, which aligns with the developmental nature of autism.
Based on their responses, the researchers divided the participants into different categories. A total of 66 participants, representing about 1.3 percent of the sample, endorsed high levels of both childhood and current autistic traits. Another 3,874 participants, making up 73.5 percent of the group, reported no autistic traits at all. The remaining participants either had missing data or reported some traits but did not meet the strict threshold for the high-trait group.
To track anxiety over time, the researchers used a standard seven-item questionnaire known as the Generalized Anxiety Disorder assessment. This tool asks individuals to rate how often they have been bothered by anxiety symptoms, such as excessive worrying or feeling restless, over the past two weeks. Participants completed this anxiety measure at their initial assessment and during each annual follow-up for up to eight years. The scientists also measured depression symptoms at the start of the study to account for its potential influence on anxiety levels.
The authors used an advanced statistical technique called growth mixture modeling to analyze the data. This method helps scientists identify unobserved subgroups within a large population by grouping individuals who share similar developmental patterns over time. Instead of just looking at the average anxiety score for the whole group, this technique allowed the researchers to spot distinct paths of anxiety symptoms across the eight-year tracking period.
The statistical analysis revealed three specific anxiety paths within the sample. The largest group, which the researchers called the lower-range minimal anxiety class, contained 85.6 percent of the participants who maintained very low anxiety scores throughout the entire eight years. The second group, containing 12.4 percent of the sample, was labeled the upper-range minimal anxiety class. People in this second group had slightly higher anxiety scores than the first group, but their symptoms still remained below the threshold for clinical concern.
The third group was the smallest, comprising just 2 percent of the total sample. The researchers described this group as having a mild-to-clinical anxiety path. Individuals in this class started with mild anxiety symptoms that steadily worsened over the eight years, eventually reaching clinical levels that would typically warrant medical treatment.
“Most middle-aged and older adults maintain low levels of anxiety over time,” Stewart and Stott explained. “However, a small group experienced worsening anxiety over time, and people with higher autistic traits are much more likely to be in this group.”
The statistical models showed that participants with elevated autistic traits were over four times more likely to belong to the upper-range minimal anxiety group compared to those with no autistic traits. Even more notably, the high-trait individuals were about 14 to 15 times more likely to fall into the mild-to-clinical anxiety group. This association remained strong even after the researchers adjusted the data to account for the participants’ age, sex, and baseline depression levels.
“People with higher autistic traits were more than four times as likely to have persistent anxiety symptoms in a range that is of clinical concern, even after accounting for other factors,” the researchers noted.
The findings provide evidence that the heightened risk of anxiety associated with autism continues well into midlife and older age. The gradual increase from mild to clinical anxiety in the third group suggests that some older adults with autistic traits experience a compounding mental health burden. The authors note that autistic individuals often face a lifetime of adverse experiences, such as social isolation, loneliness, and repeated barriers to healthcare access. These lifelong challenges likely contribute to this worsening anxiety over the years.
“The findings highlight the importance of recognizing anxiety early and ensuring people receive appropriate support before symptoms become more severe,” Stewart and Stott said.
While the study offers informative insights, it does have some limitations to consider. Because the data relies on a brief screening tool, the researchers cannot confirm if the individuals in the high-trait group would meet the formal medical criteria for an autism diagnosis.
“The study was observational, so it cannot determine why anxiety increases for some people,” the researchers pointed out. “We also measured autistic traits rather than relying solely on formal autism diagnoses, although this was important because many middle-aged and older autistic adults remain undiagnosed.”
The small size of the high-trait group, especially within the worsening anxiety path, means the statistical results should be interpreted with some caution, as smaller samples can sometimes reduce statistical precision. The demographic makeup of the sample also presents a limitation. The participants were predominantly white, female, and well-educated, which does not reflect the full diversity of the general population. Notably, there were no individuals from minority ethnic backgrounds in the high autistic trait group. This lack of diversity means the findings might not accurately represent the experiences of older autistic adults from different cultural or racial backgrounds, who may face unique intersectional challenges.
Future research should aim to replicate these findings in larger, more diverse samples that include formally diagnosed autistic adults. Scientists could also explore whether these worsening anxiety paths are unique to people with autistic traits or if they occur in other neurodivergent populations.
“Future research will aim to better understand why some people with autistic traits are more vulnerable to increasing anxiety in later life and to identify effective interventions,” Stewart and Stott explained. “We are particularly interested in developing and evaluating tailored support and psychological therapies that could help prevent mild anxiety from becoming severe.”
“The study highlights the need for autism-aware healthcare services for older adults,” they concluded. “Many middle-aged and older autistic people may not have a formal diagnosis but still require appropriate mental health support. Working closely with autistic people to understand their lived experiences will be essential for improving care and outcomes as they age.”
The study, “The association between autistic traits and trajectories of anxiety in middle-aged and older adults: an 8-year growth mixture model analysis,” was authored by Aphrodite Eshetu, Saloni Ghai, Anne Corbett, Clive Ballard, Adam Hampshire, Elizabeth O’Nions, William Mandy, Joshua Stott, Amber John, and Gavin R. Stewart.
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