Recent research published in natural mental health This suggests that middle-aged and older adults with high levels of autistic traits tend to be at increased risk for worsening anxiety as they age. The findings provide evidence that this population may face distinct mental health challenges over time. This points to the need for customized support systems for older adults on the autism spectrum.
Autism spectrum disorder is a lifelong neurodevelopmental condition that involves differences in social communication and rigid or repetitive behaviors. Although not included in formal diagnostic criteria, mental health conditions such as anxiety often co-occur with autism. Up to 42 percent of people with autism will experience anxiety disorders during their lifetime. Autistic people have always recognized anxiety as a top priority for scientific research because of its profound impact on daily functioning and overall well-being.
A joint team of scientists from University College London, King’s College London, the University of Exeter, the University of Liverpool and the Bradford Health Research Institute conducted this study to address this gap in the literature. The project was co-supervised by Amber John and Gavin Stewart, Senior Research Fellow at King’s College London and co-leader of the Respect Lab. Joshua Stott, professor of aging and clinical psychology and director of the ADAPT Lab at University College London, served as corresponding author with Stewart.
“Anxiety is one of the most common mental health issues experienced by people with autism,” Stewart and Stott said in a joint email. “This is also one of the top research topics raised by people with autism.”
“Yet, few studies have investigated how anxiety changes with age in the context of autism,” the researchers added. “We wanted to investigate whether autistic traits (as a surrogate for an autism diagnosis, as many middle-aged and elderly people are likely to be undiagnosed) are associated with different patterns of anxiety as we age.”
Most existing research on autism and anxiety focuses on children and young adults. Our understanding of how anxiety affects people with autism from middle age onwards remains quite limited. Previous studies examining changes in mental health in older adults with autism have mostly observed participants at one point in time, rather than following them over years. These snapshot studies have yielded mixed results, with some suggesting lower rates of clinical anxiety in older autistic populations and others finding quite the opposite pattern.
A major hurdle in studying older adults with autism is the high rate of underdiagnosis. Estimates suggest that 9 out of 10 adults with autism who are middle-aged or older do not have a formal diagnosis. This gap is likely due to how diagnostic criteria and medical understanding of autism have changed over the past 50 years. The older adults who now need help grew up in a time when autism was rarely recognized unless they had severe intellectual or language impairments.
To circumvent this diagnostic gap, scientists used a trait-based approach rather than requiring a formal medical diagnosis. Trait-based approaches involve identifying people who report high levels of autistic traits, even if they have not been formally evaluated by a doctor. This method allows researchers to collect a broader and more representative sample of older adults who may be on the autism spectrum. By following these people over time, the authors hoped to see whether endorsing high levels of autistic traits was associated with specific age-related patterns of anxiety.
To explore these questions, scientists analyzed data from the PROTECT study. This is an ongoing online project in the UK focused on aging and brain health. The analysis included 5,270 adults aged 50 to 91 years, with a median age of 62 years. The sample was predominantly female, representing 75 percent of the participants. Participants took part in the study and completed annual follow-up assessments over eight years, providing a long-term view of their mental health.
At the beginning of the study, participants completed a special questionnaire designed to measure autistic traits. This five-item screening tool asked participants whether they currently struggle with social interactions, such as understanding other people’s perspectives or recognizing sarcasm. They were also asked if they had experienced similar social and communication difficulties in childhood. This dual focus ensures that the traits persist throughout life and are consistent with the developmental nature of autism.
Based on their answers, researchers divided participants into different categories. A total of 66 participants, representing approximately 1.3 percent of the sample, endorsed high levels of both childhood and current autistic traits. Another 3,874 participants, representing 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, researchers used a standard seven-item questionnaire known as the Generalized Anxiety Disorder Assessment. This tool asks individuals to rate how often they have suffered from anxiety symptoms, such as excessive worrying or restlessness, over the past two weeks. Participants completed this anxiety measure at the initial assessment and during annual follow-up for up to 8 years. The scientists also measured symptoms of depression at the beginning of the study to account for potential effects on anxiety levels.
The authors analyzed the data using an advanced statistical technique called growth mixture modeling. This method helps scientists identify unobserved subgroups within large populations by grouping individuals who share similar developmental patterns over time. In addition to looking at average anxiety scores across groups, this approach allowed the researchers to identify distinct pathways of anxiety symptoms over an eight-year follow-up period.
Statistical analysis revealed three specific anxiety pathways within the sample. The largest group, which the researchers called the “low-range minimal anxiety class,” included 85.6 percent of participants who maintained very low anxiety scores throughout the eight-year period. The second group, containing 12.4 percent of the sample, was placed in the upper, least anxious class. People in this second group had slightly higher anxiety scores than the first group, but their symptoms were still below the threshold for clinical concern.
The third group was the smallest, accounting for only 2% of the total sample. Researchers described this group as following a mild to clinical anxiety pathway. People in this class begin with mild anxiety symptoms that steadily worsen over an eight-year period, eventually reaching clinical levels that usually require treatment.
“Most middle-aged and older adults maintain low levels of anxiety over time,” Stewart and Stott explained. “However, a small group experience worsening of their anxiety over time, and people with more advanced autistic traits are much more likely to be in this group.”
Statistical models showed that participants with high autistic traits were more than four times more likely to be in the upper end of minimal anxiety compared to participants without autistic traits. More notably, those high on the trait 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 participants’ age, gender, and baseline depression levels.
“People with high-grade autistic traits were more than four times more likely to have persistent anxiety symptoms of clinical concern, even when other factors were taken into account,” the researchers noted.
The findings provide evidence that the increased risk of anxiety associated with autism persists well into middle age and beyond. In the third group, a gradual increase from mild anxiety to clinical anxiety suggests that some older adults with autistic traits experience a severe mental health burden. The authors note that people with autism often face adverse experiences throughout their lives, including social isolation, loneliness, and repeated barriers to accessing health care. These lifelong challenges may contribute to worsening anxiety over the years.
“These findings highlight the importance of recognizing anxiety early and ensuring people receive appropriate support before symptoms worsen,” Stewart and Stott said.
Although this study provides useful insights, there are some limitations that should be considered. Because the data relies on simple screening tools, researchers are unable to confirm whether individuals in the high-trait group meet formal medical criteria for an autism diagnosis.
“Because this study is observational, we cannot determine why anxiety increases for some people,” the researchers noted. “We also measured autistic traits, rather than relying solely on a formal autism diagnosis. However, 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 pathway, means that statistical results should be interpreted with some caution, as small samples may reduce statistical precision. The demographic composition of the sample is also limited. Participants were primarily white, female, and highly educated and did not fully reflect the diversity of the general population. Of note, there were no individuals from ethnic minority backgrounds in the high autistic traits group. This lack of diversity means that the findings may not accurately represent the experiences of older adults with autism from different cultural or racial backgrounds, who may face common challenges.
Future research should aim to replicate these findings in larger and more diverse samples, including adults formally diagnosed with autism. Scientists could also investigate whether this worsening of anxiety pathways is unique to people with autistic traits or also occurs in other neurodivergent populations.
“Future research will aim to better understand why some people with autistic traits are more likely to experience increased anxiety later in life, and to identify effective interventions,” Stewart and Stott explained. “We are particularly interested in developing and evaluating tailored supports and psychotherapies that can help prevent mild anxiety from becoming severe.”
“This study highlights the need for autism-aware health services for older adults,” the researchers concluded. “Many middle-aged and older autistic people may not have a formal diagnosis but still need appropriate mental health support. Working closely with autistic people to understand their lived experiences is essential to improving care and outcomes as they age.”
The study, “Association between autistic traits and anxiety trajectories in middle-aged and older adults: An 8-year developmental mixed model analysis,” was authored by Aphrodite Eshetu, Saloni Guy, Ann Corbett, Clive Ballard, Adam Hampshire, Elizabeth Onions, William Mundy, Joshua Stott, Amber John, and Gavin R. Stewart.
