New research published in natural mental health Higher rates of suicidal ideation and self-harm among older adults with autistic traits suggest that the traits themselves are not directly responsible. Rather, this increased risk appears to be driven by accompanying challenges such as depression, trauma, and social isolation. These findings provide evidence that targeted mental health support and promoting social connections may help protect this vulnerable population.
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Much of autism research focuses on children and adolescents. Focusing on this issue, there is a lack of information about how this condition affects people in middle age and beyond.
Older adults with autism have been found to have worse outcomes in terms of reduced life expectancy. They also have a disproportionately higher risk of developing mental health problems such as anxiety and depression compared to non-autistic adults. Epidemiological data suggests that up to 90 per cent of autistic adults aged over 50 in the UK remain undiagnosed or misdiagnosed.
At the same time, previous research has shown that people diagnosed with autism are at a much higher risk of dying by suicide than the general population. Understanding the factors that influence suicide risk in older adults is a top priority in public health. Older adults are generally at increased risk for suicide overall, and the unique social and mental health challenges experienced by people with autistic traits can further exacerbate this risk.
“Suicide has been identified as the leading cause of death in the autistic population, and the risk of suicide in the general population increases rapidly in older age,” study author Gavin Stewart and Josh Stott, Senior Research Fellow at King’s College London and Professor of Aging and Clinical Psychology at University College London, explained respectively.
“Our previous research has shown that middle-aged and older autistic people have significantly higher rates of suicidal ideation (thoughts of death or dying) and suicidal self-harm. Yet, the causes of this suicidal behavior in older autistic people are understudied.”
For the new study, researchers analyzed data from an ongoing online health study in the UK known as the PROTECT study. The sample included 9,979 adults aged 50 to 97 years. Approximately 75% of participants were women.
Because autism is so often undiagnosed in older generations, the scientists used a 10-question survey to measure autism traits, rather than relying on official medical diagnoses. Participants who scored high in this study were placed into a high autistic traits group of 672 people. The remaining 9,307 participants formed the low autistic traits group.
Participants completed several questionnaires designed to measure current mental health and social well-being. These studies examined symptoms of depression, anxiety, and post-traumatic stress disorder. The term post-traumatic stress disorder refers to a mental health condition caused by experiencing or witnessing a frightening event.
The survey also measured two different social concepts: loneliness and social isolation. Loneliness is defined as a person’s subjective negative feeling of being alone. Social isolation is defined as an objective lack of regular contact with friends and family. Finally, the researchers asked participants if they had ever experienced the idea that life was not worth living or if they had ever harmed themselves in an attempt to end their life.
The researchers used a statistical technique called path analysis to examine indirect relationships between variables. This method helps scientists understand whether intermediate factors, known as mediators, explain the relationship between a starting point and an ending point.
Scientists found that adults in groups high in autistic traits had higher rates of suicidal ideation. Specifically, 29 percent of the high-trait group experienced suicidal ideation multiple times, compared to just 16 percent of the low-trait group. Self-harm with suicidal intent was also twice as common in the high-trait group, affecting 6 percent of those participants compared to 3 percent of other participants.
When the researchers looked deeper using statistical models, they found that the direct link between autistic traits and suicidal behavior was actually very weak. Rather, high rates of suicidal ideation were almost entirely mediated by symptoms of depression, anxiety, post-traumatic stress disorder, loneliness, and social isolation. This provides evidence that these associated mental and social conflicts, rather than autistic traits themselves, explain the higher risk.
The path of suicidal self-harm was slightly different. Researchers found that suicidal self-harm behavior was mediated by depression, post-traumatic stress disorder, social isolation, and being male. Anxiety symptoms and subjective loneliness did not mediate the relationship between autistic traits and suicidal and self-injurious behavior.
“Overall, our findings suggest that improving mental health support and social connections for adults with autism, especially those over 50, may help reduce the risk of suicidal behavior,” Stewart and Stott told SciPost.
Although the effects of individual mental health and social problems on their own are relatively small, the researchers noted that these factors often co-occur. In their analysis, as the severity of one mental health problem increased, other problems tended to become more severe as well. This cumulative burden tends to have a significant impact, ultimately pushing the individual into a state of crisis.
“The main conclusion of our study is that the higher incidence of suicidal ideation and suicidal self-harm behaviors in adults with advanced autistic traits is not directly related to autism itself,” Stewart and Stott explained. “Rather, they are primarily associated with other challenges that adults with autism may experience, particularly mental health difficulties and social isolation.”
“Issues such as depression, anxiety, traumatic experiences, loneliness, and social isolation explain the increased risk of suicidal behavior. Each of these issues may have a small effect on its own, but together they can have a meaningful impact on someone, leading to a crisis situation like suicide.”
Researchers warn of potential misinterpretations of research regarding formal autism diagnoses. Because the study focused on people with high-level autistic traits rather than formally diagnosed autism, it is impossible to be certain whether all participants in the high-trait group met the strict clinical criteria for autism.
“Our study focuses on people with advanced autistic features, rather than the diagnosis of autism,” Stewart and Stott said. “We used this approach because we know that the underdiagnosis of autism is very high in adult populations, particularly in midlife and old age. We want to note that while using measures of autistic traits is a powerful way to explore the experiences of populations that are often underdiagnosed, it is not a substitute for exploring the experiences of populations diagnosed with autism.”
Another limitation of this study is its cross-sectional design, meaning that data were collected at a single time point. Because of this, scientists are unable to prove a strict cause-and-effect relationship between mental health problems and suicidal behavior.
Future research could follow individuals over time to determine how mental health symptoms and suicidal thoughts develop over time. Researchers plan to continue investigating the experiences of middle-aged and older people on the autism spectrum.
“Our research groups (KCL’s ReSpect Lab and UCL’s ADAPT Lab) have a range of ongoing studies investigating the experiences of middle-aged and older people with autism,” the researchers explained. “Together, we have a particular interest in improving the identification of undiagnosed autistic people and, more broadly, improving access to mental health support for autistic people. We are also interested in ways to improve the identification and care of age-related conditions and people living with dementia.”
The study, “Autistic traits and suicidality in midlife and old age: investigating the mediating effects of mental health and social connectedness,” was authored by Eleanor Nazum, Radvir Medecité, Aphrodite Eshetu, Sarah Hoare, Ann Corbett, Clive Ballard, Adam Hampshire, Elizabeth Onions, Amber John, Gavin R. Stewart, and Joshua Stott.
