Forgotten Generation: Why Have So Many Autistic Adults Never Been Diagnosed?

Autism is a lifelong, distinct form of brain functioning. Although it is increasingly recognized in children, many adults, especially those over 40, have never been diagnosed. This has serious consequences: autistic people face more physical and mental health problems, a higher risk of social isolation, and a lower life expectancy. Research shows that adequate support and support networks make a big difference, but studies and policies geared toward autistic adults and older adults are still lacking.

Autism is a condition that is part of brain development and accompanies a person throughout life. It is not a disease, but rather a distinct form of neurological functioning. Autistic people often exhibit differences in the way they communicate, interact socially, and process information.

Furthermore, they often have specific interests and repetitive behaviors. These characteristics vary greatly from person to person, which is why today we speak of the "autism spectrum" to demonstrate that there are many ways to experience and express autism.

Research shows that autistic people, in addition to communication and behavioral differences, may experience more physical and mental health problems, such as depression, anxiety, cardiovascular disease, and gastrointestinal disorders. Many also report experiencing greater difficulties in areas such as relationships, work, and quality of life compared to non-autistic people.

Currently, it is estimated that approximately 1 in 100 people worldwide are autistic. However, diagnosis still does not reach everyone fairly. While autism is now more frequently identified in children and adolescents, especially in the younger generations, there are a large number of adults, especially middle-aged and older adults, who have never received a diagnosis.

Studies show that, among people over 40, between 89% and 97% may be autistic without knowing it. This means they have spent their entire lives without recognition, adequate support, or necessary adaptations.

This delay occurs because diagnostic criteria have changed significantly over time. Until the 1960s, autism was seen as rare, often confused with schizophrenia, and generally identified only in boys with intellectual disabilities or speech delays.

Indexed research articles on autism published since 1980, stratified by age group studied. The bar graph illustrates the total number of articles, and the line graph illustrates the number of articles published per year.

As research progressed, understanding expanded, and in 2013, it began to be described as a more diverse spectrum, also including girls, women, and people with varying levels of abilities. Thus, many people who went unrecognized in childhood are now receiving a diagnosis as adults or older adults.

Despite this progress, we still know little about what it's like to grow old with autism. What is already clear is that autistic people face higher risks for virtually every physical and mental health condition compared to the general population. This includes age-related diseases such as Parkinson's, osteoporosis, arthritis, and even a higher risk of early-onset dementia.

It has also been observed that older autistic people have higher rates of social isolation and, unfortunately, a much higher risk of suicidal thoughts and self-harm.

Another worrying fact is that the average life expectancy of autistic people is about six years shorter than that of the general population. While the average for non-autistic people is around 81 years, for autistic people it is around 75 years.

It's important to remember that these numbers may be distorted by the large number of people who have not yet been diagnosed, but they point to serious inequalities in health and quality of life.

Estimates of the percentage of diagnosed and undiagnosed autistic individuals in the United Kingdom, stratified by age group (i.e., youth, young adults, middle-aged adults, and older adults). The data suggest a global autism prevalence of 1% and a male-to-female ratio of 2:1.

Health systems in many countries are not prepared to meet the specific needs of this population. Communication differences, sensory sensitivities (such as sounds and lights), and a lack of knowledge about autism in adulthood among professionals create obstacles to these individuals receiving the care they need.

Still, recent research shows the importance of social support. Autistic individuals who have a support network of family, friends, and inclusive communities tend to have a better quality of life and greater emotional well-being. This indicates that, in addition to medical care, social and relationship factors are fundamental to the health of this population.

In short, aging with autism is a topic that is beginning to gain more scientific attention, but remains largely unexplored. What we already know is that autistic adults, especially older adults, face serious inequalities in health, well-being, and access to services.

This makes it urgent that society, health professionals, and public policymakers invest in research and practical measures to ensure that these individuals receive the care, recognition, and support they deserve throughout their lives.

READ MORE:

Aging Across the Autism Spectrum

Gavin R. Stewart and Francesca Happé

Annual Review of Developmental Psychology, Vol. 7 

https://doi.org/10.1146/annurev-devpsych-111323-090813

Abstract: 

Aging in autistic populations is a historically neglected but now rapidly advancing area of research. This narrative review provides a broad overview of the current state of the field of aging on the autism spectrum by synthesizing and critically appraising findings from across a range of research priorities identified by autistic people and other stakeholder groups. These include (a) the trajectory of core autistic features; (b) health profiles, biological aging, and mortality; (c) influential life experiences and life outcomes (including transition periods such as retirement and menopause and events such as trauma and periods of crisis); (d) cognitive function, aging, and dementia; and (e) quality of life and social support. Where possible, empirical research focusing on diagnosed autistic people is presented, but due to very high rates of underdiagnosis of autism in this demographic, trait-based research is also considered. Research specifically focusing on midlife (i.e., 40–64 years) and older age (i.e., 65 years and older) is presented where available, but due to a dearth of such research, lifespan studies (i.e., samples including middle-aged and older people, but not differentiating them) are also discussed. This review concludes by identifying future research priorities, as well as key conceptual issues that researchers interested in the intersection of aging and autism should consider for this emerging and rapidly advancing area of research.