Autism Spectrum Disorder (ASD) is a complex neurodevelopmental condition characterized by differences in social communication, along with restricted or repetitive patterns of behavior. Individuals with ASD face a significant disparity in life expectancy compared to the general population. Studies consistently show that mortality rates across the lifespan are elevated, often estimated to be twice as high as those of neurotypical peers. The average age of death for individuals with ASD is often decades lower than the general population. This gap underscores the urgency of identifying and mitigating the primary factors contributing to premature death.
The Primary Mortality Risk: Unintentional Injuries
The single leading cause of premature death in individuals with autism, particularly children and young adults, is unintentional injury. Individuals on the spectrum are three times more likely to die from injury than the general population. For children with ASD, the most devastating cause of injury-related mortality is accidental drowning, with the risk found to be 160 times higher than for the typical pediatric population. This heightened risk is often due to elopement, or wandering, where an individual leaves a safe environment unnoticed. Nearly half of children with autism attempt to elope, and when elopement is fatal, drowning accounts for the majority of deaths, often exceeding 70%.
Many autistic individuals are drawn to water, possibly due to sensory seeking or a lack of understanding of danger. Traffic accidents are the second most common cause of fatal injury following elopement, especially among older children and adolescents. Impaired danger awareness, difficulty with complex communication, and intense focus on a specific sensory target can lead to tragic encounters with vehicles. Other causes of injury death include suffocation and asphyxiation, which are also highly elevated in this population. The average age of death for all injury-related fatalities in the ASD population is often reported around 36 years.
Co-occurring Physical Health Conditions
Co-occurring medical conditions contribute significantly to the reduced life expectancy in the ASD population. Epilepsy is one of the most serious neurological comorbidities, with prevalence estimates reaching up to 20-30% in individuals with ASD, particularly those who also have an intellectual disability. The co-occurrence of epilepsy and autism is a major risk factor, increasing mortality rates by over 800% in some studies. A specific risk is Sudden Unexpected Death in Epilepsy (SUDEP), which accounts for some sudden, unexplained deaths in this community. Underlying neurological differences in ASD often make individuals more susceptible to seizure disorders, which elevates the risk of SUDEP.
Individuals with ASD also face an increased risk for cardiovascular disease, being two to three times more likely to develop heart conditions than neurotypical adults. This elevated risk is compounded by factors like chronic stress, poor sleep quality, and the metabolic side effects of some psychotropic medications. Gastrointestinal (GI) disorders are four times more common in the ASD population, with chronic issues like severe constipation and abdominal pain being frequent complaints. These chronic physical conditions are often under-treated or misdiagnosed. Attributing physical symptoms to behavioral issues can delay the identification of life-threatening complications or severe underlying medical problems, indirectly contributing to mortality.
Mental Health, Suicide Risk, and Diagnostic Challenges
Mental health conditions are a significant contributor to the mortality gap, with suicide being a major cause of death, especially in adults. Individuals with ASD have an elevated risk of suicidal ideation and attempts, often several times higher than the general population. Co-occurring mental illnesses, such as anxiety and depression, are highly prevalent and fuel this risk. A major barrier to appropriate care is diagnostic overshadowing, where symptoms of a co-occurring illness are mistakenly attributed to the existing autism diagnosis. For instance, a clinician might dismiss reports of depression or anxiety as merely a core feature of autism, delaying necessary psychiatric intervention.
This issue is prevalent in individuals who “mask” or camouflage their autistic traits, often leading to a later ASD diagnosis preceded by years of untreated mental health crises. The psychological distress is often exacerbated by a lifetime of social isolation, bullying, and the constant struggle to navigate a neurotypical world. When a mental health crisis occurs, the underlying condition is frequently overlooked, leading to inadequate support and inadequate treatment. This systemic failure to accurately diagnose and treat co-occurring psychiatric conditions is a direct factor in the disproportionately high suicide rate in the autistic community.
Reducing Mortality Risk and Improving Lifespan
Closing the mortality gap requires a multi-pronged approach focusing on safety interventions and improved healthcare. Since drowning is the leading cause of accidental death, specialized water safety training and swimming lessons are necessary for children diagnosed with ASD. Environmental modifications are crucial to prevent elopement from the home. These include installing specialized safety alarms, secure locks, and fencing on doors and windows. Technology also plays a practical role, with personal safety devices like GPS trackers providing a rapid means of locating a person who has wandered.
Aggressive screening protocols are necessary for co-occurring medical conditions. Healthcare providers must vigilantly monitor for signs of epilepsy and cardiovascular issues, particularly in adults, avoiding the trap of diagnostic overshadowing to ensure timely and appropriate treatment. Specialized training for first responders and law enforcement is also a practical intervention to reduce harm during crisis situations. Training focuses on recognizing unique behavioral characteristics, using simple, clear language, and employing de-escalation techniques. By increasing awareness and providing specific crisis intervention strategies, communities can significantly improve the outcome of emergency encounters.