Autism itself is not a terminal condition and does not directly cause death. It is a neurodevelopmental difference, not a disease that attacks organs or progresses over time. But autistic people do die significantly younger than the general population, and the reasons for that gap deserve a serious, honest look. In one 20-year study, autistic individuals who died did so at an average age of 39, roughly 38 years earlier than their expected lifespan.
Why Autistic People Die Younger
The life expectancy gap is real and substantial. Research tracking a Danish cohort over several decades found that autistic individuals died at twice the expected rate of the general population. A systematic review found that the highest standardized mortality ratio for autistic people was 5.6, meaning in certain groups, the risk of death was more than five times higher than average. These numbers don’t reflect autism acting as a disease. They reflect a cluster of related risks that compound over a lifetime.
The main drivers fall into a few categories: co-occurring medical conditions (especially epilepsy), accidental deaths from wandering, suicide, and a healthcare system that frequently fails autistic patients.
Epilepsy and Seizure-Related Death
About one-third of autistic people also have epilepsy, and this overlap carries real danger. Studies consistently show that autistic individuals with epilepsy have higher mortality rates than those with autism alone. Seizures can cause sudden unexpected death in epilepsy, a poorly understood event where a person with epilepsy dies during or shortly after a seizure with no other identifiable cause. For autistic people who have difficulty communicating changes in how they feel, seizure activity can go underreported and undertreated.
Drowning and Wandering Risks
Drowning is the leading cause of death for autistic children and is a significant risk for autistic adults as well. Autistic children are 160 times more likely to die from drowning compared to the general pediatric population. The pattern is strikingly consistent: a child wanders from home, reaches a nearby body of water, and drowns. In a review of fatal drowning incidents involving autistic children under 15, about 74% were preceded by wandering.
These drownings most commonly happen in ponds, not pools. Over half occurred in ponds, with lakes and rivers accounting for most of the rest. The average distance between the child’s home and the water was only about 300 meters. Most incidents happened in afternoon hours, between noon and 7 p.m., and the typical victim was a boy around 7 or 8 years old.
Many autistic children are strongly drawn to water, which makes proximity to any body of water a specific hazard. Families can reduce this risk in concrete ways. Adaptive swimming lessons taught by a certified instructor can make a significant difference, even if learning takes longer. GPS tracking devices, including wearable smartwatch trackers or waterproof holders for devices like AirTags that can be placed inside a shoe, help locate a child who has wandered. Securing exits at home and alerting neighbors are also practical steps.
Suicide Risk
This is one of the most important and least discussed parts of the life expectancy gap. Autistic children and teenagers attempt suicide at roughly double the rate of their non-autistic peers. For autistic adults, the numbers are far more alarming: available data suggests they are 25 times more likely to attempt suicide than non-autistic adults.
Depression co-occurs with autism at high rates, but it often goes unrecognized. Autistic people may express depression differently, or their distress may be attributed to autism itself rather than treated as a separate, treatable condition. Social isolation, sensory overload, difficulty accessing mental health care that accounts for autistic communication styles, and the cumulative stress of navigating a world not built for them all contribute. Research has described identifying depressive subgroups within the autistic population as a matter of “paramount importance.”
How the Healthcare System Contributes
A phenomenon called diagnostic overshadowing plays a quiet but deadly role. This happens when a healthcare provider sees a patient’s autism diagnosis and attributes physical symptoms to it, rather than investigating them as signs of a separate medical problem. A stomachache becomes “behavioral.” Fatigue becomes “part of the condition.” Pain goes uninvestigated.
The result is that physical illnesses in autistic people are underdiagnosed and undertreated. Reports describe physical health complaints being interpreted as symptoms of a mental health condition, leading to failures in both diagnosis and treatment. Provider bias, difficulty communicating symptoms in a traditional clinical setting, and time pressure during appointments all feed this cycle. In its most extreme form, diagnostic overshadowing leads to worsening conditions and preventable death.
Communication barriers make this worse. An autistic person who struggles to describe pain, locate symptoms, or advocate for further testing in a fast-paced medical appointment is at a structural disadvantage. This isn’t a failure of the individual. It’s a failure of a system that hasn’t adapted to serve them.
What Actually Shortens Autistic Lives
To put it plainly: autism does not kill people. But being autistic in a world with inadequate safety infrastructure, poorly adapted healthcare, and limited mental health support creates a web of risks that, taken together, shorten lives by decades. The average autistic person in one major study died nearly 39 years before their expected lifespan. That is not a biological inevitability of autism. It is a reflection of preventable causes: drowning, untreated epilepsy, suicide, and missed medical diagnoses.
Each of these risks has known interventions. Swimming lessons, GPS trackers, and secured homes reduce drowning deaths. Proactive epilepsy monitoring and treatment reduce seizure-related deaths. Mental health care designed for autistic people, not simply adapted from neurotypical models, can address the staggering suicide disparity. And training healthcare providers to look past an autism diagnosis when evaluating physical complaints could catch conditions that currently go unnoticed until they become dangerous.