Autism, Mental Health and Suicide: What the Research Shows
Article one of three. Minds in Session.
This article discusses suicide and suicidal thinking in general terms. It contains no description of methods and no individual accounts. If you are struggling as you read, the sources of help listed at the end are there for you.
Suicide risk among autistic people has been the subject of sustained empirical attention for a little over a decade. The findings are consistent across countries, research groups and study designs, and they remain largely unknown outside the field. This article sets out what has been established, what remains uncertain, and what the evidence indicates about why the risk is raised.
Where the evidence begins
The modern literature dates from 2014, when Sarah Cassidy, Simon Baron-Cohen and colleagues published a clinical cohort study in The Lancet Psychiatry. Baron-Cohen is Professor of Developmental Psychopathology at the University of Cambridge and Director of its Autism Research Centre and is among the most influential researchers in autism internationally; Cassidy, now Associate Professor of Psychology at the University of Nottingham, has led much of the work in the United Kingdom that followed.
They surveyed 374 adults newly diagnosed with Asperger's syndrome at a specialist adult diagnostic clinic. Sixty-six percent reported lifetime suicidal ideation, compared with approximately 17% in the general United Kingdom population and 59% among patients with a psychotic illness. Thirty-five percent reported suicide plans or attempts. Co-occurring depression raised the odds of ideation more than fourfold, and those reporting plans or attempts had higher autistic trait scores.
The authors were explicit that a clinic sample over-represents people already in difficulty and that the finding required replication in wider populations. The decade since has supplied it.
Prevalence in community samples
The most rigorous synthesis available is a systematic review and meta-analysis published in Molecular Autism in 2023 led from the University of Nottingham by Victoria Newell, with Cassidy as senior author. It pooled 36 studies covering 48,186 autistic and possibly autistic people without a co-occurring intellectual disability.
Lifetime suicidal ideation was estimated at 34.2%, suicide plans at 21.9%, and suicide attempts or related behaviours at 24.3%. The authors' comparison figures for the general population are approximately 9%for ideation and 2 to 3%for plans and attempts.
Two limitations should be stated. Heterogeneity across the included studies was high, which means the pooled percentages carry wide uncertainty and are best read as an order of magnitude rather than a precise value. Secondly, recruitment across this literature under-represents autistic people with intellectual disability, those who do not use speech, and those who have never been assessed; so the estimates describe a particular and comparatively able segment of the autistic population.
Mortality
The mortality evidence comes principally from Swedish national registers. Tatja Hirvikoski and colleagues at the Karolinska Institutet, publishing in the British Journal of Psychiatry in 2016, followed 27,122 people with a diagnosis of autism spectrum disorder against 2,672,185 matched population controls.
The odds of death by suicide were raised approximately sevenfold across the autistic cohort as a whole. The distribution within that cohort is the more instructive finding. Amongst those with a co-occurring intellectual disability the odds ratio was 2.41; among those without, it was 9.40. Mean age at death was 53.9 years across the autistic cohort against 70.2 years in controls.
This runs against the intuition that greater apparent capability implies lower clinical risk. Suicide was the only specific cause of death in this study for which the risk was higher among autistic people without an intellectual disability than among those with one.
The elevated mortality risk itself has been confirmed in other national datasets. Danish register data covering more than six million people, published by Kairi Kõlves and colleagues in JAMA Network Open in 2021, found the rate of death by suicide among 35,020 autistic people to be close to four times that of the general population, and the rate of suicide attempts among autistic women to be more than four times that among autistic men. The concentration of risk amongst those without a co-occurring intellectual disability, however, rests principally on the Swedish data and awaits fuller replication.
What these figures do and do not establish
A raised population-level risk supports no inference about any individual. Most autistic people are not suicidal, and most autistic people who experience suicidal thinking do not die by suicide. The evidence describes a distribution, not a trajectory.
Nor does the evidence support the view that suicide risk is intrinsic to autism. It points instead to a set of identifiable and largely modifiable contributors, which is where the research effort has concentrated since about 2017.
What the evidence indicates about mechanism
Camouflaging and unmet support need. In 2018, Cassidy, Bradley, Shaw and Baron-Cohen published a study in Molecular Autism comparing 164 autistic adults with 169 general population participants. Seventy-two per cent of the autistic group scored at or above the cut-off used for psychiatric populations, against 33.7 per cent of the comparison group. Three variables independently predicted suicidality after controlling for depression, anxiety and employment status, of which two are specific to autism. The first is camouflaging, meaning the suppression or concealment of autistic characteristics in order to appear socially acceptable. The second is the mismatch between the support a person needed and the support they received. The third, non-suicidal self-injury, was reported over the lifetime by 65%of the autistic group against 29.8%of the comparison group. Autistic women scored higher overall on the camouflaging measure than autistic men.
That camouflaging survives statistical control for depression and anxiety is the significant result. It indicates that the sustained effort of concealment contributes to risk in its own right, rather than acting solely through low mood.
Services that do not reach the person. In 2019, Louise Camm-Crosbie and colleagues, again with Baron-Cohen and Cassidy, surveyed 200 autistic adults in Autism about their experiences of seeking help for mental health difficulties, self-injury and suicidality. The dominant account was of falling between services, with mental health teams treating autism as outside their remit and autism services treating mental health as outside theirs. Participants described waiting times long enough that the crisis had passed before an appointment was offered, and a recurring theme was that being articulate or employed was treated as evidence that support was unnecessary.
Thwarted belonging and perceived burdensomeness. Thomas Joiner's interpersonal theory of suicide proposes that suicidal desire arises where a person experiences both an absence of belonging and a belief that they are a burden to others. Mirabel Pelton and Sarah Cassidy have tested its application, first in relation to autistic traits in a non-clinical sample in Autism Research in 2017, and subsequently in autistic and non-autistic samples, with Baron-Cohen among the co-authors, in the Journal of Autism and Developmental Disorders in 2020. The theory offers a coherent account of why the accumulated experience of being treated as socially incorrect and effortful to others might translate into risk, and it identifies two targets that are open to intervention.
Autistic burnout. Dora Raymaker and colleagues, working within AASPIRE, an academic and community partnership which Raymaker, who is autistic, co-directs, published the first study to characterise autistic burnout empirically, in Autism in Adulthood in 2020. Burnout denotes a state of pervasive and prolonged exhaustion, loss of function and reduced tolerance of sensory input, arising from chronic life stress and a mismatch between expectations and capacity in the absence of adequate support. It is frequently mistaken for depression, and the distinction is clinically consequential because the each of the two call for different responses.
Alexithymia. A meta-analysis by Emma Kinnaird, Catherine Stewart and Kate Tchanturia at King's College London, published in European Psychiatry in 2019, estimated the pooled prevalence of alexithymia at 49.9%in autistic samples against 4.9%in non-autistic samples. Where a person has marked difficulty identifying and describing their own emotional states, the internal signal that ordinarily prompts help-seeking before a crisis does not operate reliably.
What follows from this
The mechanisms above are, with the partial exception of alexithymia, features of the environment and of service design rather than of the person. They are open to change.
Waiting times can be shortened and eligibility criteria reviewed. Environments can be adjusted so that camouflaging is less necessary. Diagnostic assessment can be made available earlier. Psychological therapies can be adapted. Burnout can be identified rather than treated as depression that has failed to respond. Clinicians and families can learn that a composed presentation is not evidence of a settled internal state.
The second article in this series examines why, given the consistency of these findings, autistic distress continues to be missed by services designed to detect it. The third sets out what the emerging intervention evidence supports.
Sources of support
If you are struggling, you do not have to wait until things are worse to ask for help.
• Samaritans. Free, day or night, 365 days a year. Call 116 123, at any hour. The Welsh Language Line, 0808-164-0123
, is open from 7pm to 11pm every day. A Relay UK service is available for d/Deaf and hard of hearing callers, and details are on the Samaritans website. Branches also offer face-to-face support; it is worth telephoning ahead to arrange a time.
• Shout. Free, confidential text support, 24 hours a day, which may suit you better if speaking on the telephone is difficult. Text SHOUT to 85258.
• PAPYRUS HOPELINE247, for anyone under 35 experiencing thoughts of suicide, and for anyone concerned about a young person. Call 0800 068 4141, text 88247, or email pat@papyrus-uk.org.
• Urgent NHS mental health support. In England and Wales, call 111 and select the mental health option. In Scotland, call NHS 24 on 111. In Northern Ireland, Lifeline is available on 0808 808 8000.
• Your GP, who can refer you into local services.
• In an emergency, call 999 or attend your nearest A&E department.
About the author
Esther John, Clinical and Forensic Psychologist, Minds in Session.
Minds in Session provides psychological assessment, therapy and organisational consultancy, with particular expertise in neurodiversity, leadership and workplace mental health.
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