Self-Harm and Suicidality Experiences of Autistic and Non-Autistic Adults in Midlife and Older Age

Background Suicide has been reported as a leading cause of premature death in autistic populations. Additionally, risk of suicidality is often found to increase with age in the general population. Despite this, suicidality has seldom been explored in autistic populations in midlife and older age. This study investigates the self-reported prevalence of self-harm and suicidality in autistic people in midlife and older age compared to an age- and gender-matched non-autistic comparison group. Methods In total, 388 participants (autistic n = 222, 44% men) aged 40–93 years (mean = 60.9 years) from the AgeWellAutism study completed questionnaires related to experiences of suicidal ideation, self-harming thoughts, deliberate self-harm, and suicidal self-harm. Group, gender and age differences were examined chi-square and linear regression analyses. Results The autistic group reported significantly higher rates of suicidal ideation, self-harming thoughts, deliberate self-harm, and suicidal self-harm than the non-autistic comparison group. When considering gender differences in the autistic group (but not the non-autistic group due to limited sample size), autistic women reported significantly higher rates of suicidal ideation and suicidal self-harm compared to autistic men; no other gender differences were found. When considering age differences, autistic people in old age were more likely to have had thoughts of self-harm, to have deliberately self-harmed, and to have experienced suicidal self-harm than autistic people in midlife. Limitations: The AgeWellAutism study is a cross-sectional convenience sample that relies on self-report. Survivor bias may also influence findings, as the study design would exclude those who have died by suicide, potentially leading to an underestimation of suicidality. Conclusions Autistic adults may be particularly susceptible to experiences of self-harm and suicidality in midlife and older age, particularly autistic women. Additionally, autistic people in old age were also more likely to experience suicidality (including recent experiences) than autistic people in midlife. These findings highlight the urgent need for targeted suicide prevention strategies and mental health interventions for autistic adults in midlife and older age, particularly autistic women and older people.