A systematic review and meta-analysis of suicidality in autistic and possibly autistic people without co-occurring intellectual disability

Abstract

Background Suicidality is highly prevalent in autistic people without co-occurring intellectual disabilities, and high autistic traits are found in adults who have attempted suicide. However, prevalence rates for both autistic and possibly autistic people have not been synthesised meta-analytically. Aims To (1) calculate pooled prevalence estimates of suicidality in autistic people and possibly autistic people without co-occurring intellectual disability; (2) evaluate the influence of participant and study level characteristics on heterogeneity; and (3) determine the quality of evidence. Methods Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed. PsycINFO, Embase, MEDLINE and Web of Science were systematically searched from 1992 to January 25, 2022. Empirical quantitative studies reporting prevalence of suicidal ideation, suicide plans, or suicide attempts and behaviours were considered for inclusion. Random effects models were used to estimate pooled prevalence of each suicidality outcome with 95% confidence intervals. Heterogeneity was explored using sensitivity and moderator analyses. Results Data from 48,186 autistic and possibly autistic participants in 36 primary studies were meta-analysed. Pooled prevalence of suicidal ideation was 34.2% (95% CI 27.9–40.5), suicide plans 21.9% (13.4–30.4), and suicidal attempts and behaviours 24.3% (18.9–29.6). High levels of heterogeneity (I2 > 75) were observed in all three analyses. Estimates did not differ between autistic or possibly autistic samples. Geographical location (p = 0.005), transgender or gender non-conforming samples (p < 0.001) and type of report (p < 0.001) significantly moderated suicidal ideation, whereas age group (p = 0.001) and measure of suicidality (p = 0.001) significantly moderated suicide plans. There was a significant association between the proportion of male participants and prevalence of suicide plans, with a decrease in the proportion of males for every unit change of suicide plan prevalence (p = 0.013). No variables were found to moderate estimates of suicide attempts and behaviours. Conclusions The results confirm suicidality is highly prevalent in both autistic and possibly autistic people without co-occurring intellectual disability and highlights potential moderators. Possibly autistic individuals require more attention in clinical and research considerations going forward to further understand and prevent suicide in both groups.

Self-Harm Events and Suicide Deaths Among Autistic Individuals in Ontario, Canada

“…For self-injurious behavior specifically, the pooled prevalence was 42% (95% CI, 38%-47%) among autistic people and the cumulative incidence among individuals with developmental disabilities (including autism) was 22% over 1 to 8 years . Our findings corroborate these previous observations and highlight the importance of evaluating self-harm events and suicide death separately, stratified by sex, and accounting for confounders informing risk mechanisms—particularly psychiatric illnesses—especially because the latest meta-analyses could not summarize their roles owing to the lack of primary data …”

“…5 Our findings corroborate these previous observations and highlight the importance of evaluating self-harm events and suicide death separately, stratified by sex, and accounting for confounders informing risk mechanismsparticularly psychiatric illnesses-especially because the latest meta-analyses could not summarize their roles owing to the lack of primary data. 4,8 Our findings of increased self-harm risks among autistic individuals are consistent with population-based findings from Sweden, 15,17 Denmark, 18 Finland, 19 Taiwan, 20 the UK, 22 and the US [11][12][13] that autism diagnosis is independently associated with risk of self-harm or suicide attempts, but the associations of self-harm or suicide attempts with psychiatric diagnoses are substantial and often larger than that of autism. Risks for suicidal behaviors span predisposing factors (eg, genetics, early-life adversity), developmental factors (eg, anxiety, impulsivity, executive dysfunction), and precipitating factors (eg, psychiatric illnesses), as well as social-contextual determinants (eg, social isolation, poor mental health care, access to lethal means).…”

“…Autistic individuals experience higher mortality than nonautistic individuals across natural and unnatural causes . Among potentially preventable causes, suicide death and precursory self-harm events occur at higher rates among autistic individuals than nonautistic individuals . Meta-analyses show that autistic individuals have over 3-fold greater odds than nonautistic individuals of experiencing self-injurious behavior, suicidal ideation, suicide attempt, or suicide death .…”

A short-term “behavioural support” service for autistic adults without an intellectual disability: a pilot evaluation

“…Autistic people are more likely to experience mental health problems than the general population (Lai et al, 2019) and at a greater severity (Newell et al, 2023). A range of factors have been proposed to explain this difference, including biological mechanisms (Juranek et al, 2006), barriers and adverse events associated with accessing mainstream health services (Doherty et al, 2022) and psychosocial factors such as stigma, trauma and difficulties "fitting in" to neurotypical society (Cooper et al, 2017;Peterson et al, 2019;Beck et al, 2020).…”

Is camouflaging autistic traits associated with defeat, entrapment, and lifetime suicidal thoughts? Expanding the Integrated Motivational Volitional Model of Suicide

“…Autism and autistic traits are not currently considered in models of suicide (Cassidy, 2020). Yet, research shows that autism diagnosis and autistic traits are associated with increased risk of suicidal thoughts and behaviors (e.g., Cassidy et al, 2014, 2022; Cassidy, Bradley, Shaw, et al, 2018; Gallyer et al, 2020; Hedley et al, 2021; Hedley & Uljarević, 2018; Newell et al, 2023; Paquette‐Smith et al, 2014; Pelton & Cassidy, 2017; Takara & Kondo, 2014). However, there is comparatively little research into why this is the case (Cassidy, Robertson, et al, 2020; Cassidy & Rodgers, 2017).…”