Occurrence and predictors of lifetime suicidality and suicidal ideation in autistic adults

Abstract

In the past 40 years, accumulating evidence suggested that autistic individuals are at an increased risk of suicidal thoughts and behaviors. This study examined the occurrence of various potential risk factors for lifetime suicidal behavior and suicidal thoughts in the past month in a Dutch cohort (Netherlands Autism Register) of autistic individuals using the Suicidal Behaviors Questionnaire (SBQ-R) and the Suicidal Ideation Attributes Scale (SIDAS). Our results show that the majority (80%) of the initial sample ( N = 1164) had thought about or attempted suicide in their lifetime, of which 15% had attempted suicide. In the final sample ( n = 421), backward linear regression analyses identified the following predictors for suicidal behavior: psychiatric comorbidity, loneliness, and higher number of autistic traits, F(3, 240) = 21.22, p < 0.001, with R2 of 0.21. For suicidal thoughts in the past month, psychiatric comorbidity and a higher number of autistic traits were significant predictors, F(2, 241) = 20.34, p < 0.001, with R2 of 0.14. In sum, additional risk markers for suicidal thoughts and behaviors in autistic individuals (e.g. number of autistic traits) should be considered when assessing the suicide risk in autistic individuals. Future research should focus on adapting suicide prevention interventions for autistic individuals, such as addressing loneliness as one of the intervention strategies. Lay Abstract Over the past few years, more and more research is showing that many autistic people are at an increased risk for suicide. In this study, we asked participants from the Netherlands Autism Register, which is longitudinal register including individuals with autism, about their possible experiences with thoughts and feelings about suicide. Specifically, we looked at whether these thoughts and feelings in their lifetime and in the past month were related to various factors (such as their age, gender, and having psychiatric disorder diagnoses). We found that 80% of the participants had experienced thoughts about or even attempted to take their own life at least once throughout their lifetime. Furthermore, in a subgroup of participants, we found that the presence of a psychiatric disorder diagnosis, feelings of loneliness, and a higher number of autistic traits were associated with experiencing suicidal thoughts and feelings in their lifetime. For those who experienced these suicidal thoughts in the past month, we found that having (multiple) psychiatric disorder diagnoses and a higher number of autistic traits were related to more severe and frequent thoughts about suicide in the past month. Our findings show that additional factors in autistic individuals should be considered when assessing the suicide risk, and it brings us one step closer to understanding why suicide is more common for autistic people.