The relevance of the interpersonal theory of suicide for predicting past-year and lifetime suicidality in autistic adults

Abstract

Background While there are known risk factors for suicidality in autistic adults, these are often unconnected from theoretical frameworks that might explain why risk is elevated and guide clinical interventions. The present study investigated the relevance of constructs from the Interpersonal Theory of Suicide (ITS), including perceived burdensomeness, thwarted belongingness and acquired capability for suicide, and explored mechanisms through which certain risk factors (relationship status, age at diagnosis) might elevate suicide risk. Methods Autistic adults (n = 314) completed an online study including measures of depression, anxiety and constructs from the ITS. Linear and multinomial regression analysis disentangled contributions of ITS variables from effects of depression and anxiety for past-year suicide ideation, past-year and lifetime suicide attempts. Mediation analyses examined associations between risk factors and these suicide outcomes via mechanisms proposed by the ITS. Results Past-year suicide ideation was associated with burdensomeness, mental rehearsal of suicide plans (a facet of acquired capability), and depression. Greater feelings of burdensomeness, and reduced fear of death, marked out participants who had attempted suicide in comparison to those who had experienced suicide ideation in the past year. Relationship status was indirectly associated with past-year suicide ideation via the mediators of depression and burdensomeness, and was associated with past-year attempts via its effect on ideation. Age at diagnosis was unrelated to any variables. Limitations Cross-sectional research is insensitive to causality and temporal dynamics, which is likely why interaction hypotheses from the ITS were unsupported. Normative measures may be invalid in autistic samples. There was no control group. The autistic sample was unrepresentative of the whole population, particularly autistic people with intellectual disabilities, ethnic/racial minorities, and gender minorities. Conclusions Perceived burdensomeness and acquired capability appear potentially important to suicide in autistic people, and may mediate the effects of some risk factors. Future research should explore the temporal dynamics of suicide trajectories in longitudinal, prospective designs.

Non-suicidal self-injury and its relation to suicide through acquired capability: investigating this causal mechanism in a mainly late-diagnosed autistic sample

“…The autistic sample ( n = 314) was the same as that described in a previous study [ 54 ]. They were recruited via advertisement on social media, Autistica’s research network and the Cambridge Autism Research Database; we also contacted participants on our mailing lists from previous studies [ 22 , 31 ].…”

“…Ethical permission for the study was granted by the Science and Technology Faculty panel of Bournemouth University. Data for the present analysis were collected between July 2020 and March 2021 as part of a larger online study which involved a number of additional standardised questionnaires (see [ 54 ]). We describe only the measures relevant to the present analysis.…”

“…Considering the previous lack of association between how autistic participants felt about their NSSI and their higher suicide risk [ 31 ], the present study aimed primarily to re-investigate the association between NSSI and suicide attempts in autistic and non-autistic adults with particular attention to acquired capability as the hypothesised mediator of this relationship. There is a paucity of literature concerning the development and significance of acquired capability in relation to suicide in autistic people, though three studies have drawn tentative links between acquired capability and suicide attempts [ 52 – 54 ]. One of these, an analysis addressing a different question, included the same autistic sample as the present investigation: it highlighted the potential relevance of reduced fear of death and mental rehearsal of suicide plans for suicide attempts [ 54 ].…”

“…There is a paucity of literature concerning the development and significance of acquired capability in relation to suicide in autistic people, though three studies have drawn tentative links between acquired capability and suicide attempts [ 52 – 54 ]. One of these, an analysis addressing a different question, included the same autistic sample as the present investigation: it highlighted the potential relevance of reduced fear of death and mental rehearsal of suicide plans for suicide attempts [ 54 ]. The present study, which includes a comparison group, aimed to consequently expose differences in the strength of relationships between NSSI, acquired capability and suicide attempts.…”

Correction to: The relevance of the interpersonal theory of suicide for predicting past-year and lifetime suicidality in autistic adults

“…Following publication of the original article [ 1 ], the authors reported missing information in the ‘Acknowledgements’ section. The corrected ‘Acknowledgements’ section reads:…”