# Integrating Dimensional Personality and Autistic Traits to Predict Suicidal Ideation, Suicide Attempts, and Nonsuicidal Self‐Injury in Autistic Adults

## TL;DR

In autistic adults, low enjoyment of activities and social difficulties are linked to higher risks of suicidal thoughts and self-harm, suggesting the need for targeted screening and support.

## Contribution

This study integrates autism-specific traits and personality dimensions to identify novel predictors of suicidal and self-harming behaviors in autistic adults.

## Key findings

- Lower enjoyment of daily activities and greater social difficulties were consistently linked to higher risk of suicidal ideation, attempts, and NSSI.
- Rapid mood swings were robustly associated with self-harm and more severe suicidal thinking.
- Higher IQ showed a modest protective effect against suicide attempts.

## Abstract

Given the elevated rates of suicidal ideation, suicide attempts, and nonsuicidal self‐injury (NSSI) in autistic adults, we examined whether autism‐informed traits and transdiagnostic personality tendencies jointly relate to these outcomes. One hundred and two adults with clinician‐diagnosed autism completed structured clinical interview assessments of lifetime histories of suicidal ideation, attempts, and NSSI. Predictors were six Comprehensive Autistic Trait Inventory (CATI) subscales and selected Personality Inventory for DSM‐5 Short Form (PID‐5‐SF) domains and facets. We fit CATI‐only, PID‐5 domain, and facet models, then combined significant predictors and refit with age, sex, and IQ as covariates. Shared variance between PID‐5‐SF facet Anhedonia and CATI Social Interactions showed suppression in joint models, and latent variable modeling confirmed that their shared variance—indexing overlapping reward and social disengagement—was the most consistent correlate of risk across outcomes. PID‐5‐SF facet Emotional Lability was robustly related to NSSI and to ideation severity. CATI Self‐Regulatory Behaviors predicted NSSI. PID‐5‐SF domain Disinhibition showed no associations. Higher IQ showed a modest protective effect for attempts. Findings highlight central roles of reward‐related processes and affective volatility, with added contributions from interpersonal strain and self‐regulation. Combining CATI with PID‐5 yields complementary targets for assessment and intervention. Key strengths include a clinician‐diagnosed autistic sample, a rare direct comparison of people with lifetime suicidal ideation vs. suicide attempts, and an integrated trait framework that moves the field beyond prevalence toward trait‐informed risk. Findings support brief screening for anhedonia and emotional lability, autism‐adapted behavioral activation, rapid arousal‐reduction skills, and attention to social communication needs that may impede disclosure and help‐seeking.

In 102 clinician‐diagnosed autistic adults, lower enjoyment of daily activities and greater social difficulties were linked to higher risk of suicidal thoughts, suicide attempts, and self‐harm without intent to die. Rapid mood swings also related to self‐harm and more severe suicidal thinking. These results support brief screening for low pleasure and mood swings, efforts to reduce social strain, and the use of autism‐adapted behavioral activation and quick calming skills.