Autistic adolescents are more likely to experience suicidal thoughts and behaviors and nonsuicidal self-injury than non-autistic adolescents, per caregiver- and self-report on single-item questionnaires. Comprehensive, clinician-rated measures of suicide risk have not been used to measure suicidal thoughts and behaviors and nonsuicidal self-injury in autistic youth despite greater parent-child rating discrepancies among autistic youth than their non-autistic peers. The Columbia Suicide Severity Rating Scale is a widely used, clinician-rated measure of suicide risk that has not been tested with autistic youth. In this study, the Columbia Suicide Severity Rating Scale was employed to assess suicidal thoughts and behaviors and nonsuicidal self-injury in a community sample of 239 early adolescents (10:0-13:9 years old), of whom 138 youth were autistic and 101 were not autistic. Multiple analyses examined diagnostic (autistic vs non-autistic) and sex-based (male vs female) differences in suicidal thoughts and behaviors and nonsuicidal self-injury, as well as youth consistency in reporting across self- and clinician-rated measures. Findings show that a greater proportion of autistic youth reported lifetime suicidal thoughts and nonsuicidal self-injury than non-autistic youth; however, there were no sex-based differences. The majority of non-autistic youth were consistent in reporting suicidal thoughts on self- and clinician-rated measures; however, nearly one in five autistic youth disclosed suicidal thoughts on a self-report measure but not to a psychiatrist on the Columbia Suicide Severity Rating Scale. Findings suggest that autism diagnostic status, but not sex, confers significant risk for suicidal thoughts and behaviors and nonsuicidal self-injury in early adolescents and that the Columbia Suicide Severity Rating Scale may be a useful measure of suicide risk for some autistic youth, but it may not detect all autistic youth experiencing suicidal thoughts.
Keywords: autism; early adolescent; nonsuicidal self-injury; sex; suicide.