Sex differences in self-harm and suicide in young autistic adults.

INTRODUCTION: Both suicide and self-harm are disproportionately common in autistic people. Sex differences in risk of self-harm and suicide are observed in the general population, but findings are mixed for autistic people. Self-cutting may be a particularly risky self-harm behaviour for suicide in autistic people. We aimed to explore sex differences and differences in method of self-harm in the association between self-harm and suicide in autistic and non-autistic adolescents and young adults. METHODS: We used a total population register of 2.8 million Swedish residents. Participants were followed from age 12 until December 2021 for medical treatment because of self-harm, and death from suicide. We used Cox proportional hazard regression models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for risk of death from suicide following self-harm, and Relative Excessive Risk due to Interaction (RERI) to explore the interaction between self-harm and autism in females and males. RESULTS: We identified 85,143 autistic individuals (31,288 female; 53,855 male) and 2,628,382 non-autistic individuals (1,286,481 female; 1,341,901 male) aged 12-37 years. Incidence of suicide following self-harm was higher in autistic males (incidence per 100,000 risk-years = 169.0 [95% CI 135.1, 211.3]) than females (125.4 [99.4, 158.3]). The relative risk was higher for autistic females (HR 26.1 [95% CI 20.2, 33.7]) than autistic males (12.5 [9.9, 15.8]). An additive effect of both autism and self-harm was observed in both females (RERI = 9.8) and males (2.0). Autistic individuals who self-harmed through cutting were at greatest risk of death from suicide (HR 25.1 [17.9, 35.2]), compared to other methods. CONCLUSION: Autistic males and females are at increased risk of death from suicide following severe self-harm, particularly self-cutting.

Autism and self-harm: A population-based and discordant sibling study of young individuals.

OBJECTIVE: Self-harm among young autistic individuals is a clinical challenge, and the risk of premature death by suicide is strongly increased in this group. Using the advantage of total-population and family-based data, we investigated whether autism per se is a risk factor for self-harm independently of psychiatric comorbidities and how it differs from self-harm in non-autistic individuals. METHODS: We used The Stockholm Youth Cohort, a total-population register study, including all residents in Stockholm County aged 0-17 years between 2001 and 2011.Study participants were followed from age 10 to 27 for hospital admissions because of self-harm. We used modified Poisson regression to calculate relative risks (RR) using robust standard error to derive 95% confidence intervals (CI). RESULTS: In all, 410,732 individuals were included in the cohort (9,070 with a diagnosis of autism). Autistic individuals had a fivefold increased adjusted relative risk of self-harm (RR 5.0 [95% CI 4.4-5.6]). The risk increase was more pronounced for autism without intellectual disability and particularly high for self-cutting 10.2 [7.1-14.7] and more violent methods 8.9 [5.2-15.4]. The association between autism and self-harm was independent of, but clearly exacerbated by comorbid psychiatric conditions. It was of similar magnitude as risks linked to these conditions per se, and not explained by shared familial factors. CONCLUSION: Self-harm severe enough to present to medical services is as common in autistic youth as in those with depression or ADHD. Potentially more lethal methods are more likely to be used of autistic self-harmers.

Measuring clinical outcomes in children with pediatric acute-onset neuropsychiatric syndrome: data from a 2-5 year follow-up study.

BACKGROUND: It is unclear how to best measure the complex symptom presentation of pediatric acute-onset neuropsychiatric syndrome (PANS). METHODS: Well-characterized participants of a 2-5 year follow-up study (n = 34; 56% male) underwent clinical evaluations and completed scales assessing global symptom severity, functional impairment and specific psychiatric symptoms. We explored inter-correlations between the measures and used intraclass correlation coefficients to evaluate the agreement between clinician-, parent- and child ratings of the same constructs. RESULTS: Ratings on symptom-specific measures varied largely between participants. Agreement between informants was excellent on functional scales, fair-to-moderate on global severity scales and mixed on symptom-specific scales. Clinician-rated global and functional measures had stronger inter-correlations with parent- and child-rated functional measures than with symptom-specific measures. CONCLUSIONS: General instruments assessing global severity and functioning are well suited for the assessment and follow-up of PANS, but should be complemented by symptom-specific scales representative of core symptoms.