25005
Increased Risk for Self-Harm in Autism: Preliminary Findings from the Stockholm Youth Cohort

Saturday, May 13, 2017: 1:27 PM
Yerba Buena 3-6 (Marriott Marquis Hotel)
I. Bubak1, D. Rai2, S. Idring Nordstrom3, M. Lundberg4, I. Culpin5, C. Dalman4 and C. Magnusson4, (1)Department of Public Health, Stockholm County Council and Karolinska Institutet, Stockholm, Sweden, (2)School of Social and Community Medicine, University of Bristol, Bristol , United Kingdom of Great Britain and Northern Ireland, (3)Department of Public Health Sciences, Stockholm, SWEDEN, (4)Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden, (5)School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
Background:

Recent evidence suggests that mortality from suicide is increased in autism spectrum disorder (ASD), and particularly in ASD without intellectual disability (ID). Self-harm i.e. self-poisoning or self-injury irrespective of suicidal intent, is the strongest known predictor for subsequent suicide. Self-harm is, however, poorly studied in ASD including whether there are patterns in self-harm methods of prognostic relevance for suicide. In addition, little is known about how co-morbid conditions such as ID and Attention Deficit Hyperactivity Disorder (ADHD) affect risk of self-harm.

Objectives:

To determine the relationship between ASD and self-harm in a large total population study. To investigate risk and protective factors for self-harm in ASD, with emphasis on co-morbid ID and ADHD. 

Methods:

We conducted a total population study using the Stockholm Youth Cohort (N=696,612). Prospectively recorded data for probands followed-up from 0 to a maximum of 27 years by 2011, and their first and second-degree relatives, was collected through record linkage. A total of 11,663 individuals with ASD were identified. Hospital admissions with discharge diagnoses ICD-10 X60-X84 and Y10-Y34 denoted self-harm. We used multivariable Cox proportional hazards regression models to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) of self-harm, overall and categorized as self-harm by poisoning, self-cutting and severe self-harm (including hanging, strangulation, firearm, drowning, jumping from high place/in front of moving objects).

Results:

A diagnosis of ASD was strongly associated with risk of hospital admission for any self-harm

(adjusted HR 4.5, 95% CI 3.8-5.4), self-poisoning (aHR 4.6, 95% CI 3.7-5.6), self-cutting (aHR 5.6 95% CI 3.8-8.3)

and severe self-harm (aHR 5.7, 95% CI 2.5-13.0). This risk increase was even further marked for ASD with co-morbid ADHD for any self-harm (aHR 8.5, 95% CI 7.0- 10.3), self-poisoning (aHR 7.6 95% CI 6.2-9.2), self-cutting (aHR 9.6 95%CI 6.6-13.9) and severe self-harm (aHR 16.1 95% CI 8.6-30.4). In contrast, ASD with ID was not associated with hospital presentations for self-harm.

Conclusions:

These preliminary findings indicate that individuals with ASD have an elevated risk for engaging in self-harm in adolescence and young adulthood, and particularly in severe self-harm. Co-occurring ADHD appears to aggravate this risk, which suggests that identification and treatment of ADHD in ASD may be important for suicide prevention. Co-occurring ID, on the other hand, appears protective. Overall, patients with ASD should be considered a risk group for self-injurious behavior and should be given special attention in clinical settings.