Association between autism spectrum disorder and intentional self-harm

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by persistent challenges in communication and social interaction and, often accompanied by restricted and repetitive patterns of behavior and interests. The reported prevalence of ASD in the United States has tripled in the past two decades. Recent studies indicate that ASD is associated with increased self-injurious behaviors. The purpose of this study is to assess the excess risk of intentional self-harm associated with ASD.

Using a repeated cross-sectional study design, we analyzed data from the 2016-2020 Nationwide Emergency Department Samples (NEDS), the largest all-payer emergency department (ED) database in the United States. ED visits for intentional self-harm were identified using the ICD-10-CM external cause-of-injury matrix. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) of ED-treated intentional self-harm associated with ASD in the presence or absence of co-occurring attention-deficit hyperactivity disorder (ADHD) and/or intellectual disability (ID) were estimated through multivariable logistic regression.

The 2016-2020 NEDS recorded an unweighted total of 159,590,866 ED visits, of which 2,570,446 (1.6%) were related to intentional self-harm. Using weighted data, intentional self-injury accounted for 2.3% of ED visits made by patients with a diagnosis of ASD, 3.9% of ED visits by patients with a diagnosis of ADHD, and 3.3% of ED visits by patients with a diagnosis of ID. Compared to patients without ASD or ADHD/ID, patients with ASD alone had a 65% increased odds of intentional self-harm (aOR = 1.65; 95% CI: 1.60, 1.70); in addition, patients with ADHD/ID but no ASD a 186% increased odds (aOR = 2.86; 95% CI: 2.83, 2.88), and patients with both ASD and ADHD/ ID a 170% increased odds (aOR = 2.70; 95% CI: 2.58, 2.82) of intentional self-harm. Poisoning accounted for 82.3% of the intentional self-harm-related ED visits among patients without ASD and 61.0% of intentional self-harm-related ED visits among patients with ASD.

ASD is associated with a significantly increased risk of ED-treated intentional self-harm, particularly in patients with co-occurring ADHD or ID. Poisoning from psychotropic and other pharmaceutical drugs is the leading mechanism of intentional self-harm.