Autism Spectrum Disorder, Attention-Deficit/Hyperactivity Disorder, Tic Disorder, and Obsessive-Compulsive Disorder...

Neurodevelopmental conditions frequently co-occur with eating disorders (EDs). This study aimed to investigate the occurrence of attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), tic disorder (TD), and obsessive-compulsive disorder (OCD) in individuals with EDs and their full and half siblings.

Study population comprised all individuals born in Finland between 1991 and 2001 with a recorded diagnosis of the following ICD-10 EDs (N = 4240): anorexia nervosa (AN; F50.0/F50.1), bulimia nervosa (BN; F50.2/F50.3), and other/unspecified EDs (F50.8/F50.9). Population controls without ED (N = 16,494) and full and half siblings of participants with ED and controls (N = 36,301) were included. Conditional logistic regression was applied in analysis.

Individuals with AN had increased occurrence of ASD, ADHD, and OCD compared to population controls (Odds ratios [ORs]: 6.62 [95% CI 4.21-10.39]; 3.30 [95% CI 2.33-4.69]; 10.67 [95% CI 7.07-16.10], respectively). Individuals with other/unspecified EDs had increased occurrence of ASD, ADHD, TD, and OCD (ORs: 9.06 [95% CI 5.5-14.77]; 2.78 [95% CI 1.92-4.01]; 4.68 [95% CI 1.94-11.32]; 7.64 [95% CI 4.92-11.87], respectively). The occurrence for ASD was particularly pronounced in males with other/unspecified EDs (OR 32.40 [95% CI 9.78-107.39]). Compared to full siblings of population controls, full siblings of individuals with AN had two-fold odds for ASD and three-fold odds for OCD; full siblings of individuals with other/unspecified EDs had 2-3-fold odds for ASD, ADHD, TD, and OCD.

Individuals with EDs have a high occurrence of neurodevelopmental conditions, also extending to their full siblings. These findings provide detailed characterization of comorbidity and the familial aggregation of these conditions.