The Network Structure of Irritability and Aggression in Individuals with Autism Spectrum Disorder

Irritability and aggression (IA) are highly prevalent in individuals with autism spectrum disorder (ASD). Although clinical correlates of IA in this population have been previously examined, findings from existing studies capturing symptoms as a set of latent variables do not fully explain meaningful associations between the symptoms themselves. In the present study, we conducted network analysis which conceptualizes mental health difficulties as a complex network of directly associated symptoms in 2612 individuals who were diagnosed with ASD through rigorous diagnostic assessment and who were enrolled in the Simons Simplex Collection. Using the Aberrant Behavior Checklist, a validated scale, we investigated the network structure of IA and tried to identify bridge symptoms that link IA and other symptom domains. In our analysis, irritability symptoms had stronger and more direct associations with other nodes than aggression symptoms did. Additionally, depressed mood and oppositionality were identified to function as bridge symptoms. The network structures did not differ between individuals with and without intellectual disability. Our findings indicate that addressing these bridge symptoms through integrated care combining different modalities of treatment could ease the complicated symptom network and thereby reduce IA symptoms in individuals with ASD.