Overlap of anxiety, depression, irritability and aggressiveness in autism spectrum disorder: an exploratory study using cluster analysis

Purpose This study aims to explore the overlap between symptoms of depression, anxiety, irritability and aggressiveness in autism spectrum disorder (ASD), to measure specific and idiosyncratic emotional responses. Design/methodology/approach A total of 42 high functioning adolescents and adults, between 12 and 39 years old, meeting the diagnostic and statistical manual of mental disorders - 5 criteria for ASD were selected from the InFoR Autism cohort. Data were analyzed in an exploratory way using Hill and Smith and K-medoids cluster analysis. Findings The authors found an aggregation of anxiety, depression, aggressive behaviors and irritability. Cluster analysis was maximized for two groups with 17 and 25 participants, respectively. The first group was characterized by high levels of symptoms of irritability, aggressiveness, hyperactivity and intermediate levels of anxiety and depression. In the first group, participants had significantly higher levels of autistic symptoms considering the social responsiveness scale and repetitive behavior scale-revised scales (relatives' reports) suggesting that a particular group of subjects with a high level of ASD specific symptoms may express anxiety and depression in a specific way based on externalizing behaviors in addition to the common mood and anxiety symptoms. Research limitations/implications Improved understanding of the aggregation of externalized symptoms with symptoms of anxiety and mood disorders in ASD should lead to a better understanding of the underlying mechanisms related to emotion dysregulation in ASD. Practical implications Improved knowledge of the symptoms could lead to enhanced detection of psychiatric comorbidities in ASD. Originality/value The study was based on a transdiagnostic approach of psychiatric symptoms in individuals with ASD. Aggregation and clustering analysis was used to explore naive patterns of these psychiatric symptoms.