Risk factors of autistic symptoms in children with ADHD.

Autistic symptoms are frequently observed in children with attention-deficit/hyperactivity disorder (ADHD), but their etiology remains unclear. The main aim of this study was to describe risk factors for increased autistic symptoms in children with ADHD without an autism or autism-spectrum diagnosis. Comorbid psychiatric disorders, developmental delay, current medication, prenatal biological and postnatal psychosocial risk factors as well as parental autistic traits were assessed in 205 children with ADHD. Linear regression models identified maternal autistic traits, current familial risk factors and hyperactive symptoms as predictors of autistic symptoms in children with ADHD. Findings are indicative of possible genetic as well as environmental risk factors mediating autistic symptoms in children with ADHD. An additional validity analysis by ROC, area under the curve (AUC), suggested a cut-off of 11 to differentiate between ADHD and high-functioning ASD by the Social Communication Questionnaire (SCQ).