Validity of the social responsiveness scale to differentiate between autism spectrum disorders and disruptive behaviour disorders.

Autism spectrum disorder (ASD) as well as oppositional defiant (ODD) and conduct disorder (CD) is characterised by difficulties in social interaction with peers. The Social Responsiveness Scale (SRS) measures reciprocal social behaviour in children and adolescents and was originally developed as a quantitative measure of autistic traits. In the present study, we compare parent-rated SRS scores in children with ODD, CD, and ASD and examine the diagnostic validity of the SRS alone and in combination with additional questionnaires to differentiate between groups. We hypothesize that the SRS better differentiates ASD and typically developing controls (TD) than ASD and the disruptive behaviour disorders ODD and CD. The sample consists of three clinical groups: ASD without comorbid intellectual delay (N = 55), ODD/CD (N = 55), and TD (N = 55), between 6 and 18 years. The groups were matched by age, sex, and IQ. SRS scores were compared for the three groups. Sensitivity and specificity of the SRS total and sub-scores were examined by receiver operating characteristics (ROC) analyses. Logistic regression analyses were calculated for estimating the rate of correctly specified individuals. The SRS differentiated excellently between ASD and TD (ROC-AUC = 1.00), but sensitivity and specificity were considerably lower when ASD was compared with ODD/CD (ROC-AUC = 0.82). A combination of three parent-rated questionnaires resulted in an improved validity to differentiate ASD and ODD/CD. For clinical screening purposes in children suspicious of ASD and/or ODD/CD, the SRS should be used in combination with additional disorder-specific questionnaires to improve the rate of correct classification of both disorders.