Quantifying Research Domain Criteria Social Communication Subconstructs Using the Social Communication Questionnaire in Youth

Research Domain Criteria (RDoC) has posited a set of social dimensions that could be useful in identifying sources of individual variation in social impairments across neurodevelopmental disorders. The current investigation aimed to derive estimates of the RDoC social constructs from the Social Communication Questionnaire (SCQ) and examine whether RDoC social processes, as captured by the SCQ, are best represented by a dimensional, categorical, or hybrid model. Individual SCQ items from 4 databases were combined resulting in a total of 26,407 individuals (M-age = 8.13 years, SDage = 4.19; 69.1% male). The sample consisted of 60.0% of individuals with autism spectrum disorder (ASD), 6.8% with a range of neurodevelopmental disorders and 33.2% of siblings of individuals with ASD. Comparison of a range of factor solutions through the use of exploratory structural equation modeling and confirmatory factor analysis indicated that a 3-factor structure with separate attachment and affiliation, production of nonfacial and facial communication factors provided excellent fit to the data (comparative fit index = .989, Tucker-Lewis index = .984, root mean square error of approximation = .045). and robustness across clinical groups, age, sex, and verbal status. Comparison between the best-fitting factor analysis, latent class analysis, and factor mixture analysis solutions demonstrated that the RDoC social processes domain is best represented as dimensional. Our findings show promise for capturing some of the important RDoC social constructs using the SCQ but also highlight crucial areas for the development of new, dedicated dimensional measures.