Phenotypic continuum between autism and schizophrenia: Evidence from the Movie for the Assessment of Social Cognition (MASC).

Schizophrenic (SCZ) and autism (ASD) spectrum disorders share several features including social cognition impairments. In SCZ, the link between symptomatic dimensions and social cognition deficits remains unclear. The Movie for the Assessment of Social Cognition (MASC) test, available in several languages including English, investigates mental state attribution capabilities in complex interpersonal situations. After its translation into French, we used MASC to direct compare social cognition in 36 young participants with SCZ to 19 with ASD and 20 healthy controls (HC) matched for gender, age (18-25y.o.) and level of education. The MASC discriminated each group from the others, patients with SCZ exhibiting difficulties compared to ASD (MASC total score 28.1 (4) and 24.2 (6.6), respectively; p<.001). In the whole sample, MASC scores were inversely correlated with autistic traits, evaluated by autism quotient, and with disorganization symptoms. Finally, in SCZ, over-mentalizing difficulties were correlated with age at disease onset. Our results demonstrate the validity of the French version of the MASC and bring direct evidence supporting the hypothesis of a phenotypic continuum between autism and schizophrenia.