Development and Initial Validation of the Japanese Version of the Movie for the Assessment of Social Cognition in Adults With Autism Spectrum Disorder.

AIMS: This study aimed to develop a Japanese version of the Movie for the Assessment of Social Cognition (MASC-J) and to conduct a preliminary evaluation of its reliability and validity in adults with autism spectrum disorder (ASD) compared with healthy controls (HCs). METHODS: Thirty adults with ASD and 30 HCs completed the MASC-J, Reading the Mind in the Eyes Test (RMET), Autism-Spectrum Quotient, and Japanese Adult Reading Test. Internal consistency, test-retest reliability, partial convergent validity with the RMET, and discriminative ability using receiver operating characteristic analysis were examined. RESULTS: MASC-J scores were significantly lower in the ASD group than in the HC group. The MASC-J showed acceptable discriminative ability (area under the curve = 0.804), acceptable internal consistency, and excellent test-retest reliability. In the total sample, MASC-J scores correlated with RMET scores, but this association was not significant within either group. In the ASD group, MASC-J scores were positively associated with estimated full-scale IQ. Overmentalizing and absence-of-mentalizing errors were more frequent in the ASD group, whereas undermentalizing errors did not differ between groups. CONCLUSION: These findings provide preliminary support for the MASC-J as a measure of social cognition in Japanese-speaking adults with ASD.