"A circle and a triangle dancing together": Alteration of social cognition in schizophrenia compared to autism spectrum disorders.

Difficulties in social cognition are present both in persons with schizophrenia (SCZ) and persons with autism spectrum disorders (ASD). However, qualitative similarities and differences in this field remain unclear. The aim of this study was to explore attribution of intentionality in patients with recent onset SCZ in comparison to patients with high functioning ASD, and to explore relationships between alterations in attribution and clinical profile. Animated shapes are a non-verbal Theory of Mind (ToM) task involving the interpretation of geometric figure interactions in three conditions: random, goal-directed and ToM. We compared 51 young adults with SCZ, 32 with ASD and 23 healthy controls (HC) matched for age and gender. In random, goal-directed and ToM conditions, persons with SCZ attributed less intentionality with less appropriate answers than HC, while the same anomalies were only found in the ToM condition in persons with ASD. In SCZ, thought and langage disorganization and earlier age at onset were correlated with intentionality score in the random condition. Moreover, a mixed ToM impairment was found in SCZ, combining undermentalizing (for movements involving a mental state) similar to what was found in ASD, and overmentalizing (for random movements), related to dizorganization and precocity of the first psychotic episode. In the frame of the hypothesis of a continuum, these results underline both similarities and differences between autism and schizophrenia.