The BAT: A videotaped battery to assess theory of mind in schizophrenia.

The ability of attributing mental states to oneself and to the others (theory of mind, ToM) is impaired in schizophrenia. ToM is not a monolithic function, it includes different capacities: some implies the decoding of affective states, others the reasoning about mental states. We have developed the BAT, a Battery to Assess Theory of mind abilities in adult psychotic subjects in an ecological audiovisual format. The performance on the BAT and three other test of social cognition was compared in a sample of schizophrenic patients with a control group. The samples were matched in terms of age and premorbid IQ. The BAT was sensitive to detect the ToM impairments in schizophrenia, showed good internal consistency and concurrent validity. The area under the ROC curves established a cutoff point that would correctly classify controls and patients in a 96.6% of cases. The factorial analysis isolated two factors: empathy and reasoning, with a good adjustment. Our results showed that the BAT could be a valid, ecological and usable tool to assess ToM in psychotic patients, with good psychometric properties, that would allow obtaining a more complete profile of their impairment.