The animated assessment of theory of mind for people with schizophrenia (AToMS): development and psychometric evaluation

Theory of mind (ToM) deficits in people with schizophrenia have been reported and associated with impaired social interactions. Thus, ToM deficits may negatively impact social functioning and warrant consideration in treatment development. However, extant ToM measures may place excessive cognitive demands on people with schizophrenia. Therefore, the study aimed to develop a comprehensible Assessment of ToM for people with Schizophrenia (AToMS) and evaluate its psychometric properties. The AToMs was developed in 5 stages, including item formation, expert review, content validity evaluation, animation production, and cognitive interviews of 25 people with schizophrenia. The psychometric properties of the 16-item AToMS (including reliability and validity) were then tested on 59 people with schizophrenia. The newly developed animated AToMS assesses 8 ToM concepts in the cognitive and affective dimensions while placing minimal neurocognitive demands on people with schizophrenia. The AToMS presented satisfactory psychometric properties, with adequate content validity (content validity index = 0.91); mostly moderate item difficulty (item difficulty index = 0.339-0.966); good discrimination (coefficients = 0.379-0.786), internal consistency (Cronbach's α = 0.850), and reliability (intraclass correlation coefficient = 0.901 for test-retest, 0.997 for inter-rater); and satisfactory convergent and divergent validity. The AToMS is reliable and valid for evaluating ToM characteristics in people with schizophrenia. Future studies are warranted to examine the AToMS in other populations (e.g., people with affective disorders) to cross-validate and extend its utility and psychometric evidence.