Psychometric properties of the Japanese version of the Beck Cognitive Insight Scale: Relation of cognitive insight to clinical insight

Aim: Insight in schizophrenia is considered to have a multidimensional construct, and cognitive insight is thought to be an important dimension of insight: an ability to evaluate and correct one's own distorted beliefs and misinterpretations. The Beck Cognitive Insight Scale (BCIS) was developed to measure cognitive insight, and studies have shown that cognitive insight is associated with several clinical features in schizophrenia. The aim of the present study was to develop a Japanese version of the BCIS (BCIS-J) and assess the psychometric properties of this instrument. Methods: The BCIS-J was completed by university students (n = 183) and patients with schizophrenia (n = 30). The Japanese version of the Schedule for the Assessment of Insight was used to measure clinical insight in patients with schizophrenia, and its association with the BCIS-J was investigated. Results: Factor analysis in the university students indicated that the BCIS-J was composed of two factors, self-reflectiveness and self-certainty, as was seen in the original BCIS. The relation between the specific dimensions of clinical insight and each component of the BCIS-J in patients with schizophrenia indicated that overconfidence in their belief or judgment may be involved in their attitude to treatment and openness to feedback, and objectivity might be essential to attribute one's symptoms as part of mental illness. Conclusions: The BCIS-J is a reliable and valid instrument to measure cognitive aspects of insight and appears to complement clinical insight scales.