Reliability and Validity of the Japanese Version of the Inventory of Psychotic-Like Anomalous Self-Experiences.
Dan Nakamura, Masafumi Mizuno, David C Cicero, Yu Arai, Hirohisa Suzuki, Shunsuke Hirose, Takahisa Kasai, Shutaro Sugita, Yoshifumi Nakamura, Stephen J. Wood, Andrea Polari, Takahiro Nemoto, Barnaby Nelson
International Journal of Methods in Psychiatric Research September 1, 2026 DOI: 10.1002/mpr.70099 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Cross-sectional validation study Peer reviewed |
|---|---|
| Sample size | 182 |
| Population | 83 individuals with schizophrenia and 99 healthy controls in Japan |
| Measures | Inventory of Psychotic-Like Anomalous Self-Experiences (IPASE), PANSS, YMRS |
| Keywords | Humans Reproducibility of results Roc curve Psychotic disorders Schizophrenia Psychometrics Schizophrenic psychology Middle aged Japan Female Young adult Basic self‐disturbance |
| Key findings | The Japanese version of the IPASE showed good internal consistency (Cronbach's alpha above 0.80) and discriminated schizophrenia from healthy controls with an AUC of 0.851. IPASE scores were significantly higher in the schizophrenia group and correlated positively with PANSS positive, general psychopathology, and total scores, which the authors present as support for convergent validity. |
Abstract
Objectives: Basic self-disturbance is an abnormality in subjective self-experience and a core feature of schizophrenia. The Inventory of Psychotic-Like Anomalous Self-Experiences (IPASE) is a self-report measure designed to assess basic self-disturbance. Despite its clinical utility, a Japanese version has not yet been established. This study aimed to develop a Japanese version of the IPASE and evaluate its reliability and validity.
Methods: The study included 182 participants (83 individuals with schizophrenia and 99 healthy controls). The Japanese version of the IPASE was administered to all participants, along with the PANSS and YMRS, to assess validity.
Result: All IPASE domain scores and the total score were significantly higher in the schizophrenia group than in healthy controls. The IPASE total score showed good internal consistency (Cronbach's α > 0.80). In the schizophrenia group, the PANSS positive subscale, general psychopathology subscale, and total scores were all significantly positively correlated with IPASE scores. These positive correlations with the positive subscale support convergent validity. ROC analysis indicated that the IPASE total score had good discriminative ability for schizophrenia diagnosis (AUC = 0.851).
Conclusion: The Japanese version of the IPASE demonstrated high reliability and validity.
Citations in the library
Cites 5
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