Exploring the “insight paradox” in Japanese inpatients with schizophrenia: A cluster analysis cross-sectional study based on insight and internalized stigma including comparisons of subjective outcomes

Insight in schizophrenia is a crucial indicator of recovery; however, the "insight paradox" suggests that greater insight may be associated with poorer subjective outcomes. In this exploratory cross-sectional study, we aimed to classify Japanese inpatients with schizophrenia based on insight and internalized stigma and examine differences in personal recovery and self-esteem across the identified groups. Data were collected from 83 participants. Insight and psychiatric symptoms were objectively assessed by a trained researcher, whereas internalized stigma, personal recovery, and self-esteem were measured using self-report questionnaires. Using k-means cluster analysis based on the scores for insight and internalized stigma, four clusters appeared to emerge: "Acceptance," "Paradox," "Unaware," and a potential fourth cluster named "Denial." The Acceptance group demonstrated the highest level of recovery, whereas the Paradox group exhibited the poorest subjective outcomes despite relatively favorable clinical stability. The Unaware group showed poor clinical indicators but positive subjective outcomes, whereas the potential Denial group demonstrated poor outcomes in both domains. These findings provide preliminary evidence for the insight paradox and reveal the potential existence of a unique "Denial" group within the Japanese inpatient context. The results suggest that clinical support initiatives should foster insight as part of self-identity while addressing the potential for increased internalized stigma and poorer subjective outcomes during the process of deepening insight.