Tetsuo Miyakoshi

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 ones 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.

Clinical practice and research activities for early psychiatric intervention at Japanese leading centres.

Aim: To describe clinical practice and research activities for early psychiatric intervention in Japan, a country with a huge number of psychiatric beds and a history of long‐stay, hospital‐based psychiatry.

A naturalistic longitudinal study of at-risk mental state with a 2.4 year follow-up at a specialized clinic setting in Japan

OBJECTIVE The notion of at-risk mental state (ARMS) is valuable for identifying individuals in a putative prodromal state of psychosis and for reducing conversion risk by pharmacological and psychological interventions. However, further systematic study is required because 1) diagnostic reliability in various clinical settings is not yet established; 2) predictive ability is insufficient; 3) optimal interventions in diversified populations are elusive; and 4) little evidence from non-Western regions exists. METHODS A naturalistic longitudinal study was conducted at a specialized clinic for early psychosis at a university hospital in Sendai, Japan. Individuals with ARMS (n=106) were recruited and followed up with case-by-case treatment. RESULTS Two-thirds of the participants were psychiatrist referrals, and 83 were followed up for at-least 1 year (mean follow-up=2.4 years). Fourteen developed psychosis and the estimated (by Kaplan-Meier) cumulative transition rate was 11.1% at 12, 15.4% at 24, and 17.5% at 30 months. At the end-point, about 30% of the 83 followed-up participants including 11 converters received antipsychotic medication. Compared to non-converters, converters showed more severe attenuated psychotic symptoms, including ego-boundary disturbance, formal thought disorder, and emotional disturbance. CONCLUSIONS The present study replicated previous major Western longitudinal studies, in terms of clinical characteristics, psychosis transition rate, and antipsychotic prescription rate. Our results emphasize the importance of phenomenological assessment of ARMS and intensive care in a clinical setting.

Application of the Comprehensive Assessment of At‐Risk Mental States (CAARMS) to the Japanese population: reliability and validity of the Japanese version of the CAARMS

Aim: The putative prodromal state of schizophrenia has been conceptualized as an at‐risk mental state (ARMS), which is identified on the basis of ultra‐high‐risk (UHR) criteria, and the Comprehensive Assessment of At‐Risk Mental States (CAARMS) has been developed as a specific instrument. However, the generalizability of CAARMS and the concept of ARMS have not been established. In this study, we tested the reliability and validity of the Japanese version of CAARMS (CAARMS‐J).

Relationship between cognitive insight and attenuated delusional symptoms in individuals with at-risk mental state

Cognitive insight, defined as the ability to evaluate and correct one׳s own distorted beliefs and misinterpretations, is hypothesized to contribute to the development of psychotic symptoms. We investigated cognitive insight in individuals with at-risk mental state (ARMS), which is associated with a clinically high risk of psychosis. Sixty individuals with ARMS were compared with 200 healthy controls in terms of cognitive insight measured using the Beck Cognitive Insight Scale. We also investigated the relationship between cognitive insight and attenuated delusional symptoms. In addition, we examined differences in the cognitive insight of individuals with ARMS with or without near-threshold delusional symptoms and differences in the cognitive insight of individuals with ARMS with or without later transition to psychosis. The results showed that individuals with ARMS exhibited higher self-certainty than healthy controls, indicating impairments in cognitive insight in the former. More importantly, our results revealed that self-certainty was correlated with attenuated delusional symptoms and that individuals with ARMS who had near threshold delusional symptoms had higher self-certainty. These findings indicate that overconfidence in one׳s own beliefs or judgments might be related to the formation and maintenance of attenuated delusions in individuals with ARMS.

Emotional processing during speech communication and positive symptoms in schizophrenia.

The recognition of emotion is often impaired in patients with schizophrenia. The relationship of this deficit with symptoms of psychosis remains unclear. In the current study, we investigated the relationship between emotional processing and positive psychotic symptoms in schizophrenia.

No regional gray matter volume reduction observed in young Japanese people at ultra-high risk for psychosis: A voxel-based morphometry study

OBJECTIVES Structural brain magnetic resonance imaging studies of individuals at ultra-high risk (UHR) for psychosis have shown subtle but widespread reductions in baseline gray matter volume (GMV) in the frontal, temporal, and limbic regions compared with healthy controls (HC). These regions coincide with regions of reduced GMV in patients with established psychosis and have led to the consideration of structural changes in UHR as a potential biomarker for future transition to psychosis. However, most studies have been from Europe, North America, and Australia, with few reports from other regions, and two recent studies from Asian countries have failed to detect regional GMV reduction in UHR, suggesting the need for further analysis of an Asian sample. In this study, we investigated GMV reduction in Japanese UHR subjects. RESULTS The study used voxel-based morphometry to compare magnetic resonance imaging brain scans between 45 UHR individuals recruited by a specialist and 33 HCs. This showed no significant GMV reduction in the UHR group compared with the healthy control group. This negative result may be attributable to characteristics of Asian samples, such as a low prevalence of illicit drug use, or to the heterogeneous nature of UHR subjects.