The Predictive Role of Self-representation in Transition of Individuals at Clinical High Risk for Psychosis

Study Overview
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Brief Summary
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Schizophrenia is one of the most consumptive diseases, which brings great loss to patients and their families, and even to the society. Clinical High Risk for Psychosis (CHR) is a concept put forward on the basis of the prodromal stage of schizophrenia. Over the past 20 years, the identification and intervention of CHR has become the focus of psychiatric research, with the primary goal of early identification of biomarkers of susceptibility to schizophrenia and the development of individualized interventions to prevent or delay progression. Longitudinal studies have shown that CHR converted to schizophrenia mainly within two years, with a risk of about 30 percent. Self-disorder is one of the core characteristics of schizophrenia. The two most basic experiences of self-representation are sense of ownership and sense of agency. Sense of ownership refers to the sense that I perceives my body, while sense of agency refers to the sense that I experiences my actions and their consequences are initiated by me. Some studies have shown that patients with schizophrenia show defects in the sense of ownership and agency. The most commonly used paradigm for observing sense of ownership and sense of agency is the rubber hand illusion (RHI) or the virtual hand illusion (VHI). In this study, the VHI experimental paradigm will be used to detect the self-representation of the individuals at high risk for psychosis, and the clinical outcome will be observed for one year.The hypothesis is that the subjects who exhibit abnormal illusion experience in VHI experiment are more likely to transition into psychotic disorders.

Detailed Description
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This study is conducted according to the tenets of the Declaration of Helsinki. All participants are recruited at the Shanghai Mental Health Center (SMHC) or its affiliate, the Shanghai Psychotherapy and Psychological Counseling Center (SPCC) with written informed consent, approved by the Research Ethics Committee of SMHC. For those younger than 18 years, both the adolescents and their next of kin or legal guardians are provided informed consents. The outpatients are recommended by doctors to participate in our CHR screening. After being screened and interviewed, those who meet the inclusion criteria are informed and signed written informed consent. Once the subjects are recruited, clinical evaluation, VHI and MCCB test will be conducted. In addition, CHR individuals will be followed up at one-year node.

Official Title
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The Predictive Role of Self Representation in Transition of Individuals at Clinical High Risk for Psychosis -- a Study on the Clinical Application of Virtual Hand Illusion

Conditions
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Clinical High Risk for Psychosis

Intervention / Treatment
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* Diagnostic Test: Virtual hand illusion (VHI)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: For CHR individuals, meet the criteria of psychosis-risk syndromes after rating by structured interview for psychosis high risk syndrome. For FES patients, meet diagnostic criteria for schizophrenia in the DSM-IV. For HC individuals, gender composition, age range, educational level are matched with CHR individuals. Understand and sign written informed consent. Exclusion Criteria: For CHR individuals, exclude individuals with other axis I or II mental disorders, which can explain the abnormal experience. For CHR and FES patients, exclude those patients taking antipsychotics for more than two weeks. For HC individuals, exclude those with family history of mental disorders With a history of substance dependence. Use of medications that may affect mental and cognitive functions. With central nervous system disorder, that cuase symptoms or interfere with judgment. Traumatic brain injury score is 7 or more. With serious or unstable physical diseases. With perceptual developmental disorders. IQ<70.

Ages Eligible for Study
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Minimum Age: 11 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Clinical high risk for psychosis (CHR)<br>No intervention. Just use virtual hand illusion (VHI) paradigm to observe the outcome of individuals with CHR at one-year follow-up node and analyze the predictive role of self-representation in transition into psychosis. | Diagnostic Test: Virtual hand illusion (VHI)<br>* Using VHI, the two basic self-representation of sense of ownership and sense of agency of the subjects will be observed.<br>|
| First episode of schizophrenia (FES)<br>In contrast to FES, it is anticipated to observe CHR individuals with similar behavioral performance to FES may presented higher risk of transition. | Diagnostic Test: Virtual hand illusion (VHI)<br>* Using VHI, the two basic self-representation of sense of ownership and sense of agency of the subjects will be observed.<br>|
| Healthy control (HC)<br>In contrast to HC, it is anticipated to observe CHR individuals with similar behavioral performance to HC may presented lower risk of transition. | Diagnostic Test: Virtual hand illusion (VHI)<br>* Using VHI, the two basic self-representation of sense of ownership and sense of agency of the subjects will be observed.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Behavioral indicators | To compare the behavioral performance in VHI experimental paradigm among the three groups of CHR, FES, and HC | Baseline | 
| Predictive indicators | To analyze the predictive role of self-representation in transition of CHR into psychosis | One-year follow-up node | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Resting-state brain functional connectivity (FC) | To observe the relationship of the behavioral performance in VHI experimental paradigm with the Resting-state brain functional connectivity | Baseline | 
| Event-related potential technique | To observe the relationship of the behavioral performance in VHI experimental paradigm with the error-related negativity | Baseline | 
| Neurocognitive function | To observe the relationship of the behavioral performance in VHI experimental paradigm with the neurocognitive functions | Baseline | 
| Other predictive indicators | To analyze the predictive role of FC and neurocognitive functions related to self-representation in transition of CHR into psychosis | One-year follow-up node | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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sense of ownership, sense of agency, virtual hand illusion