Substance Misuse To Psychosis for Ketamine (SToP-K)

Study Overview
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Brief Summary
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Evidence suggests that repeated or chronic ketamine use, as compared to acute ketamine users, posed a higher clinical risk of developing psychotic disorders, potentially related to the underlying chronic N-methyl-D-aspartate receptor (NMDAR) dysfunction, and a higher risk of suffering from schizophrenia particularly in those genetically susceptible, or genetically predisposed ketamine abusers. With ketamine infusion rises as a emerging hope as an acute treatment for depression and suicidality under the shadow of unknown longer term psychotomimetic effects peculiarly amongst repeated or chronic use, the current case-control study aims to investigate: a) if repeated or chronic ketamine use is associated with an increased risk of psychosis by comparing those ketamine abusers with and without psychosis, and to those non-ketamine-using drug abusers with psychosis; and b) if genetic predisposition from single nucleotide polymorphisms are associated with risk of psychosis in ketamine abusers.

Official Title
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Substance Misuse To Psychosis for Ketamine (SToP-K) -Who is At Risk? A Case-Control Study in Ketamine and Non-Ketamine-Using Substance Abusers

Conditions
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Ketamine Abuse, Psychotic Disorders, Substance Use Disorders, Schizophrenia, Genetic Predisposition

Intervention / Treatment
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* Diagnostic Test: genome testing


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age: 12 - 65 years old Able to read and communicate in English and/or Chinese Able to give informed consent Self-reported to have psychoactive substance use continuously for ≥3 month At least one positive urine toxicology result showing the reported psychoactive substance being used Exclusion Criteria: Age <12 years old Unable to read English or Chinese Unable to give informed consent Had been diagnosed to have Intellectual Disabilities (DSM-5) or Mental Retardation (ICD-10, F70-73) Had been diagnosed to have primary psychosis prior to the use of any psychoactive substances, including alcohol Had been diagnosed to have bipolar and related disorder prior to the use of any psychoactive substances, including alcohol Had been diagnosed to have major depressive disorder with psychotic features prior to the use of any psychoactive substances, including alcohol Had been diagnosed to have psychotic disorder due to another medical condition (DMS-5) Self-reported to have abstained from any psychoactive substance use continuously for ≥12 months AND with negative urine toxicology result at the time of recruitment/ intake at the psychiatric services as recorded on case notes

Ages Eligible for Study
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Minimum Age: 12 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Case<br>Ketamine user with psychotic disorders | Diagnostic Test: genome testing<br>* blood sampling via venipuncture<br>|
| Control Group 1<br>Ketamine user without psychotic disorders | Diagnostic Test: genome testing<br>* blood sampling via venipuncture<br>|
| Control Group 2<br>Non-ketamine-using drug user with psychotic disorders | Diagnostic Test: genome testing<br>* blood sampling via venipuncture<br>|
| Control Group 3<br>Non-ketamine-using drug user without psychotic disorders ( identified from register-based medical record system) | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| relative risk of ketamine users compared to non-ketamine using drug user to develop psychosis | relative risk of ketamine users compared to non-ketamine using drug user to develop psychosis | During the 2 year study period | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gene association to development of psychcosis | The single nucleotide polymorphism of 4 genes associated with N-methyl-D-aspartate and dopamine receptors being associated with the development of psychosis in ketamine abuser | During the 2 year study period |