Substance Misuse To Psychosis for Ketamine (SToP-K)

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