Substance Misuse To Psychosis for Stimulants

Inclusion Criteria: • Stimulant use disorder with psychosis or positive stimulant urine test results twice in a month with psychosis Exclusion Criteria: * Age \<16 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 Schizophrenia * Had been diagnosed to have other substance-induced psychotic or mood disorder, including alcohol * Had been diagnosed to have bipolar disorder viii. Had been diagnosed to have major depressive disorder with psychotic features * Had been taking any maintenance dose of oral antipsychotics continuously ≥12 weeks AND with psychotic symptoms in remission * Had been receiving any maintenance dose of long-acting injectable (LAI/depot) antipsychotics continuously ≥4 month AND with psychotic symptoms in remission * Had known hypersensitivity to risperidone (oral or LAI), paliperidone (oral or LAI), or aripiprazole (oral or LAI) * Had known history of tardive dyskinesia * Had known history of neuroleptic malignant syndrome * Pregnant * Mother currently breast-feeding * Had history of prolonged corrected QT interval (QTc) ≥500ms and/or known unstable or untreated cardiac disorder * Had mild to severe renal impairment with Glomerular Filtration Rate \<80 mililitre /min