Substance Misuse To Psychosis for Stimulants

Substance Misuse To Psychosis for Stimulants (SToP-S)--An Early Assertive Pharmacotherapy Intervention Study

In Hong Kong, less than 5% of stimulants abusers were reported to misuse these substances via injection. Also, it is well known that patients with co-morbid substance abuse/dependence and psychosis or schizophrenia-related disorders are prone to earlier treatment discontinuation and high oral medication non-adherence, resulting in poorer overall outcomes. With the recent availabilities of the 4-weekly long-acting injectable form of aripiprazole, and the 4-weekly and the 3-monthly long-acting injectable form of paliperidone palmitate, on the background of the surging phenomenon of stimulant misuses in Hong Kong, it is a timely opportunity to conduct an early pharmacotherapy intervention study to offer an evidence-based strategy aiming to stop individuals with substance use disorders with psychosis to develop into a more chronic disabling dependence or co-morbid state.

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