Medium-term outcomes and risk factors for methamphetamine-induced psychotic disorders: a prospective cohort study among people who inject drugs in Haiphong, Vietnam.

Background: Methamphetamine (MA) use is growing in every part of the globe. Increased risk of transient and persistent psychotic disorder among people who use MA is already documented but little data exist on medium-term outcome for MA-induced psychotic disorders. Our objective was to describe medium-term psychiatric outcomes in a cohort of people who use MA, and examine factors associated with MA-induced psychotic disorder.

Methods: Using four respondent driven sampling surveys (RDS) conducted among people who inject drugs in Haiphong Vietnam, we constituted a cohort of people with a current regular MA use who are free from psychotic symptoms at baseline. Visits occurred biannually. MA use was assessed by self-report and urine tests. Psychotic symptoms were screened using a short questionnaire adapted from the Mini International Neuropsychiatric Interview (5.0.0). Trained interviewers administered structured interviews covering socio-demographic characteristics, drug use, quality of life and other health-related outcomes.

Results: The four large RDS surveys conducted between 2016 and 2019 (Ns approximately 1500 each) in the broader DRIVE project enabled us to include in a prospective cohort study more than 150 participants with current regular MA use and free from psychotic symptoms at baseline. Follow-up ranged from six to thirty-six months. The analyses are ongoing and the consolidated results are expected in April 2022.

Perspectives: Understanding MA-induced psychotic disorders and identifying their risk factors will allow to improve the care of people who use MA and to offer an appropriate global psychiatric intervention.