ObjectiveThis study examined stimulant and medicinal cannabis prescribing in individuals before and after referral to an early psychosis (EP) service in Queensland, Australia.MethodsA retrospective review of 220 consecutive EP referrals (2019-2023) was conducted, extracting data on stimulant and medicinal cannabis prescriptions from clinical records. Longitudinal prescribing patterns were analysed, with descriptive comparisons of Δ9-tetrahydrocannabinol (THC) concentrations in medicinal cannabis prescriptions before and after the onset of psychosis.ResultsPrior to referral, 4.5% of patients were prescribed stimulants and 3.2% medicinal cannabis, with most having a history of substance use. After a psychotic episode, 3.2 % were prescribed stimulants and 6.8% were prescribed medicinal cannabis, with mean THC concentrations higher after the onset of a psychotic illness (31.4% vs 16.9%). Over 70% of those prescribed stimulants and 60% prescribed medicinal cannabis after experiencing a psychotic episode had further contact with mental health services due to concerns about a deterioration in mental state where these medications were thought to be a contributory factor.ConclusionsIt is of concern that THC concentrations were higher in prescriptions made post-EP discharge. Enhanced safeguards are required to mitigate risks and reliably identify patients where such prescription would be contraindicated.
Keywords: cannabis; early psychosis; psychosis; schizophrenia; stimulants.