06 June 2023

According to Professor Michael Davidson, Chair of Psychiatry at the University of Nicosia Medical School, and one of the authors of a recent study published in the prestigious journal Schizophrenia Bulletin titled ‘Cannabis Use and Symptomatic Relapse in First Episode Schizophrenia: Trigger or Consequence? Data From the OPTIMISE Study’, schizophrenia is a disease that affects approximately 1% of the general population. It presents as intermittent episodes of psychosis, and in about two-thirds of patients, symptoms remit or improve with the administration of antipsychotic drugs. However, psychotic symptoms tend to re-emerge either because patients stop taking antipsychotic medication or despite continuous treatment with medication.

To explore ways of reducing the risk of psychosis re-emergence in patients in remission, the European Community funded a large study involving 446 patients diagnosed with a first episode of schizophrenia (NCT01248195, ww.clinicaltrials.gov). The results of this study revealed that cannabis use increases the rate of relapse in both treatment-compliant and non-compliant individuals who are in remission from their first episode of schizophrenia.

What’s particularly noteworthy is the temporal relationship observed between cannabis use and relapse. According to Professor Michael Davidson, cannabis use preceded later relapse, non-compliance, and a decrease in social functioning, rather than patients relapsing and then turning to cannabis as a result.

These findings shed important light on the impact of cannabis use on patients in remission from schizophrenia and emphasize the need for further research and awareness regarding the potential risks associated with cannabis in this population.