Mental illness and cannabis use

Cannabis use may increase the risk of developing schizophrenia, particularly in people who start at a young age or have heavy use. Cannabis can contribute to relapse of mental illness in people with schizophrenia, bipolar disorder or depressionLowe, 2019. Many patients with mental illness or social difficulties use considerable quantities of cannabis. Charting episodes of cannabis use and relapse may be a motivational tool, showing how use leads to hospitalisation and other adverse outcomes.

Cannabis withdrawal can unmask undiagnosed psychiatric illness, which can present as a first episode of psychosis, trigger a re-emergence or precipitate deterioration of symptomsNSW Health, 2008. Consider the need to admit a patient to manage withdrawal if they are at risk of these events.