UNSW Study Finds Cannabis Brings Psychosis Onset Forward 6.3 Years After Age 30
Updated
Updated · australianpharmacist.com.au · Aug 19
UNSW Study Finds Cannabis Brings Psychosis Onset Forward 6.3 Years After Age 30
3 articles · Updated · australianpharmacist.com.au · Aug 19
Summary
Cannabis users who later developed psychosis at age 30 or older did so 6.3 years earlier on average than non-users, versus 1.6 years earlier in the early 20s and 4.43 years earlier in the late 20s.
UNSW researchers said the age pattern challenges the belief that cannabis becomes relatively safe after 25, pointing instead to a cumulative harm effect that may intensify with longer exposure.
The team warned medicinal cannabis may be reinforcing a false sense of safety, even though a recent review found no evidence it works for anxiety, depression or PTSD and TGA guidance says THC products are generally unsuitable for patients with psychotic or active mood and anxiety disorders.
Prescribing has surged from about 18,000 patients in 2019 to more than 1 million by early 2024, and researchers said pharmacists should use dispensing encounters to screen for family or personal psychosis risk, especially in closed-loop prescribing models.