The potency of cannabis is increasing
The tetrahydrocannabinol (THC) content of cannabis has roughly quintupled in the past 2 decades, from around 4% in the 2000s to more than 20% in most legal dried cannabis in Canada by 2023. 

High-potency and regular cannabis use are associated with elevated risk of psychosis
The lifetime occurrence of cannabis-induced psychosis symptoms is estimated to be 0.47% among people who use cannabis.2 The risk of cannabis-induced psychosis is elevated among those using high-potency THC (a product with > 10% THC) and those who use cannabis frequently, are younger, or are male. Evidence also suggests that a history of a mental disorder (e.g., bipolar disorder, depression, anxiety) increases the risk of psychosis. More than half of patients with cannabis-associated psychosis recover within 24 hours, but those with prolonged symptoms (> 1 wk) or a history of psychosis have hospitalization rates ranging from 54% to 76%...