A new study from Ontario has found that the number of people diagnosed with schizophrenia after receiving care for cannabis use disorders (CUDs) has increased significantly since cannabis legalization. The study, which analyzed data from 2006 to 2022, shows a tripling of schizophrenia cases associated with CUDs over the past 17 years.
Before legalization, only about four per cent of new cases of schizophrenia were linked to CUDs. However, after cannabis was legalized, this proportion rose to 10 per cent. The study found that hospital care for CUDs increased by 270 per cent, from one in every 1,000 people before legalization to four and a half in every 1,000 after.
The researchers note that the study has limitations, including a lack of data on individual-level factors such as income and education. However, they emphasize the need for targeted prevention strategies, particularly for younger populations who appear at greatest risk. The study highlights the urgent need to address the growing public health challenge posed by high-potency cannabis and rising regular use.
The authors also caution that while heavy cannabis use may worsen symptoms and prognosis for those with schizophrenia, it does not necessarily cause the condition. Ongoing research is needed to evaluate long-term trends in psychotic disorders associated with changes in cannabis policy, particularly the commercialization of the legal market.
Source: https://www.ctvnews.ca/toronto/article/new-schizophrenia-cases-linked-to-cannabis-use-disorders-nearly-tripled-over-17-year-period-ontario-study