Differences in frequency of daily cannabis use and in use of high-potency cannabis contributed to the striking variation in the incidence of psychotic disorder across the 11 studied sites. Given the increasing availability of high-potency cannabis, this has important implications for public health.

https://www.kcl.ac.uk/ioppn/news/records/2019/march/high-potency-cannabis-linked-to-higher-rates-of-psychosis

https://www.thelancet.com/journals/lanpsy/article/PIIS2215-0366(19)30048-3/fulltext

https://psiquiatria.com/adicciones/el-12-7-de-los-casos-de-psicosis-en-madrid-estan-relacionados-con-el-consumo-diario-de-cannabis-segun-un-gran-estudio/