High potency pot 'strongly linked' to psychosis: study (Medical Xpress)

High potency cannabis, especially when used daily, is "strongly linked" to the risk of developing psychotic disorders such as schizophrenia and paranoia, scientists said Wednesday. In Amsterdam and London—where high-THC marijuana has long been the rule rather than the exception—50 and 30 percent of new psychosis cases, respectively, were associated with potent forms of the drug.
https://medicalxpress.com/news/2019-03-high-potency-pot-strongly-linked.html, 20.3.2019