Cannabis consumption rarely triggers episodes of acute psychosis in those who do not have a pre-existing psychiatric disorder, according to the results of a meta-analysis published in the journal Nature: Mental Health. An international team of researchers from Switzerland and the United Kingdom reviewed the relationship between use and cannabis-associated psychotic symptoms (CAPS) in 162 studies involving over 210,000 cannabis consumers.
Researchers reported that the risk of psychosis “appears most amplified in vulnerable individuals” particularly those with “pre-existing mental health problems” such as bipolar disorder. By contrast, they acknowledged, “Neither young age of onset of cannabis use nor high-frequency use of cannabis or the preferred type of cannabis (high in THC, high in CBD) was associated with CAPS”. Overall, they estimated that 0.5% of those who consume cannabis may experience a psychotic episode during their lifetime. That percentage mirrors estimates published in a prior study involving 233,000 European consumers.
