Cannabinoids 2008;3(4):11-14 (9 November 2008)

Mini-review

Cannabinoids and schizophrenia: where is the link?

Kirsten Müller-Vahl

Clinic of Psychiatry, Socialpsychiatry & Psychotherapy, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany, mueller-vahl.kirsten@mh-hannover.de

Highlighting the association between schizophrenia and cannabis sativa and the endogenous can-nabinoid receptor system, respectively, two opposite aspects are of major relevance. On the one hand, there is substantial evidence that cannabis has to be classified as an independent risk factor for psychosis that may lead to a worse outcome of the disease. This risk seems to be increased in genetically predisposed people and may depend on the amount of cannabis used. On the other hand, there are several lines of evidence suggesting that, at least in a subgroup of patients, altera-tions in the endocannabinoid system may contribute to the pathogenesis of schizophrenia, e.g., in-creased density of cannabinoid receptor type 1 (CB1) binding and increased levels of cerebrospinal fluid (CSF) anandamide. Accordingly, beside the „dopamine hypothesis“ of schizophrenia a „can-nabinoid hypothesis“ has been suggested. Interestingly, there is a complex interaction between the dopaminergic and the cannabinoid receptor system. Thus, agents that interact with the cannabinoid receptor system such as the non-psychoactive cannabidiol (CBD) have been suggested for the treatment of psychosis.

Keywords
Cannabis, THC, tetrahydrocannabinol, schizophrenia, psychosis

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