Aim: To provide an overview of the currently understood structure and function of the endocannabinoid system and the putative relationships of endocannabinoid system dysfunction and schizophrenia. To delineate potential novel targets in the endocannabinoid system for therapeutic modulation.
Design: Narrative review of peer reviewed research articles and authorative texts.
Study (and authorative text) selection and analysis: Several databases including PubMed, Science Direct and University of Dundee library were systematically searched for studies addressing the issues of: (a) an association between cannabis and schizophrenia; (b) an association between any component of the endocannabinoid system and schizophrenia; and (c) possible interventions in schizophrenia by modulating the endocannabinoid system were included. Authorative texts were manually located and information selected according to the same criteria.
Results: This paper provides an overview of the currently known structure and function of the endocannabinoid system. Exogenously administered cannabinoids can produce a range of psychoactive effects including a psychosis with similar clinical features to acute schizophrenia. Additionally, cannabis may contribute to the development of schizophrenia in susceptible individuals. Changes are seen in the endocannabinoid system in schizophrenia and there are putative links between endocannabinoid system dysfunction and the disorder. Phytocannabinoids as well as commercially developed compounds acting on the endocannabinoid system have demonstrable antipsychotic effects.
Conclusions: This review highlights the putative links between endocannabinoid system dysfunction and schizophrenia. Traditional antipsychotic agents have demonstrable effectiveness in treating schizophrenia and were developed in response to the dopamine hypothesis of schizophrenia. However, there remains considerable scope for improvements to be made in the management of this challenging disorder. Aberrant functioning of the endocannabinoid system could represent an exciting therapeutic target for the development of novel effective agents.