Enhancing recovery in early schizophrenia–a controlled clinical trial investigating cannabidiol Cr vs. placebo as an add-on to antipsychotic treatment

Current antipsychotic treatments of schizophrenia are only partially effective, and their use is often associated with serious side effects. Cannabidiol is a natural counterpart of the psychoactive component of marijuana, delta-9-tetrahydrocannabinol and has no psychotomimetic or addictive properties. In a controlled clinical trial of cannabidiol versus amisulpride in acute paranoid schizophrenia we showed a statistically signifi cant clinical improvement in all symptoms clusters of schizophrenia compared to baseline with either treatment. Cannabidiol displayed a signifi cantly superior side-effect profi le in particular regarding prolactin elevation, extrapyramidal symptoms and weight gain. The favorable side-effect profi le and potentially novel mechanism of action identify this molecule as a potential antipsychotic. However, long-term safety and effi cacy data is still lacking. This study in 180 remitted schizophrenia patients is to evaluate the effi - cacy and safety of the novel compound cannabidiol in the maintenance treatment of schizophrenia in comparison to placebo as an add-on to an established treatment with either olanzapine or amisulpride, in a 12 months, double-blind, parallel-group, randomized, placebo-controlled clinical trial. Thereby, relevant data on cannabidiol ’ s antipsychotic potential will be gained.