Currently, the pharmacotherapy of schizophrenia is still associated with significant side effects and high rates of treatment resistance, causing a great deal of suffering to patients and their caregivers. Developing safe interventions able to prevent the emergence of full-blown psychosis would therefore represent a major advance. Cannabidiol (CBD) is a non-psychotomimetic compound of Cannabis sativa that presents antipsychotic properties in animal models and humans (Zuardi et al., 2012). However, despite the growing evidence of CBD’s neuroprotective effects (Zuardi, 2008) and therapeutic application in schizophrenia, so far no study has addressed its potential as a preventive intervention.