The effects of cannabis use on the brain, mind, and body have been studied for decades. The developing brain, particularly the adolescent and young adult brain, undergoes critical development that makes it especially susceptible to the effects of cannabis use. Among the adverse effects of cannabis use in adolescence and young adulthood, psychosis and psychotic disorders (e.g., schizophrenia) have been examined. The association of cannabis use with schizophrenia was first elucidated in a Swedish study of army conscripts. Specifically, conscripts reported their cannabis use exposure and were followed longitudinally to assess the emergence of schizophrenia. The authors found that those who reported persistent cannabis use during adolescence had higher rates of schizophrenia diagnoses.

Notwithstanding this correlation, a causal relationship has not yet been established between adolescent cannabis use and schizophrenia. Some believe that in the premorbid phase of schizophrenia, one may self-medicate with cannabis, accounting for the correlational relationship. However, this evidence is not supported by the literature. Prolonged, frequent use of exogenous cannabinoids such as phytocannabinoids and synthetic cannabinoids perturb the endocannabinoid system, particularly during the critical period of adolescence. Many researchers believe this perturbation contributes to psychosis and the pathogenesis of schizophrenia. In this review, I demonstrate how cannabis may contribute to symptoms of psychosis and associated with diagnoses of schizophrenia. PubMed and Google Scholar were used with the following search terms "cannabis-induced psychosis" AND schizophrenia. These search terms were narrowed by clicking on "adolescent." Also, based on the diathesis-stress model, I explored how cannabis may be one of many neurological insults leading to the onset of schizophrenia. In the future, research should be conducted focusing on other drugs as a trigger for schizophrenia.