Researching the impact of Cannabis use on the behavior of patients with schizophrenia is a relatively recent phenomenon. The author's work focuses on analyzing the behavioral experiences of schizophrenic patients who use Cannabis, which is often aggressive and violent. The comorbidity of Cannabis use and mental disorders was examined through the experiences of patients with schizophrenia, based in the East of England. The empirical work involved examining the patterns of comorbidity through the use of the most often used psychoactive substances among young adults in the East of England e.g. alcohol, tobacco, and Cannabis use. Twenty-five schizophrenic patients were recruited and interviewed for the research, which facilitated the opportunity to learn the patients’ perception of their behavior and the adverse impact of using Cannabis concurrently with their prescription medication.