Medication adherence and cannabis use among schizophrenic patients

Introduction Substance use is usually associated with poorer psychiatric medication adherence among schizophrenic patients. Previous findings remain unclear about the relationship between cannabis use and poor medication adherence. Identifying predictor factors of medication adherence among these patients is very important because it's associated with relapse and re-hospitalization. Objective Determining whether cannabis use is a risk factor for compliance to medication in a population of schizophrenic patients. Method Schizophrenic inpatients were assessed by Medication Adherence Rating Scale (MARS). Socio-demographic, clinical data, and urine drug screens were collected just after their admission. Results A sample of 403 inpatients with schizophrenia diagnosed with Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) criteria (mean age=33, 35±9, 16), predominantly man (90%), paranoid (62%) and 89% of them received classical antipsychotics. A total of ( n =25; 6, 2%) inpatients were adherent, among this group, 19 patients (76%) were tested negative for cannabis use, and the rest of them ( n =6; 24%) were tested positive. These results show a high significant correlation between cannabis use and medication adherence ( P =0.009). Besides, medication adherence is strongly associated with a high socioeconomic status ( P =0.005). Conclusion Cannabis use has a major effect on the non-adherence to medication treatment for schizophrenia. These results could be more effective if it addresses issues of cannabis use with patients throughout the early years of treatment.