[Clinical characteristics of cannabis-induced schizophrenia spectrum disorder]

Marijuana (cannabis) is the most commonly abused drug by adolescents and young adults and also by people with schizophrenia or other psychotic disorders. An increasing number of studies suggest that regular cannabis users can show psychotic episodes similar to schizophrenic disorders but it still unclear if cannabis induced psychotic disorder is a distinct entity requiring special therapy or regular cannabis use consequently leads to schizophrenia. Therefore, we retrospectively compared psychotic patients with and without cannabis use by clinical profile. Clinical data of 85 patients with schizophrenia spectrum disorder were analyzed retrospectively. Cannabis use was not reported by 43 persons (Cnbs0 subgroup) and 42 patients used regularly cannabis during at least 1 year (Cnbs1 subgroup). Clinical data were collected from electronic medical documentation of patients concerning anamnesis, family history, socio-demographic condition, symptoms and psychiatric state, acute and long-term therapies. Men were over-represented in the cannabis abuser group while mean age was lower among them compared to the Cnbs0 subgroup. Prevalence of suicidal attempts was increased in men without cannabis use. Patients without cannabis use spent more time in hospital and smoking was more frequent among them. Positive and negative symptoms and family history did not differ significantly between the two subgroups. Dosage, intensity and length of pharmacotherapy was different between the two subgroups. These results revealed that certain clinical aspects were different in case of cannabis-related schizophrenia spectrum disorder compared to schizophrenia.