To evaluate the clinical and functional effects of cannabis abuse in patients at First Episode Psychosis (FEP) referring to Community Mental Health Centre (CMHC) “Bologna Ovest” and in patients admitted with a diagnosis of psychosis at the Modena Emergency Psychiatry Ward (EPW).

All FEP patients, aged 18-35, referring to CMCH “Bologna Ovest” in a 6-years period were evaluated and followed-up at 3 and 12 months. Of the 1559 psychiatric admissions at the Modena EPW in a 3-year period, those with a positive history for substance abuse were selected.

Among the 88 Bologna Ovest FEPs, 32% were cannabis abusers (FEP-c). In Bologna, FEP-c were more frequently natives (23.39% vs 31.13%; c sq=5.1; p=0.02) single (26.38% vs 0,0% c sq=7.3, p=0.007) and unemployed (13.50% vs 18.32%, c sq=2.4, p=0.1). Non FEP-c did not use any other drug (0.0% vs 26.1%, c sq=77.5; p< 0.001). A trend towards higher prevalence of hospital admission at follow-up was found for FEP-c (4.20% vs 2.4%, c sq=3.8, p=0.07). 22.0% of patients admitted at the Modena EPW had a positive history for substance abuse: of these, 7% were diagnosed with paranoid schizophrenia, which significantly correlated with the use of cannabinoids (alone or in association).

Our results enlighten that cannabis use is frequent among psychotic patients admitted to hospital and worsens clinical course of FEP patients, consistently with previous evidence (Hambrecht & Hafner, 1996; Hafner et al., 2004).