Does substance use disorder affect clinical expression in first-hospitalization patients with schizophrenia? Analysis of a prospective cohort.

Although several papers reported a wide range of negative outcomes among patients with both schizophrenia and Substance Use Disorder (SUD), only a few studies evaluated the impact of SUD on psychopathology and thus on the length of first-hospitalization. The aim of the present study was to compare clinical expression of first-episode of schizophrenia between inpatients with and without SUD, giving close attention to the length of stay. One hundred and thirty inpatients at first-episode of schizophrenia were assigned to either SUD or not SUD group depending on SUD diagnosis and were assessed through BPRS at admission, during hospitalization and at discharge. Cross-sectional and longitudinal statistical analysis were performed to investigate differences between groups and also a linear regression was used to evaluate relationship between length of stay and BPRS scores. SUD group showed more disorganization at admission, less marked improvement of symptoms (disorganization, thought disturbance, anergia), and longer hospital stay than not SUD group. Moreover BPRS total score during hospitalization was a significant positive predictor for length of stay. Taken together, these findings suggest that SUD patients have a more severe and drug-resistant expression of schizophrenia, hence, they need longer treatment to achieve the overall symptoms improvement required for discharge.