Duration of untreated illness (DUI) and schizophrenia sub-types : a collaborative study between the universities of Milan and Moscow

Background: Several studies show an association between a long duration of untreated illness (DUI) and poor outcome in schizophrenic patients. DUI, in turn, may be influenced by different variables including specific illness-related factors as well as access to local psychiatric services. Aims: The purposes of the present study were to detect differences in terms of DUI among schizophrenics coming from different geographic areas and to evaluate differences in DUI across diagnostic sub-types. Method: One hundred and twenty-five (125) schizophrenic patients of the Psychiatric Clinic of Milan (n = 51) and Moscow (n = 74) were enrolled. SCID-I was administered to all patients and information about DUI was obtained by consulting clinical charts and health system databases, and by means of clinical interviews with patients and their relatives. DUI was defined as the time between the onset of illness and the administration of the first antipsychotic drug. One-way analyses of variance (ANOVAs) were performed to find eventual differences in terms of DUI across diagnostic sub-types. Results: Italian patients showed a longer DUI (M = 4.14 years, SD = 4.95) than Russians (M = 1.16 years, SD = 1.43) (F = 24.03, p < .001). DUI was found to be longer in paranoid schizophrenics (M = 3.47 years, SD = 4.19) compared to catatonic patients (M = 0.96 years, SD = 0.94) (F = 3.56, p = .016). Conclusions: The results of the present study suggest that the different schizophrenic sub-types may differ in terms of DUI, likely due to different clinical severity and social functioning. Studies with larger samples are needed to confirm the data of the present study.