Schizophrenia is the psychotic disorder that currently has the worst prognosis, as it causes deterioration in almost all the psychological functions of the individual and hinders their social, academic and work adaptation. A term widely described as a prognostic factor for schizophrenia is the duration of untreated psychosis (DUP), which refers to the time elapsed between the appearance of psychotic symptoms and the moment when treatment begins. The objective of this study is to evaluate the duration of untreated psychosis greater than three months as a factor of poor prognosis of patients with schizophrenia, compared with patients with duration of untreated psychosis less than three months, at Nuestra Señora de la Paz Hospital between June 2021 and May 2022. An analytical retrospective cohort study was conducted in which the two groups mentioned above were compared, considering the length of hospitalization, number of re-admissions, the global functioning evaluated with the GAF and WHODAS, and cognition evaluated with the MoCA Test, as outcomes to be evaluated in both groups. Results: we evaluated 69 subjects with first psychotic episode (FPE) of whom, after the semi-structured SCID-IV diagnostic interview, 43 subjects were identified with schizophrenia. We found statistically significant differences between the groups of patients with DUP <3 months and DUP >3 months, for the outcomes of functioning/degree of disability (p= 0.001 y p=0.001 respectively), and cognitive performance (p= 0.001), while no statistically significant differences were found in the outcomes of time of hospitalization (0.445) and relapses in patients with FPE. Conclusions: patients with DUP >3 months have a poorer prognosis in terms of global functioning, degree of disability and cognitive functioning, compared to patients with DUP <3 months
