Prolonged untreated illness duration from prodromal onset predicts outcome in first episode psychoses

Several, although not all, studies suggest that prolonged duration of untreated illness (DUI) predicts poor outcome in psychotic disorders such as schizophrenia. It is unclear whether this association can be explained by factors such as baseline deficits or poor premorbid adjustment. First episode psychotic patients were evaluated at 1 and 2 years following baseline evaluations. Predictive measures showing significant correlations with outcome were entered in multiple regression analyses with Strauss-Carpenter scale (SC) and Global Assessment of Functioning scale (GAF) outcome scores as dependent variables. Illness duration computed from the onset of the prodrome (DUI-pro), used both as a dichotomous and as a continuous measure, highly significantly predicted both GAF and SC scores at 2 years. On the other hand, baseline functioning significantly predicted the 1-year but not the 2-year outcome. When Premorbid Adjustment Scale (PAS) scores were additionally entered into the analyses in a smaller subset, the relation between DUI-pro and the 2-year outcome scores remained significant. Significant associations were also seen between outcome and baseline neuropsychological deficits involving attention and memory. Further research is needed to examine whether prolonged untreated illness is simply associated with poor outcome or plays a causal role in relation to outcome. The latter, if true, would strongly support therapeutic intervention efforts in the prodromal and early psychotic phases of schizophrenia.