Duration of untreated psychosis an indicator of illness stage, not a predictor of course
Duration of untreated psychosis (DUP) is associated with psychosocial function, but it appears to be only an “artifact” of early detection, suggests a recent study. Such association creates the impression that early intervention can lead to improved outcomes.
A long DUP had been thought to predict illness severity and worse treatment outcomes, but the mechanisms behind it were unclear. It was thought that lengthy untreated psychosis was toxic or that it represented a more severe form of schizophrenia. On the other hand, others thought that the association was an artifact of lead-time bias, according to the authors.
A longitudinal study of schizophrenia with 2,137 observations spanning from childhood to 20 years after first admission was conducted to test these hypotheses. Data were obtained from the Suffolk County Mental Health Project, which included 287 individuals with schizophrenia or schizoaffective disorder.
DUP was defined as days from first psychotic symptom to first psychiatric hospitalization. The Premorbid Adjustment Scale and the Global Assessment of Functioning Scale were used to evaluate psychosocial function. Multilevel spline regression models adjusted for gender, occupational status, race and antipsychotic medication was used to estimate the psychosocial function trajectories.
Declines in psychosocial function occurred similarly in both long- and short-DUP patients. However, these declines happened at various times relative to first admission. Long-DUP patients experienced most of these declines before their first admission, while short-DUP patients experienced declines after.
Furthermore, DUP was not able to predict the course of illness when psychosocial function was analysed relative to psychosis onset.
“In other words, DUP may be better understood as an indicator of illness stage than a predictor of course,” the authors said.