Longer Duration of Untreated Psychosis is associated with poorer outcomes for patients with Delusional Infestation

We examined the association between the duration of untreated psychosis (DUP) and outcome for patients with delusional infestation (DI). This multi-centre international study included consecutive 211 patients. Illness severity was evaluated at first presentation and outcome was measured with the Clinical Global Impression scale (CGI) at base line and follow-up. A regression analysis showed a clear clinical and statistically significant association between shorter duration of untreated psychosis and better outcome at follow up. Patients with a DUP of less than 1 year showed a CGI-S change from 5.37 to 2.07; those with a DUP of 1-5 years a change from 5.48 to 2.59, and those with a DUP of above 5 years a change from 5.59 to 3.37. This difference of 1.1 CGI points between the groups resembles a clinically relevant difference in patient outcome Our results suggest that longer duration of untreated psychosis in patients with DI is associated with significantly less favourable clinical outcomes.