Some people think that there is a critical period - just after people become ill with psychosis - in which the potential exists to intervene and improve the long-term course of the illness. However, there is no evidence that indicates how long early interventions need to be active to prevent a relapse or how long the effects last. A Danish study of 547 patients with first-episode psychosis compared a two-year, intensive, early-intervention treatment made up of assertive community treatment, family involvement and social-skills training to standard treatment. There was an improvement in the early-intervention group after two years but after five years there was no difference between the two group as far as symptoms were concerned. But fewer of the early-intervention group were living in sheltered housing and they had had fewer days in hospital over the 5-year period.
Bertelsen, Mette ... [et al] - Five-year follow-up of a randomized multicenter trial of intensive early intervention vs. standard treatment for patients with a first episode of psychotic illness Archives of General Psychiatry July 2008, 65(7), 762-771