Untreated illness and outcome of psychosis.

BACKGROUND There has been controversy as to whether early intervention in psychosis can improve the outcome of the disorder. AIMS To establish if there is an association between duration of untreated psychosis and the 4-year outcome of persons with a first episode of psychosis. METHOD Prospective naturalistic follow-up study of the outcome of consecutive first presentations with DSM-IV psychosis attending a community-based psychiatric service. RESULTS A longer duration of untreated psychosis was associated with a significantly poorer functional and symptomatic outcome 4 years later. For schizophrenia and schizophreniform disorder, each increment in duration of untreated psychosis was associated with a 7.8 point decrease in global functioning and an increase in positive symptoms scores by 1.9 points. CONCLUSIONS This study extends the findings of short-term follow-up studies by confirming an association between duration of untreated psychosis and 'mid-term' outcome.