Duration of untreated illness and outcome in schizophrenia: test of predictions in relation to relapse risk.

Background: The nature of the relationship between duration of the pre-diagnostic interval in schizophrenia and better outcomes remains unclear.

Aims: To re-examine data from one of the earliest studies suggesting an association between long pre-treatment interval and compromised outcome, assessing the relationship between symptomatic and social variables and increased relapse risk at 1 year.

Method: Symptomatic, social and demographic data from participants in the Northwick Park Study of First Episodes who completed 12-month follow-up (n = 101) were re-analysed in the context of duration of untreated illness (DUI).

Results: At admission, those with long DUI were more likely to have lower scores on tension derived from the Present State Examination, exhibited more behaviour threatening to others and more bizarre behaviour, were more likely to be single, to live alone or dependently, to be unemployed and to have experienced more adverse life events prior to admission. Logistic regression showed that diminished tension, bizarre behaviour and unemployed status independently increased the risk of relapse, bizarre behaviour making the single biggest contribution. Tension did not remain significant with log-transformation of data.

Conclusions: Findings are consistent with the conclusion that long DUI can reflect characteristics of the psychosis itself rather than delay in treatment.