Is the association between duration of untreated psychosis and outcome confounded? A two year follow-up study of first-admitted patients

Objective. To assess whether a long duration of untreated psychosis (DUP) b efore first admission predicts poor clinical and social outcome, and whethe r this association, if any, is confounded by premorbid and clinical charact eristics. Method. A population-based sample of first-admitted subjects with psychosis (n = 65) was assessed at six monthly intervals over a two year follow-up u sing multiple sources of information. Results. Most subjects (87%) with a life-chart 'continuous' course of psych otic symptoms had a history of a. 'long' delay between onset of psychotic s ymptoms and first admission (greater than or equal to3 months, median split ), compared with 55% of subjects with a course of 'neither episodic nor con tinuous', 42% of subjects with an 'episodic' course, and 33% of subjects wi th 'no psychotic symptoms' during the follow-up period (RR = 9; 95%CI 1.5-5 4.8, P = 0.02). The strength of association between DUP and continuous cour se of psychosis was strongly reduced (63%) after adjustment for premorbid f unctioning, and to a lesser extent for the severity of illness and for the intensity of negative symptoms at first admission. Conclusions. The association between DUP and poor outcome may be spurious, confounded by the fact that poor premorbid functioning is independently ass ociated with both DUP and poor outcome, with no direct causal link between these two latter variables. DW may also be on the causal pathway between po or premorbid functioning and poor outcome, poor adjustment delaying access to care, and subsequently increasing the risk of presenting with a non-remi tting course of illness. The links between premorbid functioning, DUP and o utcome have to be further explored to clarify the directions of the associa tions between these variables. (C) 2001 Elsevier Science B.V. All rights re served.