Enduring negative symptoms in first-episode psychosis: comparison of six methods using follow-up data

Targeted intervention in the early treatment of enduring positive and negat ive symptoms in first-episode psychosis is contingent on adequate case-iden tification procedures. Six methods of determining enduring negative symptom s in a sample of 238 individuals with first-episode psychosis who were asse ssed at three time points over a 12-month period are described. Results wer e examined at each of the seven combinations of follow-up points, revealing a highly fluid pattern. The percentage of the sample achieving caseness va ried dramatically, depending on the method used. Compared with non-cases, t he enduring negative symptom group had significantly lower scores on qualit y of life, poorer premorbid adjustment, and longer durations of prodrome an d untreated psychosis. Notwithstanding the 'ebb and flow' of negative sympt oms in first-episode psychosis, the results suggest that early identificati on of enduring negative symptoms is a feasible goal. (C) 1999 Elsevier Scie nce B.V. All rights reserved.