The course of negative symptoms in first-episode schizophrenia and its predictors: A prospective two-year follow-up study.

AIMS:This study aimed to investigate the course of negative symptoms and its stability over a two-year period following a first-episode schizophrenia (FES) and the possible predictors of higher severity in this symptomatology after this period. METHODS:In this longitudinal two-year prospective follow-up study we included 268 patients with a FES, according to DSM-IV. Analysis of variance was conducted in patients who completed the full follow-up to study changes in negative symptoms over three visits. Regression analyses were conducted to show correlates and potential predictors of negative symptoms at two-year follow-up. RESULTS:There was a significant effect for time in negative symptomatology, which was less severe at one-year follow-up after a FES and remained stable up to two years (Time 1>Time 2>Time 3); F(2,151)=20.45, p<0.001. Poorer premorbid adjustment (p=0.01) and higher negative symptoms at baseline (p<0.001) made a significant contribution to the changes in the negative symptoms severity at two-years after a FES (R2=0.21, p<0.001). CONCLUSIONS:We found a reduction in the negative symptomatology at one-year after a FES. This change remained stable at two-year. Our results suggested that the presence of this symptomatology early in the course of the illness, together with a poorer premorbid adjustment, predict more severe negative symptoms at mid-term outcome.