Persistent negative symptoms after first episode schizophrenia: A 2-year follow-up study

Background: The aimof this study is to determine the rate of persistent negative symptoms according to different criteria during two years of follow-up after first-episode schizophrenia. Methods: The study sample consisted of 105 patients with first-episode schizophrenia who completed at least 12 months of follow-up period. We used 6 different definitions of persistent negative symptoms (PNS) based on the Scale for the Assessment of Negative Symptoms subscale scores at seven time points throughout the follow-up. In some definitions of PNS, patients with suprathreshold depressive symptoms were excluded. Premorbid adjustment and baseline cognitive performances of the patients were assessed. Results: The PNS rates were between 14.2 and 27.9% in the first year and 11.1 and 25.8% in the second year. Seventy-eight percent of the patients who met the strictest PNS criteria during the first 12 months met the same criteria also during the second 12-month-period. Those with PNS had earlier onset, lower premorbid functioning, worse executive functioning and attention at baseline, and lower rates of working/studying during the 2-year follow-up. Duration of education and untreated psychosis are the independent variables that contribute to the PNS status at the first year of follow-up in logistic regression analysis. Conclusion: Our findings suggest that PNS has specific predictors and effect on the course of illness after first-episode schizophrenia. (C) 2014 Elsevier B. V. All rights reserved.