title: A longitudinal study of symptom dimensions in schizophrenia. Prediction and patterns of change.
abstract: BACKGROUND
  Factor analytic studies have suggested that the symptoms of schizophrenia may be divided into three uncorrelated dimensions. This study examines the longitudinal course of the symptoms of schizophrenia using this three-dimensional perspective.
  
  
  METHODS
  The sample was composed primarily of neuroleptic-naive patients suffering from schizophrenia. Subjects were studied in a prospective longitudinal design, with comprehensive structured assessments at index, discharge, and 6-month intervals after discharge over a 2-year period.
  
  
  RESULTS
  Negative symptoms were already relatively prominent at the time of index evaluation; they tended to remain stable throughout the follow-up period. The two dimensions of positive symptoms, psychoticism and disorganization, although prominent at index evaluation, declined over the course of the follow-up period and tended to be less stable. A longitudinal factor analysis was conducted to determine whether the changes in symptoms followed any consistent pattern. We observed that all three groups of symptoms tended to change in unison and independently from one another.
  
  
  CONCLUSIONS
  These results suggest that these three dimensions of psychopathology show different patterns of exacerbation and remission during the course of schizophrenia. This independent pattern of evolution suggests that these three dimensions should be studied further with respect to response to treatment, cognitive mechanisms, psychosocial correlates, and neural substrates.
authors.affiliation: Mental Health Clinical Research Center, University of Iowa Hospitals and Clinics, Iowa City, USA.
authors.forename: S
authors.initials: S
authors.lastname: Arndt
authors.forename: N C
authors.initials: NC
authors.lastname: Andreasen
authors.forename: M
authors.initials: M
authors.lastname: Flaum
authors.forename: D
authors.initials: D
authors.lastname: Miller
authors.forename: P
authors.initials: P
authors.lastname: Nopoulos
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D005163:Factor Analysis, Statistical; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008959:Models, Neurological; D008960:Models, Psychological; D011336:Probability; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012559:Schizophrenia / Q000175:diagnosis*; D012565:Schizophrenic Psychology; D012720:Severity of Illness Index