title: Lempel-Ziv complexity in schizophrenia: a MEG study.
abstract: OBJECTIVE
  The neurodevelopmental-neurodegenerative debate is a basic issue in the field of the neuropathological basis of schizophrenia (SCH). Neurophysiological techniques have been scarcely involved in such debate, but nonlinear analysis methods may contribute to it.
  
  
  METHODS
  Fifteen patients (age range 23-42 years) matching DSM IV-TR criteria for SCH, and 15 sex- and age-matched control subjects (age range 23-42 years) underwent a resting-state magnetoencephalographic evaluation and Lempel-Ziv complexity (LZC) scores were calculated.
  
  
  RESULTS
  Regression analyses indicated that LZC values were strongly dependent on age. Complexity scores increased as a function of age in controls, while SCH patients exhibited a progressive reduction of LZC values. A logistic model including LZC scores, age and the interaction of both variables allowed the classification of patients and controls with high sensitivity and specificity.
  
  
  CONCLUSIONS
  Results demonstrated that SCH patients failed to follow the "normal" process of complexity increase as a function of age. In addition, SCH patients exhibited a significant reduction of complexity scores as a function of age, thus paralleling the pattern observed in neurodegenerative diseases.
  
  
  CONCLUSIONS
  Our results support the notion of a progressive defect in SCH, which does not contradict the existence of a basic neurodevelopmental alteration.
authors: Department of Psychiatry and Psychological Medicine, Complutense University, Madrid, Spain. aferlucas@med.ucm.es
authors: Alberto
authors: A
authors: Fernández
authors: María-Inés
authors: MI
authors: López-Ibor
authors: Agustín
authors: A
authors: Turrero
authors: Juan-Matías
authors: JM
authors: Santos
authors: María-Dolores
authors: MD
authors: Morón
authors: Roberto
authors: R
authors: Hornero
authors: Carlos
authors: C
authors: Gómez
authors: María Andreina
authors: MA
authors: Méndez
authors: Tomás
authors: T
authors: Ortiz
authors: Juan José
authors: JJ
authors: López-Ibor