title: Lateralized movement-related potential amplitudes differentiate between schizophrenia/schizoaffective disorder and major depression.
abstract: OBJECTIVE
  To examine whether deficits in focal lateralized motor system activation would differentiate between subjects with schizophrenia/schizoaffective disorder and subjects with a major depressive episode. Reductions of Bereitschaftspotential amplitude have been described for both diagnostic groups.
  
  
  METHODS
  We analyzed multi-channel lateralized movement-related potentials (LMRP) during choice reaction movements in 16 schizophrenic/schizoaffective patients in partial remission with predominant negative symptoms, 18 patients with a non-psychotic major depression and two healthy control groups age-matched to the respective patient groups (20/23 subjects).
  
  
  RESULTS
  A significant reduction of lateralized potentials over the (pre-)motor areas immediately preceding and around movement execution was found only in subjects with schizophrenia/schizoaffective disorder but not with a major depressive episode. Reduced LMRP amplitudes correlated with negative symptoms (SANS score). Other movement stages (preceding response-locked 'contingent negative variation' during response selection and post-movement evaluation during motor postimperative negative variation) were not affected in the same way.
  
  
  CONCLUSIONS
  Deficits in focal motor cortex activation during movement execution may reflect rather schizophrenia-specific deficits in fronto-striatal circuits. A general lack of drive and depressed mood did not alter the degree of lateralization of motor activation during movement execution.
  
  
  CONCLUSIONS
  Lateralization of movement-related potentials could differentiate psychotic from non-psychotic disorders on the group level.
authors.affiliation: Section for Experimental Psychopathology, Psychiatric Hospital, University of Heidelberg, Voßstraße 4, 69115 Heidelberg, Germany. Stephan.Bender@uniklinikum-dresden.de
authors.forename: Stephan
authors.initials: S
authors.lastname: Bender
authors.forename: Laura
authors.initials: L
authors.lastname: Melendez
authors.forename: Johannes
authors.initials: J
authors.lastname: Schröder
authors.forename: Veit
authors.initials: V
authors.lastname: Roessner
authors.forename: Franz
authors.initials: F
authors.lastname: Resch
authors.forename: Matthias
authors.initials: M
authors.lastname: Weisbrod
mesh_terms: D000328:Adult; D002755:Choice Behavior / Q000502:physiology; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000503:physiopathology; D003937:Diagnosis, Differential; D004569:Electroencephalography; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D009068:Movement / Q000502:physiology; D011618:Psychotic Disorders / Q000175:diagnosis* / Q000503:physiopathology; D011930:Reaction Time / Q000502:physiology; D012559:Schizophrenia / Q000175:diagnosis* / Q000503:physiopathology