title: Psychomotor retardation is linked to frontal alpha asymmetry in major depression.
abstract: BACKGROUND
  Psychomotor disturbances are a main clinical feature of major depressive disorder (MDD) but little is known about their EEG signature. One of the most replicated EEG findings in MDD is resting frontal asymmetry in the alpha band (FAA), which is thought to be a correlate of withdrawal behavior and reduced approach motivation. The purpose of this study was to assess psychomotor alterations, alpha band power, FAA and investigate the association between them.
  
  
  METHODS
  20 MDD patients and 19 healthy subjects were enrolled. Alpha power and FAA scores were calculated from a resting state EEG. Wrist actigraphy was recorded from the non-dominant arm for 24 h and activity level scores (AL) were extrapolated from the wakeful periods.
  
  
  RESULTS
  MDD patients had a left-lateralized frontal alpha activity and lower AL scores when compared to healthy subjects. A significant correlation was found between mean FAA and AL scores. A negative covariance between power in the lower alpha range and AL scores over the motor cortex bilaterally was detected.
  
  
  CONCLUSIONS
  Relatively small sample size. Patients were pharmacologically treated with antidepressants.
  
  
  CONCLUSIONS
  This study replicates the finding of left-lateralized FAA and lower AL scores in MDD patients, and establishes the first evidence of significant correlations between alpha power, FAA scores and measures of motor activity, which may be interpreted as an expression of impaired motivational drive in MDD.
authors.affiliation: Translational Research Center, University Hospital of Psychiatry, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland; NeuroFarBa department, Neuroscience Section, University of Florence, Largo Brambilla 3, 50134, Florence. Electronic address: andrea.cantisani@puk.unibe.ch.
authors.forename: Andrea
authors.initials: A
authors.lastname: Cantisani
authors.affiliation: Translational Research Center, University Hospital of Psychiatry, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Koenig
authors.affiliation: Translational Research Center, University Hospital of Psychiatry, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland.
authors.forename: Helge
authors.initials: H
authors.lastname: Horn
authors.affiliation: Translational Research Center, University Hospital of Psychiatry, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Müller
authors.affiliation: Translational Research Center, University Hospital of Psychiatry, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland.
authors.forename: Werner
authors.initials: W
authors.lastname: Strik
authors.affiliation: Translational Research Center, University Hospital of Psychiatry, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Walther
mesh_terms: D056044:Actigraphy; D000328:Adult; D000513:Alpha Rhythm / Q000502:physiology*; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000150:complications / Q000503:physiopathology*; D004292:Dominance, Cerebral / Q000502:physiology; D004569:Electroencephalography; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009042:Motivation; D011596:Psychomotor Disorders / Q000150:complications / Q000503:physiopathology*; D012146:Rest; D055815:Young Adult
keywords: Actigraphy; Alpha oscillations; EEG; Frontal alpha asymmetry; Major depression; Psychomotor disturbances