title: Actigraphic assessment of motor activity in acutely admitted inpatients with bipolar disorder.
abstract: BACKGROUND
  Mania is associated with increased activity, whereas psychomotor retardation is often found in bipolar depression. Actigraphy is a promising tool for monitoring phase shifts and changes following treatment in bipolar disorder. The aim of this study was to compare recordings of motor activity in mania, bipolar depression and healthy controls, using linear and nonlinear analytical methods.
  
  
  METHODS
  Recordings from 18 acutely hospitalized inpatients with mania were compared to 12 recordings from bipolar depression inpatients and 28 healthy controls. 24-hour actigraphy recordings and 64-minute periods of continuous motor activity in the morning and evening were analyzed. Mean activity and several measures of variability and complexity were calculated.
  
  
  RESULTS
  Patients with depression had a lower mean activity level compared to controls, but higher variability shown by increased standard deviation (SD) and root mean square successive difference (RMSSD) over 24 hours and in the active morning period. The patients with mania had lower first lag autocorrelation compared to controls, and Fourier analysis showed higher variance in the high frequency part of the spectrum corresponding to the period from 2-8 minutes. Both patient groups had a higher RMSSD/SD ratio compared to controls. In patients with mania we found an increased complexity of time series in the active morning period, compared to patients with depression. The findings in the patients with mania are similar to previous findings in patients with schizophrenia and healthy individuals treated with a glutamatergic antagonist.
  
  
  CONCLUSIONS
  We have found distinctly different activity patterns in hospitalized patients with bipolar disorder in episodes of mania and depression, assessed by actigraphy and analyzed with linear and nonlinear mathematical methods, as well as clear differences between the patients and healthy comparison subjects.
authors.affiliation: Department of Neuroscience, the Norwegian University of Science and Technology, Trondheim, Norway and Department of Psychiatry, St. Olav's University Hospital, Trondheim, Norway.
authors.forename: Karoline
authors.initials: K
authors.lastname: Krane-Gartiser
authors.affiliation: Department of Clinical Medicine, Section for Psychiatry, Faculty of Medicine and Dentistry, University of Bergen, Bergen, Norway, Division of Mental Health Care, Valen Hospital, Fonna Regional Health Authority, Norway and MoodNet Research Group, Division of Psychiatry, Haukeland University Hospital, Bergen, Norway.
authors.forename: Tone Elise Gjotterud
authors.initials: TE
authors.lastname: Henriksen
authors.affiliation: Department of Neuroscience, the Norwegian University of Science and Technology, Trondheim, Norway and Department of Psychiatry, St. Olav's University Hospital, Trondheim, Norway.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Morken
authors.affiliation: Department of Neuroscience, the Norwegian University of Science and Technology, Trondheim, Norway and Department of Psychiatry, St. Olav's University Hospital, Trondheim, Norway.
authors.forename: Arne
authors.initials: A
authors.lastname: Vaaler
authors.affiliation: Department of Clinical Medicine, Section for Psychiatry, Faculty of Medicine and Dentistry, University of Bergen, Bergen, Norway, Division of Mental Health Care, Valen Hospital, Fonna Regional Health Authority, Norway and MoodNet Research Group, Division of Psychiatry, Haukeland University Hospital, Bergen, Norway.
authors.forename: Ole Bernt
authors.initials: OB
authors.lastname: Fasmer
mesh_terms: D056044:Actigraphy / Q000379:methods*; D000328:Adult; D001714:Bipolar Disorder / Q000503:physiopathology*; D016022:Case-Control Studies; D003866:Depressive Disorder / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007297:Inpatients / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D011379:Prognosis; D012559:Schizophrenia / Q000503:physiopathology*