title: Mood and motor activity in euthymic bipolar disorder with sleep disturbance.
abstract: The aims of this observational study of patients with euthymic bipolar disorder and sleep disturbance were to 1) compare characteristics related to mood and sleep between two groups with stable and unstable rest-activity cycles and 2) detect between-group differences in motor activity patterns.
  
  
  
  43 patients wore an actigraph for 6-8 days while reporting daily mood and sleep. Patients were defined as having an unstable rest-activity cycle if their diurnal active period duration presented variation above 2h from the mean during one week: 22 patients had stable and 21 unstable rest-activity cycles. Mood variability was defined as at least moderate symptoms and a change across two levels on a 7-point mood scale during one week.
  
  
  
  Patients with unstable rest-activity cycles were younger (37 vs. 48 years, p=0.01) and displayed more mood variability (p=0.02). Ten of 11 patients diagnosed with delayed sleep phase disorder were in the unstable group (p<0.01), and the unstable group had later and more variable get-up-times and bedtimes. In actigraphy recordings, the mean activity counts per minute did not differ between groups, but the minute-to-minute variability was elevated (p=0.04) and increased relative to the overall variability (p=0.03).
  
  
  
  A relatively small study sample and a 1-week study period prevent exploration of long-term clinical implications of results.
  
  
  
  A subgroup of euthymic patients with bipolar disorder displayed unstable rest-activity cycles combined with mood variability and motor activity patterns that resemble findings in affective episodes.
authors.affiliation: Department of Neuroscience, NTNU, the Norwegian University of Science and Technology, Trondheim, Norway and Department of Psychiatry, St. Olav's University Hospital, P.O. box 3008 Lade, N-7441 Trondheim, Norway. Electronic address: karoline.krane-gartiser@ntnu.no.
authors.forename: Karoline
authors.initials: K
authors.lastname: Krane-Gartiser
authors.affiliation: Department of Neuroscience, NTNU, the Norwegian University of Science and Technology, Trondheim, Norway and Department of Psychiatry, St. Olav's University Hospital, P.O. box 3008 Lade, N-7441 Trondheim, Norway.
authors.forename: Mette Kvisten
authors.initials: MK
authors.lastname: Steinan
authors.affiliation: Department of Neuroscience, NTNU, the Norwegian University of Science and Technology, Trondheim, Norway and Department of Psychiatry, St. Olav's University Hospital, P.O. box 3008 Lade, N-7441 Trondheim, Norway.
authors.forename: Knut
authors.initials: K
authors.lastname: Langsrud
authors.affiliation: Department of Neuroscience, NTNU, the Norwegian University of Science and Technology, Trondheim, Norway and Department of Psychiatry, St. Olav's University Hospital, P.O. box 3008 Lade, N-7441 Trondheim, Norway.
authors.forename: Vegard
authors.initials: V
authors.lastname: Vestvik
authors.affiliation: Department of Neuroscience, NTNU, the Norwegian University of Science and Technology, Trondheim, Norway and Department of Neurology, St. Olav's University Hospital, Trondheim, Norway.
authors.forename: Trond
authors.initials: T
authors.lastname: Sand
authors.affiliation: Department of Clinical Medicine, Section for Psychiatry, Faculty of Medicine and Dentistry, University of Bergen, Norway and Division of Psychiatry, Haukeland University Hospital, Bergen, Norway.
authors.forename: Ole Bernt
authors.initials: OB
authors.lastname: Fasmer
authors.affiliation: Department of Neuroscience, NTNU, the Norwegian University of Science and Technology, Trondheim, Norway and Department of Psychiatry, St. Olav's University Hospital, P.O. box 3008 Lade, N-7441 Trondheim, Norway.
authors.forename: Håvard
authors.initials: H
authors.lastname: Kallestad
authors.affiliation: Department of Neuroscience, NTNU, the Norwegian University of Science and Technology, Trondheim, Norway and Department of Psychiatry, St. Olav's University Hospital, P.O. box 3008 Lade, N-7441 Trondheim, Norway.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Morken
mesh_terms: D000328:Adult; D000339:Affect; D000367:Age Factors; D001714:Bipolar Disorder / Q000150:complications* / Q000523:psychology; D002940:Circadian Rhythm; D003527:Cyclothymic Disorder / Q000150:complications* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D012146:Rest / Q000502:physiology*; D012890:Sleep; D012893:Sleep Wake Disorders / Q000175:diagnosis / Q000209:etiology*
keywords: Chronobiology; Circadian rhythm; Euthymic bipolar disorder; Mood variability; Motor activity; Sleep disturbance