title: Electronic monitoring of psychomotor activity as a supplementary objective measure of depression severity.
abstract: BACKGROUND
  Rating scales used to assess the severity of depression e.g. the Hamilton Depression Rating Scale 17-item (HDRS-17) partly rely on the patient's subjective experience and reporting. Such subjective measures tend to have low reliability and adding objective measures to complement the assessment of depression severity would be a major step forward.
  
  
  OBJECTIVE
  To investigate correlations between electronic monitoring of psychomotor activity and severity of depression according to HDRS-17.
  
  
  METHODS
  A total of 36 patients with unipolar disorder (n = 18) or bipolar disorder (n = 18) and 31 healthy control persons aged 18-60 years were included. Psychomotor activity was measured using a combined heart rate and movement sensor device (Actiheart) for 3 consecutive days, 24 h a day.
  
  
  RESULTS
  We found that sleeping heart rate (beats/min) correlated with HDRS-17 in both patients with unipolar disorder and bipolar disorder (unadjusted model: B = 0.46, 95% CI 0.037-0.89, P = 0.034). In contrast, correlations between activity energy expenditure (kJ/kg/day), cardio-respiratory fitness (mlO2/min/kg) and HDRS-17 were non-significant.
  
  
  CONCLUSIONS
  These results suggest that measuring sleeping heart rate in non-experimental daily life could be an objective supplementary method to measure the severity of depression and perhaps indicate presence of insomnia.
authors.affiliation: The Clinic for Affective Disorders, Psychiatric Centre Copenhagen , Denmark.
authors.forename: Maria
authors.initials: M
authors.lastname: Faurholt-Jepsen
authors.forename: Søren
authors.initials: S
authors.lastname: Brage
authors.forename: Maj
authors.initials: M
authors.lastname: Vinberg
authors.forename: Hans Mørch
authors.initials: HM
authors.lastname: Jensen
authors.forename: Ellen Margrethe
authors.initials: EM
authors.lastname: Christensen
authors.forename: Ulla
authors.initials: U
authors.lastname: Knorr
authors.forename: Lars Vedel
authors.initials: LV
authors.lastname: Kessing
mesh_terms: D000293:Adolescent; D000328:Adult; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology; D016022:Case-Control Studies; D003866:Depressive Disorder / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000379:methods; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance / Q000502:physiology*; D015203:Reproducibility of Results; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D055815:Young Adult
keywords: Bipolar disorder; Hamilton Depression Rating Scale 17-item; Heart rate and movement sensor; Psychomotor activity; Unipolar disorder