title: Gait unsteadiness and fall risk in two affective disorders: a preliminary study.
abstract: BACKGROUND
  In older adults, depression has been associated with increased fall risk, but the reasons for this link are not fully clear. Given parallels between major depression and Parkinson's disease, we hypothesized that major depression and related affective disorders would be associated with impairment in the ability to regulate the stride-to-stride fluctuations in gait cycle timing.
  
  
  METHODS
  We measured stride-to-stride fluctuations of patients with two forms of mood disorders, unipolar major depressive disorder (MDD) and bipolar disorder, and compared their gait to that of a healthy control group. The primary outcomes were two measures of gait unsteadiness that have been associated with fall risk: stride time variability and swing time variability.
  
  
  RESULTS
  Compared to the control group, the two patient groups tended to walk more slowly and with decreased swing time and increased stride time. However, none of these differences was statistically significant. Compared to the control group, swing time variability was significantly larger in the subjects with bipolar disorder (p < 0.0001) and in the subjects with MDD (p < 0.0004).
  
  
  CONCLUSIONS
  Patients with MDD and patients with bipolar disorder display gait unsteadiness. This perturbation in gait may provide a mechanistic link connecting depression and falls. The present findings also suggest the possibility that measurement of variability of gait may provide a readily quantifiable objective approach to monitoring depression and related affective disorders.
authors.affiliation: Division on Aging, Harvard Medical School, Boston, MA, USA. jhausdor@bidmc.harvard.edu
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Hausdorff
authors.forename: Chung-Kang
authors.initials: CK
authors.lastname: Peng
authors.forename: Ary L
authors.initials: AL
authors.lastname: Goldberger
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Stoll
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data*; D000328:Adult; D000367:Age Factors; D000368:Aged; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000503:physiopathology; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D005684:Gait / Q000502:physiology*; D020233:Gait Disorders, Neurologic / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D004856:Postural Balance / Q000502:physiology; D012307:Risk Factors; D016138:Walking / Q000502:physiology