PLoS ONE (Jan 2011)

Scaling behavior of human locomotor activity amplitude: association with bipolar disorder.

  • Premananda Indic,
  • Paola Salvatore,
  • Carlo Maggini,
  • Stefano Ghidini,
  • Gabriella Ferraro,
  • Ross J Baldessarini,
  • Greg Murray

DOI
https://doi.org/10.1371/journal.pone.0020650
Journal volume & issue
Vol. 6, no. 5
p. e20650

Abstract

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Scale invariance is a feature of complex biological systems, and abnormality of multi-scale behaviour may serve as an indicator of pathology. The hypothalamic suprachiasmatic nucleus (SCN) is a major node in central neural networks responsible for regulating multi-scale behaviour in measures of human locomotor activity. SCN also is implicated in the pathophysiology of bipolar disorder (BD) or manic-depressive illness, a severe, episodic disorder of mood, cognition and behaviour. Here, we investigated scaling behaviour in actigraphically recorded human motility data for potential indicators of BD, particularly its manic phase. A proposed index of scaling behaviour (Vulnerability Index [VI]) derived from such data distinguished between: [i] healthy subjects at high versus low risk of mood disorders; [ii] currently clinically stable BD patients versus matched controls; and [iii] among clinical states in BD patients.