Increased orexin levels in the cerebrospinal fluid the first year after a suicide attempt

J Affect Disord. 2009 Feb;113(1-2):179-82. doi: 10.1016/j.jad.2008.04.011. Epub 2008 Jun 3.


Background: The orexins (hypocretins) and cocaine and amphetamine regulated transcript (CART) are hypothalamic peptides involved in the regulation of sleep and appetite. We have previously shown that levels of both orexin-A and CART in the cerebrospinal fluid (CSF) are related to specific psychiatric symptoms.

Methods: Ten patients took part in lumbar punctures and psychiatric evaluations in conjunction to a suicide attempt and after 6 and 12 months. We measured CSF-orexin and CART using radioimmunoassays.

Results: Mean CSF-orexin was significantly higher at the first and second follow-up than at the suicide attempt. In contrast, mean CSF-CART did not differ over time. Total SUAS scores, as well as ratings of CPRS item 66 (global illness) were significantly lower at follow-up. At one year, there was a significant negative correlation between the change in CSF-orexin and the change in total SUAS score.

Limitations: The number of patients who participated was relatively small.

Conclusions: Our results support the hypothesis that orexin is involved in psychiatric symptomatology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Female
  • Follow-Up Studies
  • Humans
  • Hypothalamus / metabolism
  • Intracellular Signaling Peptides and Proteins / cerebrospinal fluid*
  • Male
  • Nerve Tissue Proteins / cerebrospinal fluid*
  • Nerve Tissue Proteins / metabolism
  • Neuropeptides / cerebrospinal fluid*
  • Orexins
  • Radioimmunoassay
  • Suicide, Attempted / psychology*
  • Time Factors


  • HCRT protein, human
  • Intracellular Signaling Peptides and Proteins
  • Nerve Tissue Proteins
  • Neuropeptides
  • Orexins
  • cocaine- and amphetamine-regulated transcript protein