Decreased expression of nociceptin/orphanin FQ in the dorsal anterior cingulate cortex of suicides

Eur Neuropsychopharmacol. 2015 Nov;25(11):2008-14. doi: 10.1016/j.euroneuro.2015.08.015. Epub 2015 Aug 24.


The nociceptin/orphanin FQ (N/OFQ)-Nociceptin Opiod-like Peptide (NOP) receptor system is a critical mediator of physiological and pathological processes involved in emotional regulation and drug addiction. As such, this system may be an important biological substrate underlying psychiatric conditions that contribute to the risk of suicide. Thus, the goal of the present study was to characterize changes in human N/OFQ and NOP signaling as a function of depression, addiction and suicide. We quantified the expression of N/OFQ and NOP by RT-PCR in the anterior insula, the mediodorsal thalamus, and the dorsal anterior cingulate cortex (dACC) from a large sample of individuals who died by suicide and matched psychiatrically-healthy controls. Suicides displayed an 18% decrease in the expression of N/OFQ in the dACC that was not accounted for by current depressive or substance use disorders at the time of death. Therefore, our results suggest that dysregulation of the N/OFQ-NOP system may contribute to the neurobiology of suicide, a hypothesis that warrants further exploration.

Keywords: Addiction; Anterior Cingulate Cortex; Depression; Nociceptin Opiod-like Peptide receptor; Nociceptin/Orphanin FQ; Suicide.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Female
  • Gyrus Cinguli / metabolism*
  • Humans
  • Male
  • Middle Aged
  • Opioid Peptides / metabolism
  • Polymerase Chain Reaction
  • Protein Precursors / metabolism*
  • RNA, Messenger / metabolism
  • Receptors, Opioid / metabolism*
  • Suicide*
  • Thalamus / metabolism


  • Opioid Peptides
  • Protein Precursors
  • RNA, Messenger
  • Receptors, Opioid
  • prepronociceptin
  • nociceptin
  • nociceptin receptor