title: Mu opioid receptor availability in people with psychiatric disorders who died by suicide: a case control study.
abstract: BACKGROUND
  Mu opioid receptors have previously been shown to be altered in people with affective disorders who died as a result of suicide. We wished to determine whether these changes were more widespread and independent of psychiatric diagnoses.
  
  
  METHODS
  Mu receptor levels were determined using [3 H]DAMGO binding in BA24 from 51 control subjects; 38 people with schizophrenia (12 suicides); 20 people with major depressive disorder (15 suicides); 13 people with bipolar disorder (5 suicides) and 9 people who had no history of psychiatric disorders but who died as a result of suicide. Mu receptor levels were further determined in BA9 and caudate-putamen from 38 people with schizophrenia and 20 control subjects using [3 H]DAMGO binding and, in all three regions, using Western blots. Data was analysed using one-way ANOVAs with Bonferroni's Multiple Comparison Test or, where data either didn't approximate to a binomial distribution or the sample size was too small to determine distribution, a Kruskal-Wallis test with Dunn's Multiple Comparison Test.
  
  
  RESULTS
  [3 H]DAMGO binding density was lower in people who had died as a result of suicide (p<0.01). People with schizophrenia who had died as a result of suicide had lower binding than control subjects (p<0.001), whilst people with bipolar disorder (non- suicide) had higher levels of binding (p<0.05). [3 H]DAMGO binding densities, but not mu protein levels, were significantly decreased in BA9 from people with schizophrenia who died as a result of suicide (p<0.01).
  
  
  CONCLUSIONS
  Overall these data suggest that mu opioid receptor availability is decreased in the brains of people with schizophrenia who died as a result of suicide, which would be consistent with increased levels of endogenous ligands occupying these receptors.
authors.affiliation: Molecular Psychiatry Laboratory, Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, VIC 3010, Australia. elscarr@unimelb.edu.au
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Scarr
authors.forename: Tammie Terese
authors.initials: TT
authors.lastname: Money
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Pavey
authors.forename: Jaclyn
authors.initials: J
authors.lastname: Neo
authors.forename: Brian
authors.initials: B
authors.lastname: Dean
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000235:genetics / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017450:Receptors, Opioid, mu / Q000235:genetics / Q000378:metabolism*; D012559:Schizophrenia / Q000235:genetics / Q000378:metabolism*; D013405:Suicide
chemical_list: D017450:Receptors, Opioid, mu