title: Associations between suicide attempts and elevated bedtime salivary cortisol levels in bipolar disorder.
abstract: BACKGROUND
  Hypothalamic-pituitary-adrenal (HPA) axis abnormalities have been reported in bipolar disorder and also in suicidal behavior, but few studies have examined the relationship between suicidal behaviors and the HPA axis function in bipolar disorder, attending to and minimizing confounding factors. We compare HPA axis activity in bipolar individuals with and without suicidal behavior and unaffected healthy controls through measurement of salivary cortisol.
  
  
  METHODS
  Salivary cortisol was collected for three consecutive days in 29 controls, 80 bipolar individuals without a history of suicide and 56 bipolar individuals with a past history of suicide. Clinical factors that affect salivary cortisol were also examined.
  
  
  RESULTS
  A past history of suicide was associated with a 7.4% higher bedtime salivary cortisol level in bipolar individuals. There was no statistical difference between non-suicidal bipolar individuals and controls in bedtime salivary cortisol and awakening salivary cortisol was not different between the three groups.
  
  
  CONCLUSIONS
  The measure of salivary cortisol was a home based collection by the study subjects and the retrospective clinical data was primarily based on their historical account.
  
  
  CONCLUSIONS
  Bipolar individuals with a past history of suicidal behavior exhibit hyperactivity in the HPA axis. This biological marker remains significant regardless of demographic factors, mood state, severity and course of illness. This finding in bipolar disorder is consistent with the evidence for altered HPA axis functioning in suicide and mood disorders and is associated with a clinical subgroup of bipolar patients at elevated risk for suicide based on their history, and in need of further attention and study.
authors.affiliation: The University of Michigan, Department of Psychiatry and Depression Center, Ann Arbor, MI 48109-2700, USA. masoud@med.umich.edu
authors.forename: Masoud
authors.initials: M
authors.lastname: Kamali
authors.forename: Erika F H
authors.initials: EF
authors.lastname: Saunders
authors.forename: Alan R
authors.initials: AR
authors.lastname: Prossin
authors.forename: Christine B
authors.initials: CB
authors.lastname: Brucksch
authors.forename: Gloria J
authors.initials: GJ
authors.lastname: Harrington
authors.forename: Scott A
authors.initials: SA
authors.lastname: Langenecker
authors.forename: Melvin G
authors.initials: MG
authors.lastname: McInnis
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis; D001714:Bipolar Disorder / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis*; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010913:Pituitary-Adrenal System / Q000503:physiopathology; D012463:Saliva / Q000737:chemistry*; D013406:Suicide, Attempted; D055815:Young Adult
chemical_list: D015415:Biomarkers; D006854:Hydrocortisone