title: Improvement in suicidal ideation after ketamine infusion: relationship to reductions in depression and anxiety.
abstract: OBJECTIVE
  Suicide is a psychiatric emergency. Currently, there are no approved pharmacologic treatments for suicidal ideation. Ketamine is an N-methyl-D-aspartate (NMDA) receptor antagonist that rapidly reduces suicidal ideation as well as depression and anxiety, but the dynamic between these symptoms is not known. The aim of this analysis was to evaluate whether ketamine has an impact on suicidal thoughts, independent of depressive and anxiety symptoms.
  
  
  METHODS
  133 patients with treatment-resistant depression (major depressive disorder or bipolar I/II disorder) received a single subanesthetic infusion of ketamine (0.5 mg/kg over 40 min). Post-hoc correlations and linear mixed models evaluated the relationship between suicidal ideation and depression and anxiety symptoms using the Hamilton Depression Rating Scale (HAMD), Scale for Suicidal Ideation (SSI), Beck Depression Inventory (BDI), and Hamilton Anxiety Rating Scale (HAMA) focusing on 230 min post-infusion.
  
  
  RESULTS
  At 230 min post-infusion, correlations between changes in suicidal ideation and depression ranged from 0.23 to 0.44 (p < .05), accounting for up to 19% in the variance of ideation change. Correlations with anxiety ranged from 0.23 to 0.40 (p < .05), accounting for similar levels of variance. Ketamine infusion was associated with significant reductions in suicidal ideation compared to placebo, when controlling for the effects of ketamine on depression (F1,587 = 10.31, p = .001) and anxiety (F1,567 = 8.54, p = .004).
  
  
  CONCLUSIONS
  Improvements in suicidal ideation after ketamine infusion are related to, but not completely driven by, improvements in depression and anxiety. Investigation of the specific effects of ketamine on suicidal thoughts is warranted.
authors.affiliation: Experimental Therapeutics & Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address: Elizabeth.Ballard@nih.gov.
authors.forename: Elizabeth D
authors.initials: ED
authors.lastname: Ballard
authors.affiliation: Experimental Therapeutics & Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Dawn F
authors.initials: DF
authors.lastname: Ionescu
authors.affiliation: Experimental Therapeutics & Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Vande Voort
authors.affiliation: Experimental Therapeutics & Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Niciu
authors.affiliation: Experimental Therapeutics & Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Erica M
authors.initials: EM
authors.lastname: Richards
authors.affiliation: Experimental Therapeutics & Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Luckenbaugh
authors.affiliation: Experimental Therapeutics & Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Brutsché
authors.affiliation: Experimental Therapeutics & Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Rezvan
authors.initials: R
authors.lastname: Ameli
authors.affiliation: Experimental Therapeutics & Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Maura L
authors.initials: ML
authors.lastname: Furey
authors.affiliation: Experimental Therapeutics & Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Zarate
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000700:Analgesics / Q000627:therapeutic use*; D003863:Depression / Q000188:drug therapy* / Q000523:psychology*; D005260:Female; D006801:Humans; D055104:Infusions, Subcutaneous; D007649:Ketamine / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D013223:Statistics as Topic; D059020:Suicidal Ideation; D055815:Young Adult
chemical_list: D000700:Analgesics; D007649:Ketamine
keywords: Depression; Ketamine; Suicidal ideation; Suicide