EFFECTS OF KETAMINE ON EXPLICIT AND IMPLICIT SUICIDAL COGNITION: A RANDOMIZED CONTROLLED TRIAL IN TREATMENT-RESISTANT DEPRESSION
- 25 March 2014
- journal article
- research article
- Published by Hindawi Limited in Depression and Anxiety
- Vol. 31 (4), 335-343
- https://doi.org/10.1002/da.22253
Abstract
Preliminary evidence suggests intravenous ketamine has rapid effects on suicidal cognition, making it an attractive candidate for depressed patients at imminent risk of suicide. In the first randomized controlled trial of ketamine using an anesthetic control condition, we tested ketamine's acute effects on explicit suicidal cognition and a performance-based index of implicit suicidal cognition (Implicit Association Test; IAT) previously linked to suicidal behavior. Symptomatic patients with treatment-resistant unipolar major depression (inadequate response to ≥3 antidepressants) were assessed using a composite index of explicit suicidal ideation (Beck Scale for Suicidal Ideation, Montgomery-Asberg Rating Scale suicide item, Quick Inventory of Depressive Symptoms suicide item) and the IAT to assess suicidality implicitly. Measures were taken at baseline and 24 hr following a single subanesthetic dose of ketamine (n = 36) or midazolam (n = 21), a psychoactive placebo agent selected for its similar, rapid anesthetic effects. Twenty four hours postinfusion, explicit suicidal cognition was significantly reduced in the ketamine but not the midazolam group. Fifty three percent of ketamine-treated patients scored zero on all three explicit suicide measures at 24 hr, compared with 24% of the midazolam group (χ(2) = 4.6; P = .03). Implicit associations between self- and escape-related words were reduced following ketamine (P = .01; d = .58) but not midazolam (P = .68; d = .09). Ketamine-specific decreases in explicit suicidal cognition were largest in patients with elevated suicidal cognition at baseline, and were mediated by decreases in nonsuicide-related depressive symptoms. Intravenous ketamine produces rapid reductions in suicidal cognition over and above active placebo. Further study is warranted to test ketamine's antisuicidal effects in higher-risk samples.Keywords
This publication has 41 references indexed in Scilit:
- Connecting Inflammation with Glutamate Agonism in SuicidalityNeuropsychopharmacology, 2013
- Replication of Ketamine's Antidepressant Efficacy in Bipolar Depression: A Randomized Controlled Add-On TrialBiological Psychiatry, 2012
- A preliminary naturalistic study of low-dose ketamine for depression and suicide ideation in the emergency departmentInternational Journal of Neuropsychopharmacology, 2011
- mTOR-Dependent Synapse Formation Underlies the Rapid Antidepressant Effects of NMDA AntagonistsScience, 2010
- Rapid Resolution of Suicidal Ideation After a Single Infusion of anN-Methyl-D-Aspartate Antagonist in Patients With Treatment-Resistant Major Depressive DisorderThe Journal of Clinical Psychiatry, 2010
- Effects of Intravenous Ketamine on Explicit and Implicit Measures of Suicidality in Treatment-Resistant DepressionBiological Psychiatry, 2009
- Suicide and Suicidal BehaviorEpidemiologic Reviews, 2008
- Prediction of suicide ideation and attempts among adolescents using a brief performance-based test.Journal of Consulting and Clinical Psychology, 2007
- The moderator–mediator variable distinction in social psychological research: Conceptual, strategic, and statistical considerations.Journal of Personality and Social Psychology, 1986
- A New Depression Scale Designed to be Sensitive to ChangeThe British Journal of Psychiatry, 1979