Background
Intravenous ketamine has shown rapid antidepressant effects in early trials, making
it a potentially attractive candidate for depressed patients at imminent risk of suicide.
The Implicit Association Test (IAT), a performance-based measure of association between
concepts, may have utility in suicide assessment.
Methods
Twenty-six patients with treatment-resistant depression were assessed using the suicidality
item of the Montgomery-Asberg Depression Rating Scale (MADRS-SI) 2 hours before and
24 hours following a single subanesthetic dose of intravenous ketamine. Ten patients
also completed IATs assessing implicit suicidal associations at comparable time points.
In a second study, nine patients received thrice-weekly ketamine infusions over a
12-day period.
Results
Twenty-four hours after a single infusion, MADRS-SI scores were reduced on average
by 2.08 points on a 0 to 6 scale (p < .001; d = 1.37), and 81% of patients received a rating of 0 or 1 postinfusion. Implicit suicidal
associations were also reduced following ketamine (p = .003; d = 1.36), with reductions correlated across implicit and explicit measures. MADRS-SI
reductions were sustained for 12 days by repeated-dose ketamine (p < .001; d = 2.42).
Conclusions
These preliminary findings support the premise that ketamine has rapid beneficial
effects on suicidal cognition and warrants further study.
Key Words
To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to Biological PsychiatryAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- Relief of expressed suicidal intent by ECT: A consortium for research in ECT study.Am J Psychiatry. 2005; 162: 977-982
- Occurrence and course of suicidality during short-term treatment of late-life depression.Arch Gen Psychiatry. 2003; 60: 610-617
- Prediction of suicide ideation and attempts among adolescents using a brief performance-based test.J Consult Clin Psychol. 2007; 75: 707-715
- Clinical correlates of inpatient suicide.J Clin Psychiatry. 2003; 64: 14-19
- Measuring individual differences in implicit cognition: The implicit association test.J Pers Soc Psychol. 1998; 74: 1464-1480
- Implicit attitude measures: Consistency, stability, and convergent validity.Psychol Sci. 2001; 12: 163-170
- Implicit attitudes towards homosexuality: Reliability, validity, and controllability of the IAT.J Exp Psychol. 2001; 48: 145-160
Greenwald AG, Poehlman TA, Uhlmann EL, Banaji MR (in press): Understanding and using the Implicit Association test. III. Meta-analysis of predictive validity. J Pers Soc Psychol.
- Assessment of self-injurious thoughts using a behavioral test.Am J Psychiatry. 2007; 164: 820-823
- Measuring implicit associations about suicide.(Paper presented at: Annual Convention of the Association for Behavioral and Cognitive Therapies; November 13–16, 2008; Orlando, FL)2008
- A randomized trial of an N-methyl-D-aspartate antagonist in treatment-resistant major depression.Arch Gen Psychiatry. 2006; 63: 856-864
- Antidepressant effects of ketamine in depressed patients.Biol Psychiatry. 2000; 47: 351-354
- Riluzole for relapse prevention following intravenous ketamine in treatment-resistant depression: A pilot randomized, placebo-controlled continuation trial.Int J Neuropsychopharmacol. 2009; 17: 1-12
- The definition and meaning of treatment-resistant depression.J Clin Psychiatry. 2001; 62: 10-17
- The Inventory of Depressive Symptomatology (IDS): Psychometric properties.Psychol Med. 1996; 26: 477-486
- A new depression scale designed to be sensitive to change.Br J Psychiatry. 1979; 134: 382-389
- Manual for the Beck Scale for Suicide Ideation.Psychological Corporation, San Antonio, TX1991
- Understanding and using the Implicit Association Test.Pers Soc Psychol Bull. 2005; 31: 166-180
- Statistical Power Analysis for the Behavioral Sciences.Lawrence Erlbaum Associates, Hillsdale, NJ1988
Article info
Publication history
Published online: June 22, 2009
Accepted:
April 28,
2009
Received in revised form:
April 14,
2009
Received:
February 4,
2009
Identification
Copyright
© 2009 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.
