Neurocognitive effects of ketamine in treatment-resistant major depression: association with antidepressant response.
Psychopharmacology (Berl) 2013;
231:10.1007/s00213-013-3255-x. [PMID:
24022236 PMCID:
PMC3952038 DOI:
10.1007/s00213-013-3255-x]
[Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 08/16/2013] [Indexed: 12/21/2022]
Abstract
RATIONALE
The N-methyl-D-aspartate (NMDA) glutamate receptor antagonist ketamine has demonstrated rapid antidepressant effects in patients with treatment-resistant depression (TRD). Despite the promise of a novel and urgently needed treatment for refractory depression, concerns regarding potential adverse neurocognitive effects of ketamine remain.
OBJECTIVES
Although extensive research has been conducted in healthy volunteers, there is a paucity of studies examining the neurocognitive effects of ketamine in depressed patients. Therefore, the aims of the current study were to characterize the relationship between baseline neurocognition and antidepressant response to ketamine, measure the acute impact of ketamine on neurocognition, and investigate the relationship between acute neurocognitive effects of ketamine and antidepressant response.
METHODS
Neurocognitive functioning was assessed in 25 patients with TRD using a comprehensive battery: estimated premorbid intelligence quotient (IQ), current IQ, and tests from the MATRICS Consensus Cognitive Battery (MCCB). A subset of the MCCB was repeated immediately following a 40-min intravenous infusion of ketamine (0.5 mg/kg).
RESULTS
Patients who responded to ketamine 24 h following treatment had poorer baseline neurocognitive performance relative to nonresponders and, in particular, slower processing speed (F = 8.42; df = 23; p = 0.008). Ketamine was associated with selective impairments in memory recall, and the degree of cognitive change carried negative prognostic significance (e.g., negative cognitive effects immediately after ketamine predicted lower response rate at 24 h; Fisher's exact test two-sided p = 0.027).
CONCLUSIONS
Taken together, our findings suggest a potential baseline neurocognitive predictor of ketamine response and an inverse relationship between the cognitive effects of ketamine and antidepressant efficacy.
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