Abstract
Ketamine, an N-methyl-D-aspartate antagonist, has been used for decades as an anesthetic agent, but more recently it has been studied in psychiatric illness. Though ketamine has been investigated for treatment of several psychiatric conditions, including depression, anxiety, suicidal ideation, and delirium in the general population, fewer studies have investigated the efficacy and tolerability of this treatment for older (age > 60) adults. This review sought to compile the randomized controlled trials (RCTs) investigating the evidence for ketamine treatment in older adults with psychiatric disorders.
Our team searched PubMed, Cochrane Database, and Ovid with the terms ketamine, depression, suicidal ideation, bipolar disorder, mania, anxiety, schizophrenia, psychotic disorders, dementia, delirium, and PTSD. Only RCTs published in English language journals, or with official English language translations, and human studies were included.
Our review yielded 14 RCTs and 2 post-hoc analyses evaluating ketamine treatment in older patients. Eight of these studies examined ketamine for treatment of delirium, while the remaining eight examined its use in depression. The studies had significant heterogeneity so direct comparisons of the results were challenging. However, five studies showed that ketamine did not significantly impact delirium incidence. Two studies showed lower incidence of delirium in the ketamine group, but another showed higher incidence of delirium after receiving ketamine. Four studies showed improvement in depressive symptoms with ketamine treatment, while another four studies showed lack of improvement. Most reported side effects were mild and included perceptual disturbances, nausea, and vomiting.
Several studies have investigated ketamine for depression and delirium in older adults and show mixed results for both conditions. This review reveals the paucity of current data on ketamine for other psychiatric conditions in older adults. It reaffirms that further research is needed and use of ketamine in older adults with psychiatric illness, including depression and delirium, remains an individual risk versus benefit analysis using shared decision making.