The evidence for ketamine treatment in older adults with psychiatric illness: a scoping review.

Background: 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 use in the general population, fewer studies have investigated the efficacy and tolerability of this treatment for older (age >60) adults.

Objectives: This review sought to compile the randomized controlled trials (RCTs) investigating the evidence for ketamine treatment in older adults with psychiatric disorders.

Eligibility criteria: Only RCTs published in English language journals, or with official English language translations, and human studies were included.

Sources of evidence: 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 post-traumatic stress disorder.

Charting methods: Covidence was used to extract and organize included studies.

Results: Our review yielded 14 RCTs and 2 post-hoc analyses evaluating ketamine treatment in older patients. Eight of these studies examined ketamine for the 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 no significant impact of ketamine on delirium incidence. Two studies showed a lower incidence of delirium in the ketamine group, but another study showed a higher incidence of delirium with ketamine. Four studies showed improvement in depressive symptoms with ketamine treatment, while the others showed a lack of improvement. Most reported side effects were mild.

Conclusion: Several studies have investigated ketamine for depression and delirium in older adults and show mixed results. This review reveals the paucity of current data on ketamine for other psychiatric conditions in older adults. It reaffirms that use of ketamine in older adults with psychiatric illness, including depression and delirium, remains an individual risk versus benefit analysis using shared decision making.