Each month our editorial team sifts through hundreds of papers and curates notable findings—for practitioners and informed readers who want to stay current with the evidence. Subscribe to the monthly Research Digest for expert analysis and concise summaries of key papers.
Treatment-resistant depression means depression that does not get better after usual treatments. Scientists do not all agree on one clear definition, which makes it hard to know exactly how common it is or which treatments work best. Using the definition that regulators often use, about 30% of people with depression…
This meta-analysis combined 20 randomized clinical trials up to February 22, 2019, and found that a single dose of ketamine produced rapid antidepressant effects that were strongest at 24 hours and that these effects were still detectable up to 7 days. The analysis also found that repeated ketamine doses helped…
This small open-label study tested whether a 12-session course of cognitive behavioral therapy (CBT) given alongside four intravenous ketamine infusions could help maintain ketamine's antidepressant effects in people with treatment-resistant depression. Sixteen patients started the study; 8 (50%) responded to ketamine and 7 (43.8%) reached remission in the first two…
Researchers tested repeated subcutaneous (under-the-skin) injections of racemic ketamine in people whose depression had not improved after at least two antidepressant trials. People got injections twice a week for 4 weeks and neither participants nor the raters knew which drug they were getting. When the study allowed higher, response-guided ketamine…
In an open-label pilot study, 32 adults (ages 22–72; 53% female) with ongoing suicidal thoughts took low-dose oral ketamine for six weeks (starting at 0.5 mg/kg and titrated up to 3.0 mg/kg). Average scores on the Beck Scale for Suicide Ideation fell from a high level before treatment to below…
The authors reviewed clinical trials registered on ClinicalTrials.gov up to February 21, 2020 that tested ketamine or its enantiomers for psychiatric conditions. They found 140 registered trials, most testing intravenous ketamine for mood disorders in early-phase studies, and concluded that more large, later-phase and maintenance studies are needed to answer…
(Reprinted with permission from The American Journal of Psychiatry 2019; 176:401-409).
