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.
This paper is a meta-analysis of more than 300 studies in humans that looked at links between psychological stress and measures of the immune system. It found that very short, acute stressors (minutes) were tied to increases in some natural (innate) immune measures and decreases in some specific (adaptive) immune…
This umbrella review looked at the best existing reviews and large studies to see if depression is linked to low serotonin or low serotonin activity. Across measures of serotonin in fluids, receptor and transporter studies, tryptophan depletion experiments, and large genetic studies, the evidence was mixed or absent. The authors…
This systematic review looked at 83 published reports on ketamine for mental health and substance use disorders. It found strong evidence that ketamine can produce rapid antidepressant and anti‑suicidal effects, but these benefits tend to be short‑lived. Evidence for other conditions was weaker but often showed similar short-term effects. Many…
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…
