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.
In a small, carefully controlled study, seven people with major depression each received a single low-dose ketamine infusion on one day and a saline infusion on another day, without anyone knowing which was which. People who got ketamine showed clear improvement in their depressive symptoms within three days, while those…
In a small, controlled study of 18 people with treatment-resistant major depression, a single intravenous dose of the NMDA receptor antagonist ketamine (0.5 mg/kg) produced rapid drops in depression scores. Improvement began within about 2 hours and remained statistically significant compared with placebo for up to 1 week. The study…
Researchers tested a nasal spray form of esketamine together with a newly started oral antidepressant in adults whose depression had not improved after trying at least two antidepressants. Over four weeks, people who got esketamine plus a new antidepressant had faster and larger drops in depression symptoms than those who…
This phase 3, double-blind trial tested whether continuing esketamine nasal spray plus an oral antidepressant could delay relapse in adults with treatment-resistant depression who had already improved after an initial esketamine course. Of 297 patients who entered the randomized phase, continuing esketamine reduced relapse compared with switching to placebo nasal…
Repeated ketamine infusions have cumulative and sustained antidepressant effects. Reductions in depressive symptoms were maintained among responders through once-weekly infusions. These findings provide novel data on efficacious administration strategies for ketamine in patients with treatment-resistant depression. Future studies should further expand on optimizing administration to better translate the use of…
This review looked at studies that measured cortisol (a stress hormone) after people visited forests, a practice called forest bathing or shinrin-yoku. The authors found that people in forest groups had lower salivary cortisol than people in urban groups, both before and after the visits. The reviewers say the change…
In a small, double-blind, placebo-controlled trial of Japanese adults aged 50–80 with mild cognitive impairment, 30 people were randomly assigned to take Yamabushitake (an edible mushroom) or placebo for 16 weeks. The mushroom group took four 250 mg tablets three times a day and showed higher scores on a cognitive…
This was a small, randomized, double-blind, placebo-controlled 13-week pilot trial of two nonpsychoactive cannabis-related compounds (cannabidiol, CBD, and tetrahydrocannabivarin, THCV) in 62 people with type 2 diabetes who were not using insulin. Participants were assigned to CBD, THCV, two CBD/THCV combination doses, or placebo. Compared with placebo, THCV lowered fasting…
Researchers gave 10 adults placebo cigarettes and three active marijuana cigarettes (including a 3.58% Delta9-THC dose) in a repeated-measures lab test. Using a task that forced a choice between a risky and a nonrisky option, the highest THC dose made people choose the risky option more often. The same high…
This small pilot randomized placebo‑controlled trial tested a cannabinoid spray (Sativex) in 30 adults with ADHD. The main test of cognition and activity (QbTest) showed no significant difference between Sativex and placebo in the intention‑to‑treat analysis (Estimate = -0.17, 95% CI -0.40 to 0.07, p = 0.16). Some secondary measures…
This study demonstrated that treatment with three infusions of ketamine was well tolerated in patients with alcohol use disorder and was associated with more days of abstinence from alcohol at 6-month follow-up. The findings suggest a possible beneficial effect of adding psychological therapy alongside ketamine treatment.
This was a single-blinded, randomized trial of 290 premenopausal women with unexplained fatigue and low iron who received one 1000 mg IV dose of ferric carboxymaltose (FCM) or saline placebo. By Day 56, more women given FCM had reduced fatigue and larger improvements in some quality-of-life and cognitive scores, and…
