Frontier mental health research: psychedelics & drug studies

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.

3 papers

Ketamine for Depression

Based on 34 papers

Research shows that ketamine and a related drug, esketamine, can lift depressive symptoms quickly for some people, especially those who did not get better with usual antidepressants. Short-term randomized trials and expert reviews report clear, often fast benefits after a single dose or a few doses, and esketamine (a nasal spray) is approved for some hard-to-treat depressions. At the same time, many studies are small or short. The fast benefit often fades after days to a few weeks, so patients commonly receive repeated treatments. Researchers still need better long-term safety data, clearer rules about dosing and maintenance, and more work to understand exactly how ketamine works in the human brain.

Key findings

  • Ketamine can reduce depressive symptoms very fast — often within hours or a day after a single infusion. 10149 10152 10151 15070
  • A nasal form called esketamine has been tested in trials and has faster symptom improvement when added to an oral antidepressant; it is approved for some treatment‑resistant cases. 12156 15070 10153
  • Effects after one dose often do not last long. Symptoms commonly start to return after about one to two weeks, so clinics use repeated dosing to try to keep benefits. 15070 10149 10159
  • The overall evidence comes from randomized controlled trials, several clinical trials, and expert reviews, but many studies are small or short, so long‑term safety and the best treatment schedules are still uncertain. 10153 15070 10152 10159
  • Common short‑term side effects include brief dissociation (strange or dreamlike feelings), temporary rises in blood pressure, dizziness, and headache; these effects usually pass within a few hours after treatment. 10159 10152 10151
  • When ketamine is given in medical settings, evidence so far shows few clear cases of addiction or dependence, but the data are limited and some cases of tolerance or dependence have been reported. 8828 10153
  • One randomized trial found ketamine was at least as effective as electroconvulsive therapy (ECT) for nonpsychotic, treatment‑resistant major depression, but this does not settle which treatment is best for every person. 10160 10149
  • Scientists think ketamine works by blocking NMDA receptors and then boosting other glutamate receptors (AMPA) and growth signals in the brain, but the exact pathways are still being worked out. 10146 10147 10148
  • Some biological markers are unclear: a meta‑analysis found no consistent change in blood BDNF (a growth protein) after psychoplastogen drugs like ketamine, which shows a gap between animal models and measurable human blood changes. 15129 10146
  • People with depression view ketamine as promising but worry about its reputation, long‑term harms, and how clinics would monitor use; patients also report that non‑drug factors (like what they saw or did before sessions) can shape their ketamine experiences. 12365 15075

Treatment‐resistant depression: definition, prevalence, detection, management, and investigational interventions

Roger S. McIntyre, Mohammad Alsuwaidan, Bernhard T. Baune, Michael Berk, Koen Demyttenaere, Joseph F. Goldberg, et al.
World Psychiatry Summary & key facts 2023 586 citations

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…

Electroconvulsive Therapy Studies Transcranial Magnetic Stimulation Studies Treatment of Major Depression Ketamine

Efficacy and safety of a 4-week course of repeated subcutaneous ketamine injections for treatment-resistant depression (KADS study): randomised double-blind active-controlled trial

Colleen Loo, Nick Glozier, Dávid Barton, Bernhard T. Baune, Natalie Mills, Paul B. Fitzgerald, et al.

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…

Mental Health Research Topics Treatment of Major Depression Tryptophan and brain disorders Ketamine

Psychedelic therapies reconsidered: compounds, clinical indications, and cautious optimism

Jennifer Mitchell, B. Anderson
Neuropsychopharmacology Summary & key facts 2023 44 citations

This review describes a rapid rise in medical research on psychedelic drugs over the past five years. Several later-stage clinical trials have been published, and many different drugs — including psilocybin, MDMA, ketamine, LSD, ayahuasca, and ibogaine — are being tested for conditions such as depression, post‑traumatic stress, addiction, obsessive‑compulsive…

Chemical synthesis and alkaloids Neurotransmitter Receptor Influence on Behavior Psychedelics and Drug Studies Ayahuasca Ibogaine
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