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.

12 papers

Lack of energy or motivation

Based on 24 papers

Researchers are testing many ways to help people who feel low energy or low motivation, often as part of treating depression. The clearest, strongest evidence right now is for ketamine and its close relative esketamine. These drugs can reduce depressive symptoms quickly for some people who did not get better with usual medicines. Regular physical activity, especially walking, also has good evidence for reducing depressive symptoms and may help energy over time. Other approaches look promising but are still early-stage. Psychedelic-assisted psychotherapy (drugs like psilocybin or MDMA given together with careful therapy) shows encouraging results in trials but needs more research and detailed therapy support. Brain-based treatments such as deep brain stimulation (DBS) or combining brain stimulation with ketamine are experimental but may help some people who have not responded to many other treatments. Whole-body hyperthermia (controlled heating) is very preliminary and needs careful testing and safety checks. Across all options, safety, careful preparation, and close follow-up are important because effects and risks vary between people.

Key findings

  • Ketamine and esketamine can reduce depressive symptoms quickly, sometimes within hours to days, and they have the strongest clinical evidence among rapid-acting treatments. 15070 10153 10149 10152
  • Esketamine nasal spray, when added to a newly started oral antidepressant, produced faster and larger drops in depression scores over four weeks in a randomized trial. 12156
  • Ketamine treatments commonly cause short-lived side effects such as dissociation (strange or dream-like feelings) and temporary blood pressure rises, so dosing and monitoring are important. 10159 10149 10153
  • Psychedelic-assisted psychotherapy (for example psilocybin or MDMA given inside a therapy program) shows encouraging results for some people with hard-to-treat depression and PTSD, but the evidence is still early and responses vary a lot between individuals. 15063 15053 15070
  • Good preparation and careful support before and after drug sessions (called 'set and setting' and integration work) are widely considered important for safety and for getting the most benefit in psychedelic-assisted therapy. 15065
  • Regular physical activity, including structured exercise programs and walking, has medium-sized benefits for lowering depressive symptoms and may help energy and motivation over time. 8792 8785 8788
  • Deep brain stimulation produced strong responses in a small trial of people with very treatment-resistant depression, but this evidence comes from a small number of patients and is still experimental. 10166
  • Combining brain stimulation (transcranial magnetic stimulation) with ketamine is a promising idea that might boost and lengthen benefits, but current evidence is preliminary and more trials are needed. 10162
  • Whole-body hyperthermia (controlled heating) can raise protective heat-shock proteins and may improve mitochondrial (cell energy) function, but its use for brain symptoms is experimental and requires precise dosing and careful monitoring. 15128
  • Many standard antidepressants cause weight gain for many people, which can affect health and treatment decisions; bupropion is an antidepressant that is less likely to cause weight gain and is sometimes linked to weight loss. 15114

Antidepressant Efficacy of Ketamine in Treatment-Resistant Major Depression: A Two-Site Randomized Controlled Trial

James W. Murrough, Dan V. Iosifescu, Lee C. Chang, Rayan K. Al Jurdi, Charles E. Green, Andrew M. Perez, et al.
American Journal of Psychiatry Summary & key facts 2013 1,186 citations

Researchers tested a single intravenous dose of ketamine in 73 people with major depression that had not gotten better with usual treatments. In a two-site, double-blind trial, people were randomly given either ketamine or an active placebo (the anesthetic midazolam). Twenty-four hours after the infusion, people who got ketamine were…

Neuroscience and Neuropharmacology Research Treatment of Major Depression Tryptophan and brain disorders Ketamine

Efficacy and Safety of Flexibly Dosed Esketamine Nasal Spray Combined With a Newly Initiated Oral Antidepressant in Treatment-Resistant Depression: A Randomized Double-Blind Active-Controlled Study

Vanina Popova, Ella Daly, Madhukar H. Trivedi, Kimberly Cooper, Rosanne Lane, Pilar Lim, et al.
American Journal of Psychiatry Summary & key facts 2019 839 citations

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…

Anxiety, Depression, Psychometrics, Treatment, Cognitive Processes Treatment of Major Depression Tryptophan and brain disorders Ketamine

Synthesizing the Evidence for Ketamine and Esketamine in Treatment-Resistant Depression: An International Expert Opinion on the Available Evidence and Implementation

Roger S. McIntyre, Joshua D. Rosenblat, Charles B. Nemeroff, Gerard Sanacora, James W. Murrough, Michael Berk, et al.
American Journal of Psychiatry Summary & key facts 2021 646 citations

A group of international mood-disorder experts reviewed the research on ketamine and esketamine for adults whose depression did not get better with usual antidepressants. They found that these drugs work differently from standard antidepressants and can lift symptoms more quickly for some people with treatment-resistant depression. However, the experts also…

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

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

Management of Treatment-Resistant Depression: Challenges and Strategies

Daphne Voineskos, Zafiris J. Daskalakis, Daniel M. Blumberger

This paper is a careful review of research about treatment-resistant depression. The authors looked through medical studies to see how doctors define this kind of depression, what makes it hard to assess, and which treatments have been tried. They describe drug strategies like adding lithium or thyroid hormone, switching antidepressant…

Electroconvulsive Therapy Studies Treatment of Major Depression Tryptophan and brain disorders Ketamine Psilocybin

Canadian Network for Mood and Anxiety Treatments (CANMAT) 2023 Update on Clinical Guidelines for Management of Major Depressive Disorder in Adults: Réseau canadien pour les traitements de l’humeur et de l’anxiété (CANMAT) 2023 : Mise à jour des lignes directrices cliniques pour la prise en charge du trouble dépressif majeur chez les adultes

Raymond W. Lam, Sidney H. Kennedy, G. Camelia Adams, Anees Bahji, Serge Beaulieu, Venkat Bhat, et al.

The CANMAT 2023 update gives doctors clear, up-to-date advice for treating adults with major depressive disorder. It puts evidence into a practical, clinician-friendly format. The update says treatment should be a team effort between patients and clinicians, be tailored to each person, and follow a planned, systematic process with regular…

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

Ketamine and rapid antidepressant action: new treatments and novel synaptic signaling mechanisms

John H. Krystal, Ege T. Kavalali, Lisa M. Monteggia
Neuropsychopharmacology Summary & key facts 2023 188 citations

This review explains how ketamine can lift depression symptoms much faster than standard antidepressants. Researchers describe the clinical results, how doctors usually give ketamine, and the brain changes it seems to cause. They also say that the treatment must be given carefully because small dose changes matter, the exact brain…

Neuroscience and Neuropharmacology Research Treatment of Major Depression Tryptophan and brain disorders 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

Ketamine and serotonergic psychedelics: An update on the mechanisms and biosignatures underlying rapid-acting antidepressant treatment

Jenessa N. Johnston, Bashkim Kadriu, Josh Allen, Jessica R. Gilbert, Ioline D. Henter, Carlos A. Zarate
Neuropharmacology Summary & key facts 2023 59 citations

This paper reviews what scientists know about how ketamine and classic serotonergic psychedelics (like psilocybin and LSD) can lift depression quickly. The authors compare how the drugs work in the brain, point out that ketamine has the strongest clinical evidence so far, and say psychedelics show early promise but need…

Neurotransmitter Receptor Influence on Behavior Psychedelics and Drug Studies Tryptophan and brain disorders Ketamine LSD

Uncovering the Underlying Mechanisms of Ketamine as a Novel Antidepressant

Songbai Xu, Xiaoxiao Yao, Bingjin Li, Ranji Cui, Cuilin Zhu, Yao Wang, et al.
Frontiers in Pharmacology Summary & key facts 2022 50 citations

Major depressive disorder is a serious illness. Researchers reviewed how ketamine — a drug that blocks a brain receptor called the NMDA receptor — can lift depression symptoms quickly and for a sustained time in people and in animals. They describe possible ways ketamine works: it may boost another type…

Neuroscience and Neuropharmacology Research Treatment of Major Depression Tryptophan and brain disorders Ketamine

RETRACTED ARTICLE: ArticleNoteRapid and sustained antidepressant effects of intravenous ketamine in treatment-resistant major depressive disorder and suicidal ideation: a randomized clinical trial

Ahmad Zolghadriha, Afagh Anjomshoaa, Mohammad Jamshidi, Farnaz Taherkhani
BMC Psychiatry Summary & key facts 2024 20 citations

This paper reported a small, randomized trial of 64 people with treatment-resistant major depression who were given a single intravenous dose of ketamine or a saline placebo. The authors said depression and suicidal thoughts dropped quickly — within an hour — and that benefits lasted up to two months, but…

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

Impact of Antidepressants on Weight Gain: Underlying Mechanisms and Mitigation Strategies

Michael Mouawad, Leena Nabipur, Devendra K Agrawal

This paper reviewed past studies to figure out why many people gain weight while taking antidepressants and what can be done about it. The authors found that about 55–65% of people on long-term antidepressants can gain weight, that different drugs carry different risks, and that the weight changes come from…

Diet and metabolism studies Pharmacology and Obesity Treatment Treatment of Major Depression
Summaries and links are for general information and education only. They are not a substitute for reading the original publication or for professional medical, legal, or other advice. Always refer to the linked source for the full study.