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.

72 papers

The Worldwide Prevalence of ADHD: A Systematic Review and Metaregression Analysis

Guilherme V. Polanczyk, Maurício Silva de Lima, Bernardo Lessa Horta, Joseph Biederman, Luís Augusto Rohde
American Journal of Psychiatry Summary & key facts 2007 5,230 citations

Our findings suggest that geographic location plays a limited role in the reasons for the large variability of ADHD/HD prevalence estimates worldwide. Instead, this variability seems to be explained primarily by the methodological characteristics of studies.

Attention Deficit Hyperactivity Disorder Cognitive Abilities and Testing

Taming THC: potential cannabis synergy and phytocannabinoid‐terpenoid entourage effects

Ethan B. Russo
British Journal of Pharmacology Summary & key facts 2011 1,481 citations

Some research suggests that whole-plant cannabis compounds (like THC, CBD, other cannabinoids, terpenes, and flavonoids) can interact so the plant’s effects differ from CBD alone. Healthline explains three CBD types — full-spectrum, broad-spectrum, and isolate — and notes legal, safety, and labeling limits. The article says there is evidence for…

Biochemical Analysis and Sensing Techniques Cannabis and Cannabinoid Research GABA and Rice Research

An Introduction to the Endogenous Cannabinoid System

Hui‐Chen Lu, Ken Mackie
Biological Psychiatry Summary & key facts 2015 1,165 citations

The endocannabinoid system (ECS) is a widespread brain signaling system made of cannabinoid receptors, naturally made lipid messengers, and the enzymes that make and break those messengers. The two best-studied messengers are 2-AG and anandamide, and they are produced and degraded by different enzyme pathways. CB1 receptors are common in…

Cannabis and Cannabinoid Research Neuroscience and Neuropharmacology Research Neurotransmitter Receptor Influence on Behavior

The serotonin theory of depression: a systematic umbrella review of the evidence

Moncrieff, Joanna, Cooper, Ruth E., Stockmann, Tom, et al.
Nature Summary & key facts 2023 830 citations

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…

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

Antioxidative and Anti-Inflammatory Properties of Cannabidiol

Sinemyiz Atalay, Iwona Jarocka-Karpowicz, Elźbieta Skrzydlewska
Antioxidants Summary & key facts 2019 765 citations

This review says cannabidiol (CBD) is a non‑psychoactive cannabis compound that has antioxidant and anti‑inflammatory actions in lab and some clinical studies. CBD can act directly to neutralize reactive molecules and indirectly by changing cell signals and antioxidant enzymes. Experiments in cells and animals show CBD lowers markers of oxidative…

Cannabis and Cannabinoid Research Diet, Metabolism, and Disease GABA and Rice Research

Review of the Endocannabinoid System

Hui‐Chen Lu, Ken Mackie

This review describes the endocannabinoid system (ECS) as a widespread network of natural cannabinoids, cannabinoid receptors (mainly CB1 and CB2), and the enzymes that make and break those chemicals. The ECS helps shape brain development and adjusts how neurons communicate. The authors note that THC is the main psychoactive part…

Cannabis and Cannabinoid Research Neuroscience and Neuropharmacology Research Neurotransmitter Receptor Influence on Behavior

Hepcidin—a regulator of intestinal iron absorption and iron recycling by macrophages

Tomas Ganz

Hepcidin is a small hormone made in the liver that helps control how the body absorbs and moves iron. It lowers iron flow into the blood by blocking ferroportin, the only known iron exporter on intestinal cells, macrophages (immune cells), and liver cells. Hepcidin levels rise when iron is high…

Hemoglobinopathies and Related Disorders Iron Metabolism and Disorders Trace Elements in Health

Chemistry, Nutrition, and Health-Promoting Properties of Hericium erinaceus (Lion’s Mane) Mushroom Fruiting Bodies and Mycelia and Their Bioactive Compounds

Mendel Friedman

This paper is a 2015 review that brings together many studies about the lion’s mane mushroom (Hericium erinaceus). It describes the mushroom’s chemical makeup, nutrients, food uses, and about 70 identified bioactive compounds. The review reports many claimed health effects seen in cell, animal, and some human studies—such as anti-inflammatory…

Fungal Biology and Applications Medicinal Plants and Bioactive Compounds Polysaccharides and Plant Cell Walls

Cannabidiol exerts sebostatic and antiinflammatory effects on human sebocytes

Attila Oláh, Balázs István Tóth, István Borbíró, Koji Sugawara, Attila Gábor Szöllősi, Gabriella Czifra, et al.

This laboratory study found that cannabidiol (CBD), a non‑psychoactive compound from Cannabis sativa, reduced fat production and inflammation in human sebaceous (oil) gland cells. The effects were seen in cultured human sebocytes and in human skin organ cultures, where CBD blocked the fat‑making (lipogenic) actions of several compounds. These results…

Biochemical Analysis and Sensing Techniques Cannabis and Cannabinoid Research Ion Channels and Receptors

Fatigue and Human Performance: An Updated Framework

Martin Behrens, Martin Gube, Hélmi Chaabène, Olaf Prieske, Alexandre Zénon, Kim‐Charline Broscheid, et al.
Sports Medicine Summary & key facts 2022 249 citations

This narrative review updates an earlier fatigue framework and proposes a clearer way to think about fatigue during tasks. It defines motor or cognitive task-induced state fatigue as a psychophysiological condition that can show up as a drop in performance and/or a stronger feeling of tiredness. The authors add cognitive…

Heart Rate Variability and Autonomic Control Occupational Health and Performance Sleep and Work-Related Fatigue

Effects of forest bathing (shinrin-yoku) on levels of cortisol as a stress biomarker: a systematic review and meta-analysis

Michele Antonelli, Grazia Barbieri, Davide Donelli

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…

Acupuncture Treatment Research Studies Biofield Effects and Biophysics Stress Responses and Cortisol

Cingulate dynamics track depression recovery with deep brain stimulation

Sankaraleengam Alagapan, Ki Sueng Choi, Stephen Heisig, Patricio Riva‐Posse, Andrea Crowell, Vineet Tiruvadi, et al.
Nature Summary & key facts 2023 233 citations

Researchers tested deep brain stimulation (DBS) in a small group of people whose depression did not get better with usual treatments. They used an implanted device that both delivered stimulation to the subcallosal cingulate (a brain area linked to mood) and recorded brain electrical signals. Around 9 out of 10…

Functional Brain Connectivity Studies Neurological disorders and treatments Transcranial Magnetic Stimulation Studies
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