International Journal of Neuropsychopharmacology
September 9, 2026
O Syed, F Alam, P Giacobbe
Abstract Background Major depressive disorder (MDD) is a debilitating medical condition that places a significant psychological, social, and financial burden on the individuals and families of those affected. However, a third of individuals with MDD do not respond to standard treatments – diagnosed with treatment-resistant depression (TRD). Repeated dosing of intravenous (IV) ketamine has...
CNS Drugs
July 1, 2026
Omer A. Syed, Valentyn Sobolenko, Sean M. Nestor et al.
Background and Objective Ketamine and esketamine have emerged as effective and rapid-acting interventions for treatment-resistant depression. Nevertheless, the best-suited candidates for these treatments are not clear. As such, the ability to personalize treatment selection and parameters would likely improve therapeutic response. This systematic review synthesized the literature on clinical...
BJPsych Open
May 13, 2026
Zeina Beidas, Anya Ragnhildstveit, Adam Blackman et al.
Microdosing psilocybin for major depressive disorder: study protocol for a phase II double-blind placebo-controlled randomised partial crossover trial - CORRIGENDUM.
Research Square
February 23, 2026
Rotem Petranker, Norman A. S. Farb, Omer A. Syed et al.
Abstract IMPORTANCE Microdosing psilocybin may be a novel treatment for major depressive disorder (MDD). OBJECTIVE Assessing the antidepressant effects and safety of repeated low doses of psilocybin in participants diagnosed with MDD. DESIGN This was a Phase II, randomized, double-blind, placebo-controlled clinical trial. SETTING The trial was conducted from July 2022 to December 2024 at two...
BJPsych Open
February 16, 2026
Zeina Beidas, Anya Ragnhildstveit, Adam Blackman et al.
1 citation
BACKGROUND: Major depressive disorder (MDD) is the leading cause of disability worldwide, affecting roughly 322 million people. Recently, doses of psilocybin have shown promise in treating mood disorders, sparking interest in other dosing practices. According to anecdotal reports and observational studies, microdosing psilocybin yields benefits to mental health; however, rigorously controlled...
Neuroscience & Biobehavioral Reviews
January 24, 2026
Omer A. Syed, Benjamin Tsang, Sean M. Nestor et al.
Psilocybin-assisted therapy (PAT) is an emerging intervention for depression. Though several clinical trials report promising results for PAT in treating depression, there remains a need for consensus on optimal methodologies and standardization of PAT protocols. The objective of this review was to assess the efficacy of PAT in treating depressive symptoms and to systematically examine the...
Psychiatry Research
December 29, 2025
Omer A. Syed, Sean M. Nestor, Muhammad Ishrat Husain et al.
1 citation
Psychedelic use has greatly increased within clinical and recreational settings over recent years. While demonstrating a favorable safety profile within certain clinical populations, little empirical research has explored safety of psychedelic use within real-world samples. Using the World Health Organization (WHO) VigiBase, a comprehensive global pharmacovigilance database with voluntary...
November 16, 2025
Zeina Beidas, Anya Ragnhildstveit, Adam Blackman et al.
preprint
Background: Major depressive disorder (MDD) is the leading cause of disability worldwide, affecting roughly 322 million people. Recently, doses of psilocybin have shown promise in treating mood disorders, sparking interest in other dosing practices. According to anecdotal reports and observational studies, microdosing psilocybin yields benefits to mental health; however, rigorously controlled...
Neuroscience & Biobehavioral Reviews
May 9, 2025
Rotem Petranker, Benjamin Tsang, Omer A. Syed
3 citations
Microdosing, the repeated use of psychedelic substances at low doses, is growing in popularity among recreational consumers. While this practice is associated with many benefits to mood, well-being and health, research in this area is in its early stages and predominantly centered on human applications. In this narrative review, we synthesize the findings from studies investigating the effects...
Journal of Psychoactive Drugs
December 24, 2024
Omer A. Syed, Rotem Petranker, Emily C. Fewster et al.
3 citations
Although several studies have well described the characteristics of people who use psychedelics alongside their motivations and beliefs, little research has examined the preferences surrounding the source of psychedelic substances. In an anonymous online survey, we collected data from 6,379 consumers of 11 different psychedelic substances from 85 different countries, exploring their preferences...
Journal of Psychoactive Drugs
November 6, 2024
Rotem Petranker, Valentyn Sobolenko, Zeina Beidas et al.
9 citations
Despite psychedelic microdosing being a growing practice, the research on the topic is still in its infancy. While several studies have described the characteristics, motivations and practices of microdosers, the differences between individuals that only microdose and those that use both micro and macrodoses of psychedelics remain unexplored. In an online survey, we collected data of 6193...
npj Mental Health Research
November 8, 2023
Omer A. Syed, Benjamin Tsang
4 citations
The recent years have seen an unprecedented surge of psychedelic research. Studies with psilocybin (colloquially known as magic mushrooms), in particular, have shown promise in ameliorating symptoms of treatment-refractory depression, anxiety, and substance use disorder, among others 1 , 2 . Microdosing, the practice of regularly taking roughly a tenth of full psychedelic doses, is becoming...
Neuroscience and Biobehavioral Reviews
October 1, 2023
Omer A. Syed, Benjamin Tsang, Robert Gerlai
7 citations
In this review, we discuss the possible utility of zebrafish in research on psilocybin, a psychedelic drug whose recreational use as well as possible clinical application are gaining increasing interest. First, we review behavioral tests with zebrafish, focussing on anxiety and social behavior, which have particular relevance in the context of psilocybin research. Next, we briefly consider...