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Omer A. Syed

14 papers in the library · 28 citations · publishing 2023-2026

Papers

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Real-World Therapeutic Use of Ketamine in Clinical and Non-Clinical Settings: A Cross-Sectional Survey

Journal of Psychoactive Drugs September 23, 2026 Omer A. Syed, Rotem Petranker, Sean M. Nestor et al.

The use of ketamine as a treatment for mood disorders continues to grow in popularity. However, the differences between individuals consuming ketamine within clinical settings and those self-medicating in casual, non-clinical settings has not been yet characterized. Using the 2023 Global Psychedelic Survey, this study aimed to examine the demographic and clinical characteristics, as well as the...

47. Early improvement predicts subsequent antidepressant response to intravenous ketamine

The International Journal of Neuropsychopharmacology September 9, 2026 Omer A. Syed, Fahad Alam, Peter 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...

Clinical Predictors of Antidepressant Effects of Ketamine and Esketamine in Treatment-Resistant Unipolar and Bipolar Depression: A Systematic Review

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...

Safety and Efficacy of Microdosing Psilocybin over 8 Weeks for Major Depressive Disorder: A Randomized Clinical Trial

Research Square February 23, 2026 Rotem Petranker, Norman A. S. Farb, Omer A. Syed et al. preprint

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...

Microdosing psilocybin for major depressive disorder: study protocol for a phase II double-blind placebo-controlled randomised partial crossover trial

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...

Methodological moderators of psilocybin-assisted therapy in depression: A systematic review and meta-analysis

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...

Adverse events associated with classic psychedelics and MDMA: a real-world population-based study using the WHO pharmacovigilance database (VigiBase)

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...

Microdosing Psilocybin for Major Depressive Disorder: Study Protocol for a Phase II Double-Blind Placebo-Controlled Randomized Partial Crossover Trial

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...

The effect of psychedelic microdosing on animal behavior: A review with recommendations for the field

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...

Preferences, Perceptions, and Environmental Considerations of Natural and Synthetic Psychedelic Substances: Findings from the Global Psychedelic Survey

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...

DOI: 10.1080/02791072.2024.2446445 (opens in new tab) Environmental considerations Natural sources Psychedelics Synthetic substances +3

Global Trends in Psychedelic Microdosing: Demographics, Substance Testing Behavior, and Patterns of Use

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...

Managing expectations with psychedelic microdosing

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...

DOI: 10.1038/s44184-023-00044-9 (opens in new tab) Full text (opens in new tab) Recreational use Mental health Applied psychology Psychotherapist

The zebrafish for preclinical psilocybin research.

Neuroscience & 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...

A perspective on psychedelic teratogenicity: the utility of Zebrafish models.

TIPS - Trends in Pharmacological Sciences August 1, 2023 Omer A. Syed, Benjamin Tsang, Rotem Petranker et al.

Psychedelic drugs have experienced an unprecedented surge in recreational use within the past few years. Among recreational users, the risks of psychedelic use by pregnant and breastfeeding women are severely understudied and there is little information on the potential teratogenic effects of these drugs. We provide an overview of the previous data on psychedelic teratogenicity from rodent...