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Adam L. Halberstadt

University of California San Diego, VA San Diego Healthcare System

69 papers in the library · 4,004 citations · publishing 2008-2026

Papers

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Feasibility and Tolerability of Psilocybin for Phantom Limb Pain.

Journal of Pain August 1, 2026 Jon G. Dean, Ethan Hurwitz, T. Furnish et al.

Phantom limb pain (PLP) is a refractory condition defined by pain experienced in a missing limb. Psilocybin, a classical serotonergic psychedelic drug, can alleviate various treatment-resistant disorders but has scantly been investigated for chronic pain. This placebo-controlled, double-blind, randomized clinical pilot trial (NCT05224336) tested the feasibility, tolerability, and preliminary...

Evidence for pro-cognitive benefits of cannabinoids in people with bipolar disorder.

Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology July 21, 2026 Alannah Miranda, Breanna M Holloway, Elizabeth Peek et al.

Cannabis use is highly prevalent among people with bipolar disorder, potentially due to a desire to self-medicate against symptoms, such as racing thoughts and poor concentration. Such symptoms are associated with attention and inhibitory control deficits, functions that are regulated in-part by temporal perception. Temporal perception is impaired in BD and is slowed by acute cannabis exposure....

Differential Effects of Acute and Chronic Fluoxetine on Psychedelic-Induced Behavior in Mice: Implications for Clinical Trials.

ACS Pharmacology & Translational Science March 13, 2026 Bo Jarrett Wood, M Frances Vest, Catharine Carfagno et al.

Selective serotonin reuptake inhibitors (SSRIs) are widely prescribed for mood and anxiety disorders, the same conditions under which psychedelic-assisted therapies are gaining renewed interest. However, it remains unclear how SSRI treatment may influence sensitivity to psychedelics, particularly through the shared engagement of serotonergic pathways. Here, we used the head-twitch response...

Correction to "Next-Generation MDMA Analogue SDMA: Pharmacological and Metabolic Insights".

ACS Chem Neurosci March 4, 2026 Nina Kastner, Núria Nadal‐gratacós, Selina Hemmer et al. correction

Correction 1: Table 1.The analyses were conducted using the correct data, and all results, interpretations, and conclusions in the paper remain fully accurate.The issue is limited to the presentation of values in the table.Correction 2: p 4733, second paragraph, 1 st sentence.Thigmotaxis was evaluated to assess potential anxiety-like effects induced by the compounds.When comparing the tested...

Transforming Amino Acids into Serotonin 5-HT 2A Receptor Ligands Using Photochemistry

Journal of the American Chemical Society December 16, 2025 J.O.S. Beckett, Ryan Buzdygon, Steven Nguyen et al. 1 citation

A light-induced cyclization via a radical spin-center shift process that results in the direct functionalization of the indole ring at the C4-position is developed into a practical method for the synthesis of medicinally active, ring-constrained tryptamine analogs. Amino acids were coupled to tryptamine and irradiated with UV light to produce a library of lactams bridging the C3- and...

Next-Generation MDMA Analogue SDMA: Pharmacological and Metabolic Insights

ACS Chemical Neuroscience December 2, 2025 Nina Kastner, Núria Nadal‐gratacós, Selina Hemmer et al.

3,4-Methylenedioxymethamphetamine (MDMA), commonly known as ecstasy, shows promise in treating depression and post-traumatic stress disorder (PTSD), resulting in breakthrough status. However, concerns regarding MDMA's abuse potential and cytotoxicity have sparked interest in developing safer analogues with similar therapeutic benefits. This study investigated the pharmacological properties of...

Discovery of Highly Selective 5-HT2A Agonists Using Structure-Guided Design

Journal of Medicinal Chemistry September 25, 2025 Tyler G. Fenske, J. M. T. Mckee, Natalie G. Cavalco et al.

With a resurgence in interest in psychedelics as rapid-acting and durable neuroplastic therapies, there is a critical need to develop more selective 5-HT 2A agonists to investigate the basic neurobiological mechanisms of psychedelics. Here, we show that selectivity for 5-HT 2A over the closely related 5-HT 2C receptor can be leveraged using structure-based design to target residue L123 2.53 in...

Low (micro)doses of 2,5-dimethoxy-4-propylamphetamine (DOPR) increase effortful motivation in low-performing mice.

Neuropharmacology May 1, 2025 Michael Noback, Johnny A Kenton, Adam K. Klein et al. 2 citations

Treating amotivated states remains difficult. Classical psychedelic drugs (5-HT2A receptor agonists) such as LSD and psilocybin have shown therapeutic potential in treating such symptoms, but their development has been hindered by their undesirable hallucinogenic effects. There is increasing evidence that administration of psychedelics at dose levels too low to evoke a hallucinogenic effect...

Visual Hallucinations in Serotonergic Psychedelics and Lewy Body Diseases

Schizophrenia Bulletin April 17, 2025 Nathan H. Heller, Frederick S. Barrett, Tobias Buchborn et al. 3 citations

Abstract Background and Hypothesis Visual hallucinations (VH) are a core symptom of both Lewy body diseases (LBDs; eg, Parkinson’s disease and dementia with Lewy bodies) and serotonergic psychedelics (SPs; eg, psilocybin and mescaline). While these conditions differ in etiology, overlapping phenomenology, and neural mechanisms suggest shared pathways. This review explores similarities and...

Analytical and behavioral characterization of 1-hexanoyl-LSD (1H-LSD).

Drug Testing and Analysis April 1, 2025 Simon D. Brandt, Pierce V. Kavanagh, Sarah Gare et al. 4 citations

The development of lysergic acid diethylamide (LSD) derivatives and analogs continues to inform the design of novel receptor probes and potentially new medicines. On the other hand, a number of newly developed LSD derivatives have also emerged as recreational drugs, leading to reports of their detection in some countries. One position in the ergoline scaffold of LSD that is frequently targeted...

Analytical and behavioral characterization of 1-dodecanoyl-LSD (1DD-LSD).

Drug Testing and Analysis 2025 Pierce V. Kavanagh, Folker Westphal, Benedikt Pulver et al. 8 citations

1-Acetyl-N,N-diethyllysergamide (1A-LSD, ALD-52) was first synthesized in the 1950s and found to produce psychedelic effects similar to those of LSD. Evidence suggests that ALD-52 serves as a prodrug in vivo and hydrolysis to LSD is likely responsible for its activity. Extension of the N1-alkylcarbonyl chain gives rise to novel lysergamides, which spurred further investigations into their...

Analytical and Pharmacological Characterization of 1-(Furan-2-Carbonyl)-LSD (1F-LSD) and Comparison With 1-(Thiophene-2-Carbonyl)-LSD (1T-LSD).

Drug Testing and Analysis December 3, 2024 Simon D. Brandt, Pierce V. Kavanagh, Sarah Gare et al. 5 citations

The classical psychedelic drug (+)-lysergic acid diethylamide (LSD) continues to attract considerable multidisciplinary interest, and over the last eight decades, many derivatives and analogs of LSD have been synthesized. One site on the ergoline scaffold of LSD that has been frequently modified is the N1-position, with the N1-acylated LSD derivative 1-acetyl-LSD (1A-LSD, ALD-52) being one of...

Analytical and behavioral characterization of N-ethyl-N-isopropyllysergamide (EIPLA), an isomer of N6 -ethylnorlysergic acid N,N-diethylamide (ETH-LAD).

Drug Testing and Analysis February 1, 2024 Simon D. Brandt, Pierce V. Kavanagh, Folker Westphal et al. 5 citations

Preclinical investigations have shown that N-ethyl-N-isopropyllysergamide (EIPLA) exhibits lysergic acid diethylamide (LSD)-like properties, which suggests that it might show psychoactive effects in humans. EIPLA is also an isomer of N6 -ethylnorlysergic acid N,N-diethylamide (ETH-LAD), a lysergamide known to produce psychedelic effects in humans that emerged as a research chemical. EIPLA was...

Serotonin-2 Receptor Agonists Produce Anti-inflammatory Effects through Functionally Selective Mechanisms That Involve the Suppression of Disease-Induced Arginase 1 Expression

ACS Pharmacology & Translational Science January 25, 2024 Thomas W. Flanagan, Timothy P. Foster, Thomas E. Galbato et al. 18 citations

Functional selectivity in the context of serotonin 2A (5-HT 2A ) receptor agonists is often described as differences psychedelic compounds have in the activation of Gq vs β-arrestin signaling in the brain and how that may relate to inducing psychoactive and hallucinatory properties with respect to each other. However, the presence of 5-HT 2A receptors throughout the body in several cell types,...

Identification of 5-HT2A receptor signaling pathways associated with psychedelic potential.

Nat Commun December 15, 2023 Jason Wallach, Andrew B. Cao, Maggie M. Calkins et al. 153 citations

Abstract Serotonergic psychedelics possess considerable therapeutic potential. Although 5-HT 2A receptor activation mediates psychedelic effects, prototypical psychedelics activate both 5-HT 2A -Gq/11 and β-arrestin2 transducers, making their respective roles unclear. To elucidate this, we develop a series of 5-HT 2A -selective ligands with varying Gq efficacies, including β-arrestin-biased...

Identification of 5-HT 2A Receptor Signaling Pathways Responsible for Psychedelic Potential

bioRxiv (Cold Spring Harbor Laboratory) July 31, 2023 Jason Wallach, Andrew B. Cao, Maggie M. Calkins et al. 11 citations preprint

Summary Serotonergic psychedelics possess considerable therapeutic potential. Although 5-HT 2A receptor activation mediates psychedelic effects, prototypical psychedelics activate both 5-HT 2A -Gq/11 and β-arrestin2 signaling, making their respective roles unclear. To elucidate this, we developed a series of 5-HT 2A -selective ligands with varying Gq efficacies, including β-arrestin-biased...

A non-hallucinogenic LSD analog with therapeutic potential for mood disorders.

Cell Reports March 28, 2023 Vern Lewis, Emma M. Bonniwell, Janelle K. Lanham et al. 129 citations

Hallucinations limit widespread therapeutic use of psychedelics as rapidly acting antidepressants. Here we profiled the non-hallucinogenic lysergic acid diethylamide (LSD) analog 2-bromo-LSD (2-Br-LSD) at more than 33 aminergic G protein-coupled receptors (GPCRs). 2-Br-LSD shows partial agonism at several aminergic GPCRs, including 5-HT2A, and does not induce the head-twitch response (HTR) in...

Analytical profile of the lysergamide 1cP-AL-LAD and detection of impurities.

Drug Testing and Analysis March 1, 2023 Pierce V. Kavanagh, Folker Westphal, Benedikt Pulver et al. 7 citations

The development of novel lysergamides continues to occur, based on both the needs of psychedelic medicine and commercial interest in new recreational substances. The present study continues the authors' research on novel lysergamides and describes the analytical profile of 1-cyclopropanoyl-AL-LAD (IUPAC name:...

Use of the head-twitch response to investigate the structure–activity relationships of 4-thio-substituted 2,5-dimethoxyphenylalkylamines

Psychopharmacology December 7, 2022 Adam L. Halberstadt, Dino Luethi, Marius C. Hoener et al. 7 citations

Abstract Rationale 4-Thio-substituted phenylalkylamines such as 2,5-dimethoxy-4-ethylthiophenethylamine (2C-T-2) and 2,5-dimethoxy-4- n -propylthiophenethylamine (2C-T-7) produce psychedelic effects in humans and have been distributed as recreational drugs. Objectives The present studies were conducted to examine the structure–activity relationships (SAR) of a series of 4-thio-substituted...

Analytical profile, in vitro metabolism and behavioral properties of the lysergamide 1P‐AL‐LAD

Drug Testing and Analysis May 7, 2022 Simon D. Brandt, Pierce V. Kavanagh, Folker Westphal et al. 14 citations

Abstract Lysergic acid diethylamide (LSD) is known to induce powerful psychoactive effects in humans, which cemented its status as an important tool for clinical research. A range of analogues and derivatives has been investigated over the years, including those classified as new psychoactive substances. This study presents the characterization of the novel lysergamide N , N...

(2-Aminopropyl)benzo[β]thiophenes (APBTs) are novel monoamine transporter ligands that lack stimulant effects but display psychedelic-like activity in mice.

Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology March 1, 2022 Deborah Rudin, John D. Mccorvy, Grant C. Glatfelter et al. 18 citations

Derivatives of (2-aminopropyl)indole (API) and (2-aminopropyl)benzofuran (APB) are new psychoactive substances which produce stimulant effects in vivo. (2-Aminopropyl)benzo[β]thiophene (APBT) is a novel sulfur-based analog of API and APB that has not been pharmacologically characterized. In the current study, we assessed the pharmacological effects of six APBT positional isomers in vitro, and...

Return of the lysergamides. Part VII: Analytical and behavioural characterization of 1‐valeroyl‐d‐lysergic acid diethylamide (1V‐LSD)

Drug Testing and Analysis November 27, 2021 Simon D. Brandt, Pierce V. Kavanagh, Folker Westphal et al. 19 citations

Abstract The psychopharmacological properties of the psychedelic drug lysergic acid diethylamide (LSD) have attracted the interest of several generations of scientists. While further explorations involving novel LSD‐type compounds are needed to assess their potential as medicinal drugs, the emergence of novel derivatives as recreational drugs has also been observed. 1‐Valeroyl‐LSD (also known...

HIV Transgenic Rats Demonstrate Impaired Sensorimotor Gating But Are Insensitive to Cannabinoid (Δ9-Tetrahydrocannabinol)-Induced Deficits.

The International Journal of Neuropsychopharmacology November 12, 2021 Benjamin Z Roberts, Arpi Minassian, Adam L. Halberstadt et al.

HIV-associated neurocognitive disorder (HAND) is commonly observed in persons living with HIV (PWH) and is characterized by cognitive deficits implicating disruptions of fronto-striatal neurocircuitry. Such circuitry is also susceptible to alteration by cannabis and other drugs of abuse. PWH use cannabis at much higher rates than the general population, thus prioritizing the characterization of...

Chemoenzymatic Synthesis of 5-Methylpsilocybin: A Tryptamine with Potential Psychedelic Activity

Journal of Natural Products March 5, 2021 Janis Fricke, Alexander M. Sherwood, Adam L. Halberstadt et al. 18 citations

A novel analogue of psilocybin was produced by hybrid chemoenzymatic synthesis in sufficient quantity to enable bioassay. Utilizing purified 4-hydroxytryptamine kinase from Psilocybe cubensis, chemically synthesized 5-methylpsilocin (2) was enzymatically phosphorylated to provide 5-methylpsilocybin (1). The zwitterionic product was isolated from the enzymatic step with high purity utilizing a...

Investigation of the Structure–Activity Relationships of Psilocybin Analogues

ACS Pharmacology & Translational Science December 14, 2020 Adam K. Klein, Muhammad Chatha, Lauren J. Laskowski et al. 103 citations

The 5-HT2A receptor is thought to be the primary target for psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine) and other serotonergic hallucinogens (psychedelic drugs). Although a large amount of experimental work has been conducted to characterize the pharmacology of psilocybin and its dephosphorylated metabolite psilocin (4-hydroxy-N,N-dimethyltryptamine), there has been little systematic...