Major Depressive Disorder (MDD)Depressive DisordersAnxiety DisordersHeadache Disorders (Cluster & Migraine)Chronic PainLSD

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

This mice and cell study of the non-hallucinogenic LSD analogue 2-bromo-LSD (2-Br-LSD) found it to be a partial agonist at the 5-HT2A receptor but it doesn't activate the 5-HT2B receptor associated with cardiac valvulopathy (disease of heart valves). It also does not induce tolerance and has been shown to promote neuronal structural plasticity and active coping behaviour in mice. Additionally, 2-Br-LSD reverses the effects of chronic stress. These findings suggest that 2-Br-LSD may have therapeutic potential for mood disorders and other indications.

Authors

  • Yasmin Schmid
  • John McCorvy
  • Adam Halberstadt

Published

Cell Reports
individual Study

Abstract

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 mice, supporting its classification as a non-hallucinogenic 5-HT2A partial agonist. Unlike LSD, 2-Br-LSD lacks 5-HT2B agonism, an effect linked to cardiac valvulopathy. Additionally, 2-Br-LSD produces weak 5-HT2A β-arrestin recruitment and internalization in vitro and does not induce tolerance in vivo after repeated administration. 2-Br-LSD induces dendritogenesis and spinogenesis in cultured rat cortical neurons and increases active coping behavior in mice, an effect blocked by the 5-HT2A-selective antagonist volinanserin (M100907). 2-Br-LSD also reverses the behavioral effects of chronic stress. Overall, 2-Br-LSD has an improved pharmacological profile compared with LSD and may have profound therapeutic value for mood disorders and other indications.

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Research Summary of 'A non-hallucinogenic LSD analog with therapeutic potential for mood disorders'

Introduction

Current pharmacotherapies for major depressive disorder (MDD) and anxiety disorders carry well-recognised drawbacks, including delayed therapeutic onset, the requirement for chronic dosing, and substantial rates of treatment resistance. Growing clinical interest has therefore focused on serotonergic psychedelics such as psilocybin, DMT, and LSD, which have shown durable reductions in depression and anxiety after only one or two doses in placebo-controlled trials. Their therapeutic effects are largely attributed to activation of the serotonin 2A (5-HT2A) receptor, though whether these benefits depend on the subjective hallucinogenic experience or can be achieved independently remains an open question. The present study aimed to characterise 2-bromolysergic acid diethylamide (2-Br-LSD, also known as BOL-148), a structural analogue of LSD first synthesised by Albert Hofmann that does not induce hallucinogenic effects in humans. Preliminary evidence had suggested that 2-Br-LSD may retain therapeutic activity despite lacking psychedelic properties, including findings demonstrating efficacy against cluster headaches. Lewis and colleagues sought to determine whether 2-Br-LSD shares the antidepressant-relevant pharmacological and neuroplasticity-promoting properties of classical psychedelics whilst avoiding the hallucinogenic effects that complicate clinical use.

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