Maastricht University

The Impact of Psilocybin on Pain in Fibromyalgia Patients (PsiloFM)

Start Date

April 1, 2024

Compounds

Psilocybin, Placebo

The Effect of LSD on Neural Synchrony, Prosocial Behavior, and Relationship Quality

Start Date

January 1, 2023

Compounds

LSD, Placebo

Sub(acute) Profiling of 2C-B Versus Psilocybin

Start Date

August 4, 2021

Compounds

2C-X, Psilocybin, Placebo

Acute and delayed effects of MDMA intoxication on false memories in a legal context

Start Date

November 3, 2017

Compounds

MDMA, Placebo

MDMA and prosocial behavior: The role of the 2a-serotonin receptor

Start Date

January 30, 2013

Compounds

MDMA, Placebo

The role of the 5-HT2a receptor in MDMA-induced effects on social cognition and prosocial behaviour

Start Date

January 23, 2013

Compounds

MDMA, Placebo

Personality and Drug Use (PDU)

Start Date

November 1, 2022

Subjective and neurocognitive profiling of clinical doses of 3,4-methylenedioxymethamphetamine (MDMA) in healthy volunteers: implications for therapeutic use

This narrative review (2026) examines placebo-controlled single-dose studies of MDMA (75 to 125 mg) in healthy volunteers and finds that it acutely increases mood, empathy, trust and prosocial feelings, while causing temporary memory impairment and modest declines in motor coordination and cognitive flexibility. It also notes that post-acute fatigue and low mood can occur, and that MDMA may complicate trial blinding and expectancy in psychotherapy studies.

Published

April 8, 2026

Journal

Molecular Psychiatry

Authors

Ramaekers, J. G., Kuypers, K. P. C., Vollenweider, F. X.

The forgotten psychedelic: Spatiotemporal mapping of brain organisation following the administration of 2C-B and psilocybin

Using 7T resting-state fMRI in a double-blind, placebo-controlled crossover study, the authors show that acute 2C-B and psilocybin both reduce intra-network static connectivity while increasing between-network and subcortical–cortical coupling and brain complexity, but 2C-B causes less between-network desynchronisation and relative elevations in transmodal connectivity compared with psilocybin. These spatially divergent effects align with monoaminergic transporter and serotonergic receptor distributions and link transmodal-axis desynchronisation to behavioural measures, highlighting 2C-B as a distinct tool for psychedelic neuroscience and potential pharmacotherapies.

Published

February 3, 2026

Journal

Molecular Psychiatry

Authors

Mallaroni, P., Singleton, P., Mason, N. L., Satterthwaite, T. D., Ramaekers, J. G.

Shared functional connectome fingerprints following ritualistic ayahuasca intake

This fMRI study (n=21) of people who regularly use ayahuasca within the Santo Daime church finds that during the experience, changes in functional connectivity (FC, how brain areas communicate) indicate on the scans more similarity between them (so less 'unique' FC). The authors use an analogy that each person still has their own hairstyle, but instead of wearing different coloured t-shirts, all are now wearing the same shirt.

Published

January 1, 2024

Journal

NeuroImage

Authors

Mallaroni, P., Mason, N. L., Kloft, L., Reckweg, J. T., Van Oorsouw, K., Toennes, S. W., Tolle, H. M., Amico, E., Ramaekers, J. G.

Assessment of the acute effects of 2C-B vs psilocybin on subjective experience, mood and cognition

In a within‑subjects, double‑blind, placebo‑controlled study (n=22) of psychedelic‑experienced volunteers, 20 mg 2C‑B produced acute psychedelic alterations of moderate experiential depth but elicited less dysphoria, subjective impairment, auditory changes and ego‑dissolution than 15 mg psilocybin. Both drugs produced comparable psychomotor slowing, spatial memory impairments and transient pressor effects, while 2C‑B’s subjective effects were shorter in duration (largely resolving within ~6 hours).

Published

June 11, 2023

Journal

Clinical Pharmacology and Therapeutics

Authors

Mallaroni, P., Mason, N. L., Reckweg, J. T., Paci, R., Toennes, S. W., Theunissen, E. L., Kuypers, K. P. C., Ramaekers, J. G.