Biological Psychiatry Cognitive Neuroscience and Neuroimaging
April 29, 2022
Mihai Avram, Felix Müller, Helena Rogg et al.
43 citations
Psychedelics, empathogens, and psychostimulants produce increased connectivity between the thalamus and sensorimotor areas of the brain, a pattern similar to that observed in individuals with psychotic disorders. This suggests a shared neural mechanism across these substances and certain psychiatric conditions, linking altered thalamocortical communication to changes in perception and behavior.
Frontiers in Psychiatry
October 13, 2021
Mihai Avram, Helena Rogg, Αλεξάνδρα Κορδά et al.
43 citations
Classic psychedelics and acute psychosis share overlapping disruptions in brain connectivity, particularly involving the thalamus and its connections to cortical regions. Both states exhibit hyperconnectivity between the thalamus and sensorimotor cortices, linked to altered perceptions and hallucinations. Psychosis also shows hypoconnectivity between the thalamus and prefrontal cortices, associated with cognitive disturbances. These patterns of thalamocortical dysconnectivity extend to cortico-striato-pallido-thalamo-cortical circuitry. The review synthesizes neuroimaging and neuropharmacological evidence to highlight shared and distinct neurophysiological changes, suggesting clinically relevant parallels that may inform future research on perception and cognition.
Molecular psychiatry
April 1, 2025
Mihai Avram, Lydia Fortea, Lea Wollner et al.
26 citations
Lysergic acid diethylamide (LSD), d-amphetamine, and MDMA each reduce the integrity (within-network connectivity) of several brain networks, with LSD uniquely reducing integrity in the default-mode network. Contrary to expectations, amphetamines reduced integrity in more networks than LSD. LSD produced more pronounced decreases in between-network segregation, while amphetamines also induced increases. Seed-based connectivity mostly increased between networks across all substances, with LSD showing stronger effects than both amphetamines. All substances decreased global connectivity in visual areas, but LSD specifically increased global connectivity in the basal ganglia and thalamus. These findings clarify distinctive neurobiological effects of psychedelics and support further investigation of their therapeutic potential.
Biological psychiatry. Cognitive neuroscience and neuroimaging
May 1, 2024
Mihai Avram, Felix Müller, Katrin H Preller et al.
13 citations
In a double-blind, placebo-controlled, crossover study with 25 healthy participants, LSD, MDMA, and d-amphetamine all increased effective connectivity from the thalamus to specific unimodal cortices while reducing the influence of those cortices back onto the thalamus, indicating stronger bottom-up and weaker top-down information flow. For transmodal cortices, including parts of the salience network, amphetamines showed opposite effects. LSD uniquely increased effective connectivity from the thalamus to both unimodal and transmodal cortices, suggesting a breakdown in the hierarchical organization of brain activity. These findings refine models of how psychedelics alter brain connectivity.
Cell Reports Medicine
May 7, 2026
Mihai Avram, Aurore Menegaux, Felix Müller et al.
1 citation
Lysergic acid diethylamide (LSD) may alleviate depression by altering white matter microstructure in the brain, potentially reflecting enhanced neuroplasticity. In a clinical trial of 61 patients with major depressive disorder, those receiving moderate-to-high doses (100 μg then 200 μg) showed increased fractional anisotropy in several white matter tracts, including the internal and external capsule, sagittal stratum, and fornix/stria terminalis. These microstructural changes correlated with improvements in depressive symptoms measured at 2, 6, and 12 weeks. The findings suggest that LSD-induced white matter changes are linked to antidepressant effects.
Psychedelics as Psychiatric Medications
March 1, 2023
Mihai Avram, Felix Müller, Stefan Borgwardt
1 citation
Lysergic acid diethylamide (LSD) is a potent perception-altering chemical that has been both revered and demonized since its discovery. Before its ban in the late 1960s, it was used to model aspects of psychosis and treat alcohol addiction and anxiety. Recent clinical trials show LSD can be administered safely in clinical settings to healthy volunteers and clinical groups. Small studies suggest potential therapeutic uses for anxiety. LSD's perception-altering effects involve agonism at the 5-HT2A receptor. Neuroimaging reveals LSD enhances signal diversity and complexity, decreases resting-state connectivity within intrinsic brain networks, and increases between-network connectivity, including thalamocortical connectivity.
Fortschritte der Neurologie · Psychiatrie
April 1, 2024
Stefan Borgwardt, Tomislav Majić, Mihai Avram et al.
Classic psychedelics such as psilocybin, LSD, ayahuasca, and 5-MeO-DMT are attracting renewed psychiatric, psychotherapeutic, and neuroscientific interest, driven by recent clinical trials suggesting therapeutic benefits for treatment-resistant depression, substance use disorders, anxiety disorders, and existential distress in life-threatening physical illness. Despite these promising effects, the substances carry unique risks due to the phenomenology of their central nervous system effects, the temporal dynamics of their psychological impacts, and their biological action profile, distinguishing them from many other psychoactive drugs.
medRxiv
Klemens Egger, Daniel Meling, Firuze Polat et al.
preprint
In a double-blind, placebo-controlled pharmaco-fMRI study, 40 meditation practitioners on a three-day retreat received either placebo or buccal DMT-harmine (120 mg each). Meditation alone increased network segregation across several resting-state networks, while DMT-harmine increased functional connectivity within the visual network and between visual and attention networks. Between-group differences showed increased connectivity between visual and salience networks in the DMT-harmine group. No prolonged cortical gradient disruption was observed, indicating a return to typical brain organization shortly after the experience. Meditation reduced connectivity between networks, whereas DMT-harmine increased within- and between-network connectivity, revealing distinct neural mechanisms.