ACS Pharmacology & Translational Science
August 2, 2023
Zarmeen Zahid, Zhen Zheng, N. Jones et al.
50 citations
Psilocybin reduces anxiety-like behavior in male mice four hours after treatment, an effect that depends on a temporary spike in the stress hormone corticosterone. Blocking the corticosterone rise or the glucocorticoid receptor eliminated the short-term anxiolytic effect. A nonpsychedelic drug that also raised corticosterone produced similar anxiety reduction, as did stress-induced hormone release alone. The anxiolytic effect lasted seven days after a single psilocybin dose, but this long-term benefit was lost in mice with chronically elevated corticosterone. The findings suggest that an acute, resolvable glucocorticoid surge is necessary for psilocybin's postacute anxiety relief, while chronic stress hormone elevation undermines its lasting effects.
Molecular Biology of the Cell
May 27, 2021
Matthew I. Banks, Zarmeen Zahid, N. Jones et al.
37 citations
Psychedelics may promote neural plasticity, which is thought to underlie their therapeutic effects in psychiatric disorders. The drugs activate signaling pathways that can produce long-term structural changes in the brain, though these mechanisms are complex and not yet fully understood. Stress and inflammation also play roles in both acute and long-term effects. Beyond altering brain structure, psychedelics challenge and expand understanding of the neural basis of psychiatric disorders, consciousness, and human behavior.
bioRxiv (Cold Spring Harbor Laboratory)
August 14, 2020
N. Jones, Zarmeen Zahid, Sean M. Grady et al.
9 citations
preprint
Acute release of the stress hormone corticosterone modifies the lasting behavioral effects of psilocybin in male mice. Psilocybin caused an initial anxiety-like response and a rise in plasma corticosterone, followed by a later reduction in anxiety in the novelty suppressed feeding test. Both the acute and delayed effects disappeared when mice were first given chronic oral corticosterone to suppress their own stress-axis. One week later, psilocybin-treated mice spent more time in the center of an open field, but this long-term anxiolytic effect was also blocked by prior chronic corticosterone exposure. Brief isoflurane anesthesia after psilocybin eliminated these interactions. The findings identify glucocorticoid release as a biological modifier of psilocybin's post-acute and long-term behavioral effects in mice.
Trends in Cognitive Sciences
August 18, 2025
Flora Moujaes, Nathalie M. Rieser, L. Belinger et al.
5 citations
Serotonergic psychedelics are being investigated as treatments for psychiatric conditions, with promising results in mood disorders suggesting their effects on emotional processing may be central to therapeutic potential. However, mechanistic and clinical studies reveal a complex picture of how psychedelics impact emotions and mood. This review covers recent findings on psychedelics' effects on emotion, emotional empathy, and mood, discussing their influence on long-term emotion management strategies, the role of challenging experiences, and neuroplastic changes. The authors argue that more precise characterization of emotional states and attention to temporal dynamics of psychedelic-induced effects are critical for clarifying mechanisms and optimizing therapeutic impact.
Psychedelic medicine (New Rochelle, N.Y.)
September 1, 2024
Zarmeen Zahid, Ziyad W Sultan, Bryan M Krause et al.
5 citations
In mice, the serotonergic psychedelic DOI, but not ketamine, enhanced neural plasticity and metaplasticity in the hippocampus 24 hours after a single dose. Brain slices from DOI-treated animals showed stronger synaptic responses and short-term potentiation compared to saline-treated controls, with evidence that these effects involve a presynaptic mechanism. Ketamine did not produce similar changes. These findings suggest that the therapeutic benefits of serotonergic psychedelics may be supported by a window of heightened neural plasticity, whereas ketamine's effects may rely on different mechanisms.
AJNR. American journal of neuroradiology
June 3, 2025
Paloma C Frautschi, Ajay P Singh, Nicholas A Stowe et al.
2 citations
Psilocybin treatment in male mice led to structural connectivity differences in the frontal association cortex after 72 hours and microstructural changes in the primary visual cortex after 24 hours, as well as in the striatum and hippocampus after 72 hours, including increased mean diffusivity and decreased neurite density. These findings suggest that diffusion microstructure imaging can detect and characterize brain changes induced by psilocybin, offering a potential method to monitor treatment response and identify clinical endpoints for patients with major depressive disorder.
Journal of Pharmacology and Experimental Therapeutics
May 13, 2024
N. Jones, John A. Razidlo, Zarmeen Zahid et al.
1 citation
No Summary
Journal of psychopharmacology (Oxford, England)
May 2, 2026
Zarmeen Zahid, Rick J Strassman, Clifford R Qualls et al.
Blocking the 5-HT1A receptor with pindolol before giving a low dose of DMT to experienced hallucinogen users intensified the drug's subjective effects, with a moderate effect size. Blood pressure also increased shortly after DMT administration, while heart rate was unchanged. The findings suggest that 5-HT1A receptor activity normally dampens the subjective effects of psychedelics, pointing to a functional role for this receptor in shaping the psychedelic experience.
medRxiv Preprint Server
April 28, 2026
Sandeep M. Nayak, Nathan D. Sepeda, Matthew Nielsen Dick et al.
preprint
Psilocybin is being studied as a treatment for psychiatric and neurologic conditions, but there is limited comprehensive data on its cardiovascular safety. Current clinical trials typically exclude people with blood pressure of 140/90 mmHg or higher, a cutoff set conservatively without strong empirical evidence.