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Tobias Buchborn

10 papers in the library · 227 citations · publishing 2016-2026

Papers

Positive expectations predict improved mental-health outcomes linked to psychedelic microdosing

Scientific Reports January 21, 2021 Laura Kaertner, Michael B. Steinborn, Hannes Kettner et al. 152 citations

A prospective study of weekly psychedelic microdosing found that participants reported improved well-being, emotional stability, and reduced anxiety and depressive symptoms over four weeks. However, baseline positive expectancy scores predicted these improvements, suggesting a significant placebo response. The findings caution against overinterpreting the therapeutic value of microdosing.

The ego in psychedelic drug action – ego defenses, ego boundaries, and the therapeutic role of regression

Frontiers in Neuroscience October 6, 2023 Tobias Buchborn, Hannes S. Kettner, Laura Kärtner et al. 21 citations

The ego is central to psychedelic research and therapy but remains poorly defined. This theoretical review examines the ego through a psychodynamic lens, focusing on ego boundaries, defenses, and synthesis. Psychedelics can induce regressed ego states with reduced defenses, allowing early-life conflicts that created maladaptive patterns to emerge. The authors argue that lasting change requires psycholytic therapy to permeate the characterological core—the chronic, habitual patterns the ego uses to cope—not just transient ego regression. Emotional integration of formative early events is key to reshaping rigid character and defenses, aiming for more flexible ego patterns. This approach is compatible with third-wave cognitive behavioral therapies.

Body mass index (BMI) does not predict responses to psilocybin

Journal of Psychopharmacology November 14, 2022 Meg J Spriggs, Bruna Giribaldi, Taylor Lyons et al. 15 citations

A fixed 25 mg dose of psilocybin produces similar acute psychedelic effects and improvements in well-being regardless of body mass index (BMI). Pooling data from three therapeutic studies, results support the null hypothesis that BMI does not predict overall intensity of the altered state, mystical experiences, perceptual changes, or emotional breakthroughs. There was weak evidence that lower BMI participants reported greater 'dread of ego dissolution,' but BMI did not meaningfully add to predictions beyond age, sex, and study. Mystical-type experiences and emotional breakthroughs strongly predicted well-being improvements, but BMI did not. These findings suggest body weight-adjusted dosing may be unnecessary, supporting fixed dosing to reduce practical and financial burdens on psychedelic therapy scalability.

The serotonin 2A receptor agonist 25CN-NBOH increases murine heart rate and neck-arterial blood flow in a temperature-dependent manner

Journal of Psychopharmacology February 12, 2020 Tobias Buchborn, Taylor Lyons, Chenchen Song et al. 11 citations

Activating serotonin 2A receptors with a highly selective agonist (N-(2-hydroxybenzyl)-2,5-dimethoxy-4-cyanophenylethylamine) increases heart rate and slightly elevates neck-arterial blood flow in anesthetized mice. Raising the heat-pad temperature from 37°C to 41°C enhanced the drug's effect on blood flow while counteracting the rapid heart rate. The drug also slowed breathing, which reversed at the higher temperature, and selectively increased core body temperature only under elevated pad conditions. Arterial oxygen saturation remained unchanged. These results suggest that selective serotonin 2A receptor activation links cardiovascular changes with thermoregulation, potentially influencing brain hemodynamics relevant to the psychedelic state.

Cortical Correlates of Psychedelic-Induced Shaking Behavior Revealed by Voltage Imaging

International Journal of Molecular Sciences May 30, 2023 Tobias Buchborn, Taylor Lyons, Chenchen Song et al. 6 citations

Shaking behavior—head twitches in mice and wet dog shakes in rats—is a reliable indicator of psychedelic drug action, thought to involve serotonin 2A receptors on cortical pyramidal cells, though direct evidence in living animals has been limited. Using cell type-specific voltage imaging in awake mice, researchers expressed a voltage indicator in layer 2/3 pyramidal neurons and captured cortical activity while mice displayed psychedelic shaking behavior. Shaking was preceded by high-frequency oscillations and overlapped with low-frequency oscillations in the motor cortex, spectrally mirroring the rhythm of the shakes. These findings reveal a cortical fingerprint of serotonin-2A-receptor-mediated shaking behavior, linking a cross-mammalian psychedelic effect to cell-type specific brain dynamics.

Lasting effect of psilocybin on sociability can be blocked by DNA methyltransferase inhibition

bioRxiv (Cold Spring Harbor Laboratory) March 11, 2025 Chenchen Song, Tinya Chang, Tobias Buchborn et al. 4 citations preprint

A single dose of the psychedelic psilocybin lastingly improves social behavior in a mouse model of autism (Cntnap2-knockout mice). This effect is blocked by inhibiting DNA methyltransferase I, suggesting an epigenetic mechanism involving DNA methylation underlies psilocybin's long-term influence on social function.

Exploring the Effects of Psilocybin on Depression and the Mediating Role of the 5-HT2A Receptor: A Systematic Review

Acta Neuropsychiatrica September 3, 2025 Filipe Reis Teodoro Andrade, Tobias Buchborn, Gabriel Thalheimer et al. 3 citations

Psilocybin therapy shows substantial and rapid antidepressant effects, often after one or two sessions with psychological support, with improvements sustained for weeks or months in many cases. It is generally well-tolerated, with mild adverse effects such as anxiety during administration and transient headaches that are manageable in controlled settings. Psilocybin demonstrates promise as a novel treatment for depression, especially for individuals unresponsive to conventional antidepressants. Further research is needed to refine dosing, explore long-term effects, and understand its mechanisms of action.

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

Visual hallucinations in Lewy body diseases (Parkinson's disease and dementia with Lewy bodies) and those induced by serotonergic psychedelics (psilocybin, mescaline) share overlapping phenomenology and neural mechanisms, despite different underlying causes. Both conditions produce visual aberrations from minor distortions to complex hallucinations, including illusory motion and entity encounters. Neuroimaging shows a common pattern of overactive associative cortex and underactive sensory cortex. Serotonin 2A receptor modulation is involved in both: psychedelics act through 5-HT2A and 5-HT1A receptors, while in Lewy body diseases, 5-HT2A receptor upregulation correlates with increased hallucinations, and blocking it with pimavanserin reduces them. Shared cortical signatures include reduced visual evoked responses and shifts toward visual excitation.

Oxa-noribogaine reduces alcohol drinking through aversion learning and by altering glutamatergic activity in the mPFC

Research Square March 31, 2026 Marcus W. Meinhardt, Ivan Skorodumov, Florian Walter et al.

A compound derived from ibogaine, oxa-noribogaine, reduces alcohol consumption in rats by strengthening learning from negative drinking outcomes. It produces sustained decreases in alcohol intake and relapse-like drinking, matching or exceeding ibogaine's efficacy without detectable motor or cardiac side effects. These effects involve transient changes in prefrontal brain activity, lasting alterations in glutamatergic signaling after aversion-related learning, and normalization of neurotrophic signaling in cortico-striatal circuits. The results generalize across multiple models, genetically diverse animals, and independent study sites, identifying oxa-noribogaine as a promising treatment candidate for alcohol use disorder.