Scientific Reports
December 3, 2020
Theodoros Karapanagiotidis, Diego Vidaurre, Andrew J. Quinn et al.
82 citations
When people are not engaged in an explicit task, they experience a variety of self-generated thoughts, such as planning or reminiscing. Using machine learning to analyze brain activity from resting-state fMRI scans, researchers identified distinct neural states that recur over time. Two of these states predicted different patterns of thinking. One neural state, resembling activity seen during demanding tasks, was linked to problem-solving about the future. Another state, associated with less demanding conditions, was tied to intrusive thoughts about the past. These two states fell at opposite ends of a brain hierarchy related to cognitive demand. The findings show that tracking moment-to-moment changes in brain function can help classify self-generated mental states and that these states align with the brain's response to cognitive tasks.
Scientific Reports
May 26, 2016
Johannes G. Ramaekers, J. H. van Wel, Desirée Spronk et al.
81 citations
Acute cannabis intoxication impairs executive function, impulse control, attention, and psychomotor function, and increases subjective intoxication, regardless of how frequently a person uses cannabis. In a study of 122 drug users with cannabis use histories ranging from infrequent to daily, cannabis (300 μg/kg THC) produced these deficits compared to placebo, while cocaine (300 mg) improved psychomotor function and attention but impaired impulse control. The absence of tolerance to cannabis's neurocognitive effects suggests that frequent use and intoxication can interfere with performance in daily environments such as school, work, or traffic.
Scientific Reports
November 18, 2021
Joseph M. Rootman, Pamela Kryskow, Kalin Harvey et al.
78 citations
Among self-selected users of a mobile app, people who microdose psychedelics (mostly psilocybin, 85%) were similar demographically to non-microdosers but more often reported a history of mental health concerns. Within that group, microdosers had lower levels of depression, anxiety, and stress across genders. Health and wellness motives were the most common reasons for microdosing, especially among women and those with mental health concerns. The findings highlight a need for rigorous longitudinal research on microdosing's mental health effects.
Scientific Reports
November 3, 2017
Will Lawn, Jaime E. C. Hallak, José Alexandre S. Crippa et al.
78 citations
Ayahuasca users reported greater well-being than both classic psychedelic users and non-psychedelic drug users, and less problematic drinking than classic psychedelic users, though both psychedelic groups reported more problematic drinking than non-psychedelic users. Ayahuasca's acute subjective effects typically lasted six hours, peaking one hour after consumption. These findings come from a large online survey of nearly 97,000 respondents, including 527 ayahuasca users. The authors call for longitudinal studies and randomized trials to further investigate ayahuasca's effects on well-being and alcohol use.
Scientific Reports
December 6, 2018
Benjamin Baird, Anna Castelnovo, Olivia Gosseries et al.
74 citations
People who have frequent lucid dreams—three or more per week—show stronger functional connections between the left anterior prefrontal cortex and several brain regions, including the angular gyrus, middle temporal gyrus, and inferior frontal gyrus, compared to people who rarely or never lucid dream. These connections involve areas that are normally less active during sleep. No differences in brain structure were found. The findings suggest that frequent lucid dreaming is linked to how certain brain networks communicate, not to structural differences.
Scientific Reports
June 5, 2017
Ze-Min Xie, Xingming Wang, Ning Xu et al.
69 citations
Rats with neuropathic pain that also developed depression-like behaviors had higher levels of pro-inflammatory cytokines (interleukin-1β and interleukin-6) and an imbalance between pro- and anti-inflammatory cytokines, along with lower levels of brain-derived neurotrophic factor in the prefrontal cortex, compared to rats without depression-like behaviors and sham-operated controls. A single dose of ketamine reversed both the depression-like behaviors and the elevated serum levels of IL-1β and IL-6. These findings suggest that changes in inflammatory cytokines and BDNF may underlie depression caused by neuropathic pain, and that serum cytokines could serve as biomarkers for ketamine's antidepressant effects.
Scientific Reports
August 25, 2017
Gaël Chételat, Florence Mezenge, Clémence Tomadesso et al.
67 citations
Aging typically shrinks brain volume and lowers glucose metabolism, with stress and poor sleep accelerating these changes. In a pilot study comparing 6 elderly expert meditators with 67 elderly controls, the meditators showed greater gray matter volume and/or FDG metabolism in several brain regions: the ventromedial prefrontal and anterior cingulate cortex, insula, temporo-parietal junction, and posterior cingulate cortex/precuneus. These same regions were most affected by age in a larger control group of 186 people aged 20 to 87. The differences persisted after adjusting for lifestyle factors and education. The findings suggest that lifelong meditation might reduce age-related brain decline, but larger and longitudinal studies are needed.
Scientific Reports
May 24, 2022
David Wyndham Lawrence, Robin Carhart-Harris, Roland R. Griffiths et al.
64 citations
An analysis of over 3,700 naturalistic experiences with inhaled N,N-DMT posted to Reddit over a decade reveals common themes. Somatic effects like body sensations (37.5%) and auditory ringing (15.4%) were frequent, while visualizations often involved fractals, shapes, and vivid colors. Entity encounters occurred in 45.5% of experiences, most commonly with a feminine phenotype, deities, aliens, and creature-based beings. Interactions were predominantly positive or pedagogical. Descriptions of alternate dimensions, rooms including a 'waiting room,' and tunnels were common. Mystical and ego-dissolution features were frequent, along with rewarding aspects like reduced fear of death. Challenging responses were less common.
Scientific Reports
May 22, 2023
Teresa Fazia, Francesco Bubbico, Andrea Nova et al.
62 citations
A mindfulness-based program combining meditation, dietary advice, and yoga reduced stress and improved well-being, emotional regulation, resilience, and attention among medical students. In a randomized trial with 362 Italian medical students, those who participated in the 10-session intervention showed significantly lower perceived stress, less mind-wandering, and better emotional regulation compared to controls. The program also enhanced mental well-being, resilience, and attentional control, while reducing overall distress. These results suggest that such integrative interventions can help mitigate the psychological strain common in medical education.
Scientific Reports
October 20, 2020
Rubén Herzog, Pedro A. M. Mediano, Fernando E. Rosas et al.
60 citations
Psychedelic drugs such as lysergic acid diethylamide, which activate the serotonin 2A receptor, produce profound changes in consciousness and increase entropy in spontaneous neural activity. This study provides the first model-based explanation for that entropy increase by extending a whole-brain model of serotonergic neuromodulation. The model reproduced the overall entropy rise seen in previous experiments. Entropy changes were not uniform: some brain regions showed increased entropy while others showed decreases, indicating a topographical reconfiguration driven by receptor activation. At the whole-brain level, this reconfiguration was not well explained by receptor density but was closely related to the brain's anatomical connectivity topology.
Scientific Reports
August 5, 2016
Jaakko O. Nieminen, Olivia Gosseries, Marcello Massimini et al.
60 citations
During non-rapid eye movement (NREM) sleep, the brain's response to transcranial magnetic stimulation (TMS) differs depending on whether the person is conscious (dreaming) or not. When subjects reported no conscious experience upon awakening, TMS evoked a larger negative deflection and a shorter phase-locked response compared to when they reported a dream. The amplitude of the negative deflection—a hallmark of neuronal bistability—was inversely correlated with the length of the dream report. These findings suggest that variations in the level of consciousness within the same physiological state are associated with changes in underlying cortical bistability.
Scientific Reports
August 15, 2017
B. Martin, N. Franck, M. Cermolacce et al.
58 citations
People with schizophrenia struggle to predict when events will happen based on elapsed time, and this difficulty relates to disturbances in the sense of self. In a study of 28 patients and 24 matched controls, participants viewed a visual cue that either predicted or did not predict when a target would appear (after 400 ms or 1000 ms). Both groups responded faster to targets after longer intervals due to the natural predictability of time passing (the hazard function). However, patients with high scores on the EASE scale for self-awareness and presence showed no benefit from this temporal predictability, while those with low scores did.
Scientific Reports
October 3, 2019
Mario de la Fuente Revenga, Jong M. Shin, Hiba Vohra et al.
57 citations
A fully automated system detects head-twitch behavior (HTR) in mice, a behavioral marker of psychedelic drug action at the serotonin 5-HT2A receptor. The system was validated using the psychedelic DOI in mice lacking the 5-HT2A receptor and by evaluating false-positive and false-negative events. Automation enabled efficient time-course studies. Pharmacological interactions between the 5-HT2A receptor and metabotropic glutamate receptor 2 (mGluR2) were explored: the mGluR2/3 antagonist LY341495 potentiated DOI-induced HTR, while the mGluR2/3 agonist LY404039 blocked it. This system can accelerate understanding of 5-HT2A receptor pharmacology and its behavioral outputs in rodents.
Scientific Reports
April 17, 2024
Jordan Sloshower, Richard J. Zeifman, Jeffrey Guss et al.
56 citations
Psilocybin-assisted therapy improves psychological flexibility, mindfulness, and values-congruent living in people with moderate to severe major depressive disorder, and these improvements are strongly linked to reductions in depression severity. In an exploratory placebo-controlled study, participants received placebo then psilocybin (0.3 mg/kg) four weeks later, with dosing sessions embedded in Acceptance and Commitment Therapy. Psychological flexibility, several facets of mindfulness, and values-congruent living significantly improved after psilocybin and were maintained through week 16. The findings suggest that increasing psychological flexibility may be a key mechanism underlying psilocybin's therapeutic effects.
Scientific Reports
April 7, 2022
Grant Jones, Jocelyn A. Ricard, Joshua Lipson et al.
56 citations
People who have used psilocybin at some point in their lives have 30% lower odds of having opioid use disorder, based on data from a large U.S. national survey. No other classic psychedelic substances—such as LSD, peyote, or mescaline—showed a similar association. Psilocybin use was also linked to lower odds of meeting seven of the 11 diagnostic criteria for opioid use disorder. These findings suggest psilocybin may hold promise as a treatment, but clinical trials are needed to establish causality.
Scientific Reports
July 13, 2021
Otto Simonsson, Walter Osika, Robin Carhart-Harris et al.
54 citations
Lifetime use of classic psychedelics is associated with lower odds of heart disease and diabetes. Analyzing data from the National Survey on Drug Use and Health (2005–2014), people who had ever tried a classic psychedelic had 23% lower odds of past-year heart disease and 12% lower odds of past-year diabetes. The associations persisted after adjusting for other factors. The authors suggest classic psychedelic use might benefit cardiometabolic health but call for more research on causal pathways.
Scientific Reports
June 30, 2022
Joseph M. Rootman, Maggie Kiraga, Pamela Kryskow et al.
53 citations
A naturalistic observational study followed 953 people who microdosed psilocybin (taking small, non-hallucinogenic doses of psychedelic mushrooms) and 180 non-microdosers for about 30 days. Small to medium improvements in mood and mental health were observed among microdosers, consistent across gender, age, and pre-existing mental health concerns. Older adults showed specific improvements in psychomotor performance. Combining psilocybin with lion's mane mushrooms and niacin did not affect mood or mental health changes, but among older microdosers, this combination was linked to greater psychomotor improvements than psilocybin alone or with lion's mane. These findings add controlled evidence to the growing research on psychedelic microdosing.
Scientific Reports
October 2, 2020
Manoj K. Doss, Darrick G. May, Matthew W. Johnson et al.
52 citations
Salvinorin A, a κ-opioid receptor agonist and dissociative hallucinogen found in Salvia divinorum, alters human brain functional connectivity in ways similar to other hallucinogens. In a placebo-controlled, within-subject fMRI study, inhaled Salvinorin A tended to decrease functional connectivity within brain networks while increasing connectivity between networks, most notably attenuating the default mode network during peak effects. It reduced brainwide dynamic functional connectivity but increased brainwide entropic functional connectivity, though only the reduction survived statistical correction. Connectome-based classification models trained on dynamic connectivity accurately identified Salvinorin A scans, especially when using default mode network interactions. These findings suggest shared neural mechanisms across hallucinogen types.
Scientific Reports
April 17, 2023
Rubén Herzog, Pedro A. M. Mediano, Fernando E. Rosas et al.
51 citations
Psychedelic drugs such as LSD, which activate the serotonin 2A receptor, produce profound changes in consciousness and are linked to increased entropy in spontaneous brain activity. This study provides the first model-based explanation for that entropy increase by extending a whole-brain model of serotonin neuromodulation. The model reproduced the overall rise in neural entropy seen in prior experiments. Entropy increased across all brain regions, with the largest effects in visuo-occipital areas. At the whole-brain level, this reconfiguration was not well explained by the density of serotonin 2A receptors but was closely related to the topological properties of the brain's anatomical connectivity.
Scientific Reports
February 5, 2024
Alistair Niemeijer, Erwin Krediet, Jeanine Kamphuis et al.
50 citations
Patients with treatment-resistant depression who received psilocybin in a clinical trial described challenges with trust-building and expectation management, the need to navigate intense experiences often guided by music, and a desire for a more comprehensive treatment including multiple psilocybin sessions and sustained therapy. Distrust in mental healthcare generally, but trust in study therapists, was a key subtheme. The findings suggest that optimizing psilocybin treatment for this population requires individualized preparation, investment in trust-building, additional sessions, and access to ongoing psychotherapy with trusted therapists.
Scientific Reports
July 28, 2020
Qingqin S. Li, Ewa Wajs, Rachel Ochs-Ross et al.
49 citations
A genome-wide association study in 527 people of European ancestry with major depressive disorder identified a significant genetic locus in the IRAK3 gene and a significant gene-level association in NME7 linked to the antidepressant efficacy of esketamine nasal spray, measured as percentage change in symptom severity. Polygenic risk score analysis showed the strongest association with esketamine efficacy came from genetic loading for depressive symptoms, though this did not reach study-wide significance. Suggestive signals were enriched in pathways related to neuronal and synaptic function, immune signaling, and glucocorticoid receptor/stress response.
Scientific Reports
August 19, 2019
Cole Korponay, Daniela Dentico, Tammi R. A. Kral et al.
49 citations
An eight-week mindfulness intervention did not reduce impulsivity on the go/no-go task or Barratt Impulsiveness Scale (BIS-11), nor produce changes in neural correlates such as frontostriatal gray matter, functional connectivity, or dopamine levels compared to active or wait-list control groups. Long-term meditators (LTMs) did not differ from meditation-naïve participants (MNPs) on the go/no-go task, but LTMs self-reported lower attentional impulsivity and higher motor and non-planning impulsivity on the BIS-11. LTMs had less striatal gray matter, greater cortico-striatal-thalamic functional connectivity, and lower spontaneous eye-blink rate than MNPs. Total lifetime practice hours did not significantly relate to impulsivity or neurobiological metrics, suggesting pre-existing differences may account for group differences.
Scientific Reports
November 5, 2018
Matthieu Darracq, Chadd M. Funk, Daniel Polyakov et al.
49 citations
Sleep and anesthesia alter conscious experience, which can be absent (unconsciousness) or take the form of dreaming where sensory stimuli are not incorporated (disconnected consciousness). Using transcranial magnetic stimulation-electroencephalography over parietal regions, evoked alpha power (8-12 Hz) decreased during disconnected consciousness in rapid eye movement sleep and ketamine anesthesia compared to wakefulness. In unconscious states of propofol anesthesia and non-rapid eye movement sleep, evoked low-gamma power (30-40 Hz) decreased compared to wakefulness or disconnected consciousness. These findings, confirmed with dream reports from serial awakenings, suggest suppression of evoked alpha activity may mark sensory disconnection.
Scientific Reports
November 7, 2019
Meichao Zhang, Nicola Savill, Daniel S. Margulies et al.
48 citations
People often find their thoughts drifting away from the text they are reading, a tendency known as mind-wandering, which impairs comprehension and memory for the text. Using fMRI, the study found that individuals with poorer memory for texts show reduced activity in the left middle temporal gyrus in response to written input. This region sits at the intersection of the default mode, dorsal attention, and frontoparietal networks. In a resting-state analysis, stronger connectivity within the default mode network was associated with better text memory, while greater decoupling between the default mode network and medial visual regions was linked to more frequent mind-wandering. These results suggest that intrinsic brain network connectivity influences how attention stays engaged with reading.
Scientific Reports
October 10, 2022
Grant Jones, Matthew K. Nock
46 citations
Lifetime use of MDMA or psilocybin is associated with lower odds of psychological distress and suicidality among White individuals, but these protective associations are far fewer for racial and ethnic minorities. Analyzing data from over 484,000 participants in the National Survey on Drug Use and Health (2008–2019), race and ethnicity significantly moderated the links between psychedelic use and mental health outcomes. The findings highlight the need for further research on how identity factors such as race, ethnicity, socioeconomic status, and sexual/gender minority status influence the effects of psychedelic substances.