Scientific Reports
April 19, 2017
Michael Schartner, Robin Carhart‐Harris, Adam B. Barrett et al.
450 citations
Measures of neural signal diversity, such as entropy and Lempel-Ziv complexity, are higher during wakeful rest than during anesthesia. In this study, these measures were computed for spontaneous magnetoencephalographic signals from humans under psilocybin, ketamine, and LSD. All three psychedelics produced reliably higher signal diversity, even after controlling for spectral changes, with the most pronounced increase in temporal (single-channel LZ complexity) rather than spatial diversity. Selective correlations emerged between changes in signal diversity and the intensity of psychedelic experience. This is the first time these measures have been applied to the psychedelic state and have yielded values exceeding normal waking consciousness, suggesting that psychedelic phenomenology constitutes an elevated level of consciousness.
Scientific Reports
October 25, 2017
Liila Taruffi, Corinna Pehrs, Stavros Skouras et al.
177 citations
Listening to sad music, compared with happy music, leads people to withdraw attention inward and engage in more mind-wandering—spontaneous, self-referential thought. Three experiments using probe-caught thought sampling and fMRI showed that sad music was associated with stronger mind-wandering and greater centrality of nodes in the Default Mode Network (DMN). The findings demonstrate that DMN activity can be modulated by the emotional valence of music, suggesting that sad music promotes internally directed cognition. These results have implications for using music in education and clinical settings to influence thought patterns.
Scientific Reports
July 7, 2017
José Á. Morales-García, Mario de la Fuente Revenga, Sandra Alonso‐gil et al.
173 citations
The three main alkaloids of Banisteriopsis caapi—harmine, tetrahydroharmine, and harmaline—along with the harmine metabolite harmol, stimulate adult neurogenesis in vitro. In neurospheres from adult mouse brain progenitor cells, all compounds increased neural stem cell proliferation, migration, and differentiation into adult neurons. This suggests that modulation of brain plasticity may contribute to the antidepressant effects of ayahuasca and expands potential applications of these alkaloids to other brain disorders benefiting from stimulation of endogenous neural precursor niches.
Scientific Reports
November 24, 2020
Julane Andries, Lisa Jerome, Evan Sola et al.
170 citations
A randomized controlled trial tested MDMA-assisted psychotherapy for anxiety in people with life-threatening illnesses. Participants received either MDMA (125 mg) or placebo during two 8-hour psychotherapy sessions. At one month after the second session, the MDMA group showed a greater average reduction in anxiety scores (23.5 points) compared to the placebo group (8.8 points), but the difference did not reach statistical significance. The treatment was well tolerated. After the trial, all participants received open-label MDMA sessions. These preliminary results suggest MDMA-assisted psychotherapy may be a promising approach, but larger trials are needed to confirm its effectiveness.
Scientific Reports
August 1, 2017
Aline Viol, Fernanda Palhano-Fontes, Heloisa Onias et al.
154 citations
The entropic brain hypothesis suggests that psychedelic experiences arise from increased randomness in the brain's functional connectivity. Analyzing resting-state fMRI data from human subjects before and after ingesting ayahuasca, a psychedelic beverage used in Amazonian religious and scientific contexts, researchers found that the Shannon entropy of the brain's degree distribution increased, indicating greater disorder in network connections. Local integration within brain networks increased while global integration decreased. These findings align with the entropic brain hypothesis and relate to users' reports of 'mind-expansion.'
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.
Scientific Reports
November 22, 2019
Isaac N. Treves, Lawrence Y. Tello, Richard J. Davidson et al.
118 citations
A meta-analysis of 15 studies (17 samples, 879 adults) found a small positive relationship between mindfulness and the accuracy of body awareness, with an effect size of g = 0.21. When analyzed by study design, only randomized controlled trials showed a significant link (g = 0.20). Heterogeneity was low, but low fail-safe N estimates reduce confidence in the findings. The results suggest a small but potentially detectable association between mindfulness and body awareness accuracy.
Scientific Reports
March 5, 2020
José Carlos Bouso, Daniel Jiménez‐garrido, María de Lourdes Gómez-sousa et al.
111 citations
Ayahuasca, a hallucinogenic decoction used in traditional Amazonian medicine, may have therapeutic benefits for psychiatric disorders. In a study of 40 first-time users, nearly half (45%) initially met criteria for a psychiatric disorder; after ayahuasca use, more than 80% of those showed clinical improvements that persisted at 6 months. Questionnaires indicated significant reductions in depression and psychopathology. Long-term users (n=23) had lower depression scores and higher self-transcendence and quality of life compared to first-time users. The authors suggest further controlled and observational studies are warranted to assess risks and benefits.
Scientific Reports
November 16, 2017
111 citations
The Hallucination Machine combines deep convolutional neural networks with panoramic virtual reality to simulate visual hallucinatory experiences without drugs or psychosis. In one experiment, the system induced visual phenomenology similar to classical psychedelics. In a second experiment, the simulated hallucinations did not produce the temporal distortion typically linked to altered states. This tool allows researchers to study altered consciousness without the confounding physiological and cognitive effects of psychoactive substances or psychopathological conditions.
Scientific Reports
September 25, 2023
Rebecka Bremler, Nancy Katati, Parvinder Shergill et al.
102 citations
Negative psychological responses to psychedelics lasting more than 72 hours are real and can include new psychiatric diagnoses or worsened symptoms. In a sample of 32 individuals who completed an online questionnaire, 37.5% received a new psychiatric diagnosis after their psychedelic experience, and 87% experienced anxiety symptoms. Deeper interviews with 15 of the most severe cases revealed potential causes: unsafe environments, unpleasant acute experiences, prior psychological vulnerabilities, high or unknown drug doses, and young age. The findings cannot estimate how common such harms are due to the small, selective sample and study design focused only on negative outcomes.
Scientific Reports
September 5, 2021
Ramona M. Rodriguiz, Vineet Nadkarni, Christopher R. Means et al.
92 citations
Lysergic acid diethylamide (LSD) produces psychedelic effects through the 5-HT2A serotonin receptor, which activates both Gq and β-arrestin signaling pathways. Using mice lacking either β-arrestin1 or β-arrestin2, researchers found that LSD stimulated motor activities and psychedelic-like behaviors—including head twitches, grooming, retrograde walking, and nose-poking—in normal mice and those missing β-arrestin1, but not in mice missing β-arrestin2. The 5-HT2A antagonist MDL100907 blocked these effects. LSD also disrupted prepulse inhibition in normal and β-arrestin1-knockout mice, but not in β-arrestin2-knockouts. These findings indicate that LSD's psychedelic actions require β-arrestin2 signaling.
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
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 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 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
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 1, 2024
Jonathan N. Davies, Anna Faschinger, Julieta Galante et al.
45 citations
Between 2002 and 2022, the use of meditation, yoga, and guided imagery or progressive relaxation among US adults rose significantly. By 2022, 18.3% (60.53 million) practiced meditation, 16.8% (55.78 million) practiced yoga, and 6.7% (22.22 million) used guided imagery or progressive relaxation. Growth was widespread across sociodemographic groups, but people of 'Other' race (54% Indigenous Americans) and those with moderate psychological distress were overrepresented across all practices. Individuals with severe distress were more likely to use meditation and guided imagery or progressive relaxation. Meditation use accelerated among adults aged 65 and older, those not accessing mental health care, and less educated groups, suggesting unmet health needs.
Scientific Reports
July 26, 2022
Caroline T. Golden, Paul Chadderton
45 citations
Psilocybin, a hallucinogenic compound being investigated for treating depression and PTSD, alters neural activity in the anterior cingulate cortex of awake mice. Using multi-unit recordings, the study found that psilocybin (2 mg/kg) significantly decreased low-frequency local field potential power while gamma activity trended upward. Overall population firing rates increased, with nearly half of individual neurons showing a significant increase. Psilocybin reduced phase modulation of cells across most frequency bands, indicating desynchronization of cortical populations. Bursting behavior changed in a subset of cells, and neurons that increased burst firing often transitioned from a phase-modulated to an unmodulated state. These effects suggest disruption of top-down processing and dissolution of the default mode network in the acute psychedelic state.
Scientific Reports
May 30, 2022
David R. Glowacki, Rhoslyn Roebuck Williams, Mark Wonnacott et al.
44 citations
A virtual reality framework called Isness-distributed (Isness-D) enables groups of people in a shared virtual space to experience their bodies as luminous energetic essences with diffuse boundaries, allowing moments of 'energetic coalescence' where bodies fluidly merge and participants include multiple others within their self-representation. In a citizen science study with 58 participants across an international network of Isness-D nodes, scores on four self-report scales (inclusion of community in self, ego-dissolution inventory, communitas scale, and MEQ30 mystical experience questionnaire) were statistically indistinguishable from those reported in recent psychedelic drug studies. This demonstrates that distributed VR can design intersubjective self-transcendent experiences where people dissolve their sense of self in connection to others.