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Psychology

The effects of psilocybin and MDMA on between-network resting state functional connectivity in healthy volunteers

May 27, 2014 / MDMA, Mushrooms / Psilocybin, Neuroscience, Papers, Psychology, Publications / By / , , , ,

Abstract

Perturbing a system and observing the consequences is a classic scientific strategy for understanding a phenomenon. Psychedelic drugs perturb consciousness in a marked and novel way and thus are powerful tools for studying its mechanisms. In the present analysis, we measured changes in resting-state functional connectivity (RSFC) between a standard template of different independent components analysis (ICA)-derived resting state networks (RSNs) under the influence of two different psychoactive drugs, the stimulant/psychedelic hybrid, MDMA, and the classic psychedelic, psilocybin. Both were given in placebo-controlled designs and produced marked subjective effects, although reports of more profound changes in consciousness were given after psilocybin. Between-network RSFC was generally increased under psilocybin, implying that networks become less differentiated from each other in the psychedelic state. Decreased RSFC between visual and sensorimotor RSNs was also observed. MDMA had a notably less marked effect on between-network RSFC, implying that the extensive changes observed under psilocybin may be exclusive to classic psychedelic drugs and related to their especially profound effects on consciousness. The novel analytical approach applied here may be applied to other altered states of consciousness to improve our characterization of different conscious states and ultimately advance our understanding of the brain mechanisms underlying them.

Roseman, L., Leech, R., Feilding, A., Nutt, D. J., & Carhart-Harris, R. L. (2014). The effects of psilocybin and MDMA on between-network resting state functional connectivity in healthy volunteers. Frontiers in Human Neuroscience, 8, 1-11. http://dx.doi.org/10.3389/fnhum.2014.00204
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Repeated lysergic acid diethylamide in an animal model of depression: Normalisation of learning behaviour and hippocampal serotonin 5-HT2 signalling

April 30, 2014 / Depressive Disorders, LSD, Neuroscience, Papers, Psychology, Publications / By / , , ,

Abstract

A re-balance of postsynaptic serotonin (5-HT) receptor signalling, with an increase in 5-HT1A and a decrease in 5-HT2A signalling, is a final common pathway multiple antidepressants share. Given that the 5-HT1A/2A agonist lysergic acid diethylamide (LSD), when repeatedly applied, selectively downregulates 5-HT2A, but not 5-HT1A receptors, one might expect LSD to similarly re-balance the postsynaptic 5-HT signalling. Challenging this idea, we use an animal model of depression specifically responding to repeated antidepressant treatment (olfactory bulbectomy), and test the antidepressant-like properties of repeated LSD treatment (0.13 mg/kg/d, 11 d). In line with former findings, we observe that bulbectomised rats show marked deficits in active avoidance learning. These deficits, similarly as we earlier noted with imipramine, are largely reversed by repeated LSD administration. Additionally, bulbectomised rats exhibit distinct anomalies of monoamine receptor signalling in hippocampus and/or frontal cortex; from these, only the hippocampal decrease in 5-HT2 related [35S]-GTP-gamma-S binding is normalised by LSD. Importantly, the sham-operated rats do not profit from LSD, and exhibit reduced hippocampal 5-HT2 signalling. As behavioural deficits after bulbectomy respond to agents classified as antidepressants only, we conclude that the effect of LSD in this model can be considered antidepressant-like, and discuss it in terms of a re-balance of hippocampal 5-HT2/5-HT1A signalling.

Buchborn, T., Schröder, H., Höllt, V., & Grecksch, G. (2014). Repeated lysergic acid diethylamide in an animal model of depression: Normalisation of learning behaviour and hippocampal serotonin 5-HT2 signalling. Journal of Psychopharmacology, 28(6), 545-552. https://dx.doi.org/10.1177/0269881114531666
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Psilocybin-Induced Decrease in Amygdala Reactivity Correlates with Enhanced Positive Mood in Healthy Volunteers

April 26, 2014 / Depressive Disorders, Mushrooms / Psilocybin, Neuroscience, Papers, Psychology, Publications / By / , , , , , ,

Abstract

Background
The amygdala is a key structure in serotonergic emotion-processing circuits. In healthy volunteers, acute administration of the serotonin 1A/2A/2C receptor agonist psilocybin reduces neural responses to negative stimuli and induces mood changes toward positive states. However, it is little-known whether psilocybin reduces amygdala reactivity to negative stimuli and whether any change in amygdala reactivity is related to mood change.

Methods
This study assessed the effects of acute administration of the hallucinogen psilocybin (.16 mg/kg) versus placebo on amygdala reactivity to negative stimuli in 25 healthy volunteers using blood oxygen level-dependent functional magnetic resonance imaging. Mood changes were assessed using the Positive and Negative Affect Schedule and the state portion of the State-Trait Anxiety Inventory. A double-blind, randomized, cross-over design was used with volunteers counterbalanced to receive psilocybin and placebo in two separate sessions at least 14 days apart.

Results
Amygdala reactivity to negative and neutral stimuli was lower after psilocybin administration than after placebo administration. The psilocybin-induced attenuation of right amygdala reactivity in response to negative stimuli was related to the psilocybin-induced increase in positive mood state.

Conclusions
These results demonstrate that acute treatment with psilocybin decreased amygdala reactivity during emotion processing and that this was associated with an increase of positive mood in healthy volunteers. These findings may be relevant to the normalization of amygdala hyperactivity and negative mood states in patients with major depression.

Kraehenmann, R., Preller, K. H., Scheidegger, M., Pokorny, T., Bosch, O. G., Seifritz, E., & Vollenwieder, F. X. (2014). Psilocybin-Induced Decrease in Amygdala Reactivity Correlates with Enhanced Positive Mood in Healthy Volunteers. Biological Psychiatry. http://dx.doi.org/10.1016/j.biopsych.2014.04.010
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A window into the intoxicated mind? Speech as an index of psychoactive drug effects.

April 3, 2014 / MDMA, Papers, Psychology, Publications / By / , , , , ,

Abstract

Abused drugs can profoundly alter mental states in ways that may motivate drug use. These effects are usually assessed with self-report, an approach that is vulnerable to biases. Analyzing speech during intoxication may present a more direct, objective measure, offering a unique ‘window’ into the mind. Here, we employed computational analyses of speech semantic and topological structure after ±3,4-methylenedioxymethamphetamine (MDMA; ‘ecstasy’) and methamphetamine in 13 ecstasy users. In 4 sessions, participants completed a 10-min speech task after MDMA (0.75 and 1.5 mg/kg), methamphetamine (20 mg), or placebo. Latent Semantic Analyses identified the semantic proximity between speech content and concepts relevant to drug effects. Graph-based analyses identified topological speech characteristics. Group-level drug effects on semantic distances and topology were assessed. Machine-learning analyses (with leave-one-out cross-validation) assessed whether speech characteristics could predict drug condition in the individual subject. Speech after MDMA (1.5 mg/kg) had greater semantic proximity than placebo to the concepts friend, support, intimacy, and rapport. Speech on MDMA (0.75 mg/kg) had greater proximity to empathy than placebo. Conversely, speech on methamphetamine was further from compassion than placebo. Classifiers discriminated between MDMA (1.5 mg/kg) and placebo with 88% accuracy, and MDMA (1.5 mg/kg) and methamphetamine with 84% accuracy. For the two MDMA doses, the classifier performed at chance. These data suggest that automated semantic speech analyses can capture subtle alterations in mental state, accurately discriminating between drugs. The findings also illustrate the potential for automated speech-based approaches to characterize clinically relevant alterations to mental state, including those occurring in psychiatric illness.

Bedi, G., Cecchi, G. A., Slezak, D. F., Carrillo, F., Sigman, M., & de Wit, H. (2014). A window into the intoxicated mind? speech as an index of psychoactive drug effects. Neuropsychopharmacology. https://dx.doi.org/10.1038/npp.2014.80

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Classical hallucinogens as antidepressants? A review of pharmacodynamics and putative clinical roles

March 17, 2014 / Anxiety Disorders / PTSD, Depressive Disorders, Mushrooms / Psilocybin, Neuroscience, Papers, Psychology, Publications / By / , , ,

Abstract

Hallucinogens have been part of spiritual practice for millennia, but controversy surrounding their mind-manifesting effects led to their proscription by the mid-20th century, largely without evidence of harm or toxicity and despite nascent data suggesting therapeutic utility in treating depressive illnesses. This review explores their pharmacodynamic actions and the current limited data on their clinic effectiveness. These drugs appear to exert their psychedelic effects through their agonist or partial agonist activity at the serotonergic 5-HT2A receptor, though they also have affinity for other metabotropic serotonin receptors. Hallucinogen binding affects a wide range of intracellular signalling pathways, the precise nature of which remains incompletely understood. They alter the serotonergic tone of brainstem raphe nuclei that project through the brain; they interact with receptors in the prefrontal cortex altering connectivity patterns and intracellular functioning; and they disrupt inhibitory control of sensory input via the thalamus to the cortex. The serotonergic system has long been implicated in anxiety and depressive disorders, and is a major target of most existing antidepressants. Classical hallucinogens alter the functioning of this system, but not in the same way current medications do: whilst there are identified receptors and neurotransmitter pathways through which hallucinogens could therein produce therapeutic effects, the neurobiology of this remains speculative at this time. There is currently an extremely limited but growing literature on hallucinogen safety and clinical application. The drugs appear well tolerated by healthy controls and clinical populations, and the rapid tolerance to repeated administration might reduce the possibility of dependency. Clinical trials reported over the past decade have generally shown positive therapeutic potential, but they are notably few in number. Legislative policy has had a freezing effect on evaluation of these compounds, a better understanding of which might improve our knowledge of the processes involved in consciousness, the neuropathology of depression, and potentially open up new pharmacological therapies.

Baumeister, D., Barnes, G., Giaroli, G., & Tracy, D. (2014). Classical hallucinogens as antidepressants? A review of pharmacodynamics and putative clinical roles. Therapeutic Advances in Psychopharmacology, 4(4), 156-159. http://dx.doi.org/10.1177/2045125314527985
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PTSD Symptom Reports of Patients Evaluated for the New Mexico Medical Cannabis Program

March 11, 2014 / Anxiety Disorders / PTSD, Papers, Psychology, Publications / By / , ,

Abstract

Background: New Mexico was the first state to list post-traumatic stress disorder (PTSD) as a condition for the use of medical cannabis. There are no published studies, other than case reports, of the effects of cannabis on PTSD symptoms. The purpose of the study was to report and statistically analyze psychometric data on PTSD symptoms collected during 80 psychiatric evaluations of patients applying to the New Mexico Medical Cannabis Program from 2009 to 2011. Methods: The Clinician Administered Posttraumatic Scale for DSM-IV (CAPS) was administered retrospectively and symptom scores were then collected and compared in a retrospective chart review of the first 80 patients evaluated. Results: Greater than 75% reduction in CAPS symptom scores were reported when patients were using cannabis compared to when they were not. Conclusions: Cannabis is associated with reductions in PTSD symptoms in some patients, and prospective, placebo-controlled study is needed to determine efficacy of cannabis and its constituents in treating PTSD.

Greer, G. R., Grob, C. S., & Halberstadt, A. L. (2014). PTSD Symptom Reports of Patients Evaluated for the New Mexico Medical Cannabis Program. Journal of Psychoactive Drugs, 46(1), 73–77. http://dx.doi.org/10.1080/02791072.2013.873843
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Therapeutic Effects of Ritual Ayahuasca Use in the Treatment of Substance Dependence—Qualitative Results

March 11, 2014 / Ayahuasca, Biology & Ethnobotany, Neuroscience, Papers, Psychology, Publications, Substance Use Disorder / By / ,

Abstract

This qualitative empirical study explores the ritual use of ayahuasca in the treatment of addictions. Ayahuasca is an Amazonian psychedelic plant compound created from an admixture of the vine Banisteriopsis caapi and the bush Psychotria viridis. The study included interviews with 13 therapists who apply ayahuasca professionally in the treatment of addictions (four indigenous healers and nine Western mental health professionals with university degrees), two expert researchers, and 14 individuals who had undergone ayahuasca-assisted therapy for addictions in diverse contexts in South America. The study provides empirically based hypotheses on therapeutic mechanisms of ayahuasca in substance dependence treatment. Findings indicate that ayahuasca can serve as a valuable therapeutic tool that, in carefully structured settings, can catalyze neurobiological and psychological processes that support recovery from substance dependencies and the prevention of relapse. Treatment outcomes, however, can be influenced by a number of variables that are explained in this study. In addition, issues related to ritual transfer and strategies for minimizing undesired side-effects are discussed.

Loizaga-Velder, A., & Verres, R. (2014). Therapeutic Effects of Ritual Ayahuasca Use in the Treatment of Substance Dependence—Qualitative Results. Journal of Psychoactive Drugs, 46(1), 63–72. http://dx.doi.org/10.1080/02791072.2013.873157
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Why Psychiatry Needs Psychedelics and Psychedelics Need Psychiatry

March 11, 2014 / Anxiety Disorders / PTSD, Depressive Disorders, LSD, MDMA, Mushrooms / Psilocybin, Papers, Psychology, Publications, Substance Use Disorder / By /

Abstract

Without researching psychedelic drugs for medical therapy, psychiatry is turning its back on a group of compounds that could have great potential. Without the validation of the medical profession, the psychedelic drugs, and those who take them off-license, remain archaic sentiments of the past, with the users maligned as recreational drug abusers and subject to continued negative opinion. These two disparate groups—psychiatrists and recreational psychedelic drug users—are united by their shared recognition of the healing potential of these compounds. A resolution of this conflict is essential for the future of psychiatric medicine and psychedelic culture alike. Progression will come from professionals working in the field adapting to fit a conservative paradigm. In this way, they can provide the public with important treatments and also raise the profile of expanded consciousness in mainstream society.

Sessa, B. (2014). Why Psychiatry Needs Psychedelics and Psychedelics Need Psychiatry. Journal of Psychoactive Drugs, 46(1), 57–62. http://dx.doi.org/10.1080/02791072.2014.877322
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MDMA and the “Ecstasy Paradigm”

March 11, 2014 / MDMA, Neuroscience, Papers, Psychology, Publications / By /

Abstract

For nearly 30 years, there has been a steady flow of research papers highlighting the dangers of MDMA and the implications for ecstasy users. After such a long time, it would be reasonable to expect that these dangers would be obvious due to the large number of ecstasy users. The available evidence does not indicate that there are millions of ecstasy users experiencing any problems linked to their ecstasy use. The “precautionary principle” suggests that, in the absence of knowing for certain, “experts” should argue that MDMA be avoided. However, this may have been taken too far, as the dire warnings do not seem to be reducing with the lack of epidemiological evidence of clinically relevant problems. The “ecstasy paradigm” is one way of articulating this situation, in that the needs of research funders and publication bias lead to a specific set of subcultural norms around what information is acceptable in the public domain. By digging a little deeper, it is easy to find problems with the evidence base that informs the public debate around MDMA. The key question is whether it is acceptable to maintain this status quo given the therapeutic potential of MDMA.

Cole, J. C. (2014). MDMA and the “Ecstasy Paradigm”. Journal of Psychoactive Drugs, 46(1), 44–56. http://dx.doi.org/10.1080/02791072.2014.878148
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The Potential Dangers of Using MDMA for Psychotherapy

March 11, 2014 / Anxiety Disorders / PTSD, MDMA, Neuroscience, Papers, Psychology, Publications / By /

Abstract

MDMA has properties that may make it attractive for psychotherapy, although many of its effects are potentially problematic. These contrasting effects will be critically reviewed in order to assess whether MDMA could be safe for clinical usage. Early studies from the 1980s noted that MDMA was an entactogen, engendering feelings of love and warmth. However, negative experiences can also occur with MDMA since it is not selective in the thoughts or emotions it releases. This unpredictability in the psychological material released is similar to another serotonergic drug, LSD. Acute MDMA has powerful neurohormonal effects, increasing cortisol, oxytocin, testosterone, and other hormone levels. The release of oxytocin may facilitate psychotherapy, whereas cortisol may increase stress and be counterproductive. MDMA administration is followed by a period of neurochemical recovery, when low serotonin levels are often accompanied by lethargy and depression. Regular usage can also lead to serotonergic neurotoxicity, memory problems, and other psychobiological problems. Proponents of MDMA-assisted therapy state that it should only be used for reactive disorders (such as PTSD) since it can exacerbate distress in those with a prior psychiatric history. Overall, many issues need to be considered when debating the relative benefits and dangers of using MDMA for psychotherapy.

Parrott, A. C. (2014). The Potential Dangers of Using MDMA for Psychotherapy. Journal of Psychoactive Drugs, 46(1) , 37–43. http://dx.doi.org/10.1080/02791072.2014.873690
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