OPEN Foundation

Neuroscience

The persistence of the subjective in neuropsychopharmacology: observations of contemporary hallucinogen research

February 26, 2010 / Ayahuasca, Cacti / Mescaline, DMT, Iboga / Ibogaine, Ketamine, LSD, MDMA, Mushrooms / Psilocybin, Neuroscience, Other disciplines, Other subjects, Other substances, Papers, Psychology, Psychopharmacology, Publications, Salvia / Salvinorin A / By /

Abstract

The elimination of subjectivity through brain research and the replacement of so-called ‘folk psychology’ by a neuroscientifically enlightened worldview and self-conception has been both hoped for and feared. But this cultural revolution is still pending. Based on nine months of fieldwork on the revival of hallucinogen research since the ‘Decade of the Brain,’ this paper examines how subjective experience appears as epistemic object and practical problem in a psychopharmacological laboratory. In the quest for neural correlates of (drug-induced altered states of) consciousness, introspective accounts of test subjects play a crucial role in neuroimaging studies. Firsthand knowledge of the drugs’ flamboyant effects provides researchers with a personal knowledge not communicated in scientific publications, but key to the conduct of their experiments. In many cases, the ‘psychedelic experience’ draws scientists into the field and continues to inspire their self-image and way of life. By exploring these domains the paper points to a persistence of the subjective in contemporary neuropsychopharmacology.

Langlitz, N. (2010). The persistence of the subjective in neuropsychopharmacology: observations of contemporary hallucinogen research. History of Human Sciences, 23(1), 37-57. http://dx.doi.org/10.1177/0952695109352413
Link to full text

How could MDMA (ecstasy) help anxiety disorders? A neurobiological rationale

March 9, 2009 / Anxiety disorders / PTSD, MDMA, Neuroscience, Papers, Psychiatry, Psychology, Psychopharmacology, Psychotherapy, Publications / By / ,

Abstract

Exposure therapy is known to be an effective treatment for anxiety disorders. Nevertheless, exposure is not used as much as it should be, and instead patients are often given supportive medications such as serotonin reuptake inhibitors (SSRIs) and benzodiazepines, which may even interfere with the extinction learning that is the aim of treatment. Given that randomized controlled trials are now investigating a few doses of ±3,4-methylenedioxymethamphetamine (MDMA, ‘ecstasy’) in combination with psychotherapy for treatment-resistant anxiety disorders, we would like to suggest the following three mechanisms for this potentially important new approach: 1) MDMA increases oxytocin levels, which may strengthen the therapeutic alliance; 2) MDMA increases ventromedial prefrontal activity and decreases amygdala activity, which may improve emotional regulation and decrease avoidance and 3) MDMA increases norepinephrine release and circulating cortisol levels, which may facilitate emotional engagement and enhance extinction of learned fear associations. Thus, MDMA has a combination of pharmacological effects that, in a therapeutic setting, could provide a balance of activating emotions while feeling safe and in control, as described in case reports of MDMA-augmented psychotherapy. Further clinical and preclinical studies of the therapeutic value of MDMA are indicated.

Johansen, P. Ø., & Krebs, T. S. (2009). How could MDMA (ecstasy) help anxiety disorders? A neurobiological rationale. Journal of Psychopharmacology, 23(4), 389-391. http://dx.doi.org/10.1177/0269881109102787
Link to full text

Gaddum and LSD: the birth and growth of experimental and clinical neuropharmacology research on 5-HT in the UK

January 29, 2009 / Depression, LSD, Medicine, Neuroscience, Other subjects, Other substances, Papers, Psychopharmacology, Psychotherapy, Publications / By /

Abstract

The vasoconstrictor substance named serotonin was identified as 5-hydroxytryptamine (5-HT) by Maurice Rapport in 1949. In 1951, Rapport gave Gaddum samples of 5-HT substance allowing him to develop a bioassay to both detect and measure the amine. Gaddum and colleagues rapidly identified 5-HT in brain and showed that lysergic acid diethylamide (LSD) antagonized its action in peripheral tissues. Gaddum accordingly postulated that 5-HT might have a role in mood regulation. This review examines the role of UK scientists in the first 20 years following these major discoveries, discussing their role in developing assays for 5-HT in the CNS, identifying the enzymes involved in the synthesis and metabolism of 5-HT and investigating the effect of drugs on brain 5-HT. It reviews studies on the effects of LSD in humans, including Gaddum’s self-administration experiments. It outlines investigations on the role of 5-HT in psychiatric disorders, including studies on the effect of antidepressant drugs on the 5-HT concentration in rodent and human brain, and the attempts to examine 5-HT biochemistry in the brains of patients with depressive illness. It is clear that a rather small group of both preclinical scientists and psychiatrists in the UK made major advances in our understanding of the role of 5-HT in the brain, paving the way for much of the knowledge now taken for granted when discussing ways that 5-HT might be involved in the control of mood and the idea that therapeutic drugs used to alleviate psychiatric illness might alter the function of cerebral 5-HT.

Green, A. R. (2008). Gaddum and LSD: the birth and growth of experimental and clinical neuropharmacology research on 5‐HT in the UK. British journal of pharmacology, 154(8), 1583-1599., 10.1038/bjp.2008.207
Link to full text

Serotonin-Related Psychedelic Drugs

November 5, 2008 / Cacti / Mescaline, LSD, Mushrooms / Psilocybin, Neuroscience, Papers, Psychiatry, Psychology, Psychopharmacology, Psychotherapy, Publications / By / , ,

Abstract

Serotonergic hallucinogens include the prototypical compounds such as mescaline, psilocybin, and LSD, representing the chemical classes of phenethylamines, tryptamines, and ergolines. Known as psychedelics, these compounds induce dramatic alterations of perception, affect, consciousness, and the experience of self. As first discovered in animal studies and recently confirmed in humans, the psychological effects of psychedelics are primarily attributable to the activation of the 5-HT2A subtype of serotonin receptors in brain. Research on psychedelic compounds has provided important insights into the neurobiology of consciousness and naturally occurring psychotic states and may lead to further advances in the development of psychiatric pharmacotherapeutics.

Geyer, M. A., Nichols, D. E., & Vollenweider, F. X. (2009). Serotonin-related psychedelic drugs. 10.1016/B978-008045046-9.01160-8
Link to full text

The Phenomenology and Potential Religious Import of States of Consciousness Facilitated by Psilocybin

October 30, 2008 / Mushrooms / Psilocybin, Mystical experiences, Neuroscience, Papers, Personal development, Phenomenology, Psychiatry, Psychology, Psychopharmacology, Psychotherapy, Publications, Religious studies, Spirituality / By /

Abstract

Accompanying the resumption of human research with the entheogen (psychedelic drug), psilocybin, the range of states of consciousness reported during its action, including both nonmystical and mystical forms of experience, is surveyed and defined. The science and art of facilitating mystical experiences is discussed on the basis of research experience. The potential religious import of these states of consciousness is noted in terms of recognizing the reality of the spiritual, in better understanding the biochemistry of revelation, and in exploring the potentially positive contributions that mystical consciousness may effect in psychological treatment.

Richards, W. A. (2008). The Phenomenology and Potential Religious Import of States of Consciousness Facilitated by Psilocybin. Archive for the Psychology of Religion, 30, 189-199. http://dx.doi.org/10.1163/157361208X317196
Link to full text

Human hallucinogen research: guidelines for safety

July 1, 2008 / Ayahuasca, Cacti / Mescaline, DMT, Iboga / Ibogaine, Ketamine, LSD, MDMA, Medicine, Mushrooms / Psilocybin, Neuroscience, Other substances, Papers, Psychiatry, Psychology, Psychopharmacology, Publications, Safety, Salvia / Salvinorin A / By / , ,

Abstract

There has recently been a renewal of human research with classical hallucinogens (psychedelics). This paper first briefly discusses the unique history of human hallucinogen research, and then reviews the risks of hallucinogen administration and safeguards for minimizing these risks. Although hallucinogens are relatively safe physiologically and are not considered drugs of dependence, their administration involves unique psychological risks. The most likely risk is overwhelming distress during drug action (‘bad trip’), which could lead to potentially dangerous behaviour such as leaving the study site. Less common are prolonged psychoses triggered by hallucinogens. Safeguards against these risks include the exclusion of volunteers with personal or family history of psychotic disorders or other severe psychiatric disorders, establishing trust and rapport between session monitors and volunteer before the session, careful volunteer preparation, a safe physical session environment and interpersonal support from at least two study monitors during the session. Investigators should probe for the relatively rare hallucinogen persisting perception disorder in follow-up contact. Persisting adverse reactions are rare when research is conducted along these guidelines. Incautious research may jeopardize participant safety and future research. However, carefully conducted research may inform the treatment of psychiatric disorders, and may lead to advances in basic science.

Johnson, M. W., Richards, W. A., & Griffiths, R. R. (2008). Human hallucinogen research: guidelines for safety.  Journal of Psychopharmacology, 22(6), 603–620. http://dx.doi.org/10.1177/0269881108093587
Link to full text

[Hallucinogen-induced psychological disorders]

June 1, 2008 / HPPD, LSD, Mushrooms / Psilocybin, Neuroscience, Papers, Psychiatry, Psychology, Psychopharmacology, Psychosis, Publications / By / , , ,

Abstract

OBJECTIVE:

The purpose of this article is to provide an overview of the current research on hallucinogen induced psychiatric disorders. In addition to LSD and psilocybin hallucinogens of biologic origin are increasingly used by adolescents and young adults.

METHODS:

Relevant literature and related articles were identified by means of a computerized MEDLINE search including the years 1997 – 2007. As keywords “hallucinogen induced psychosis”, “hallucinogen induced flashback”, “hallucinogen persisting perception disorder (HPPD)” were used. Finally, 64 journal articles and books out of 103 were included in the review.

RESULTS:

Acute psychotic syndromes in adolescents are rarely due to intoxications with hallucinogenic drugs. However, clinical relevance of flashback phenomena as post-hallucinogenic psychiatric disorder has to be disputed. Because of the high popularity of biogenic hallucinogens and LSD knowledge of intoxications and resulting psychiatric disorders as well as medical complications and therapeutical approaches are clinically important. Especially intoxications with drugs of herbal origin like tropanalcaloids play an important role in emergency situations.

Hermle, L., Kovar, K. A., Hewer, W., & Ruchsow, M. (2008). [Hallucinogen-induced psychological disorders]. Fortschritte der Neurologie-Psychiatrie, 76(6), 334-342. http://dx.doi.org/10.1055/s-2008-1038191
Link to full text [Article in German]

Selective 5-HT2A agonist hallucinogens: A review of pharmacological interaction and corollary perceptual effects

May 23, 2008 / DMT, LSD, Mushrooms / Psilocybin, Neuroscience, Other subjects, Papers, Psychology, Psychopharmacology, Publications / By /

Abstract

The most potent tryptamine hallucinogens – such as DMT, psilocybin, and LSD – are all active at the 5-HT2A receptor subtype and all produce similar visual perceptual results that are immediately recognizable as uniquely psychedelic. Although it is widely accepted that selective serotonin receptor subtype 2A agonism is directly responsible for producing the distinct hallucinations seen on a psychedelic trip, no single theory has yet explained why this is so. Utilizing what we know about psychedelic tryptamine receptor interaction, sensory processing circuits in the neocortex, and EEG scans of psychedelics in action, this review will propose a novel multi-state theory of psychedelic action which invokes a variety of neural processing mechanisms, including phase-coupled neural oscillators; network excitation, disinhibition, and destabilization; recurrent feedback excitation; and neural circuit spike synchrony and brainwave cohesion to close the knowledge gap between the pharmaceutical interactions of selective 5-HT2A hallucinogens, their direct effects on perception and consciousness at varying dose ranges, and their potential long-term adverse effects.

Kent, J. (2008). Selective 5-HT2A agonist hallucinogens: A review of pharmacological interaction and corollary perceptual effects. Beta Review.

Link to full text

Psilocybin links binocular rivalry switch rate to attention and subjective arousal levels in humans

September 14, 2007 / Mushrooms / Psilocybin, Neuroscience, Other subjects, Papers, Psychiatry, Psychopharmacology, Publications / By / , , , , ,

Abstract

Rationale: Binocular rivalry occurs when different images are simultaneously presented to each eye. During continual viewing of this stimulus, the observer will experience repeated switches between visual awareness of the two images. Previous studies have suggested that a slow rate of perceptual switching may be associated with clinical and drug-induced psychosis.

Objectives: The objective of the study was to explore the proposed relationship between binocular rivalry switch rate and subjective changes in psychological state associated with 5-HT2A receptor activation.

Materials and methods: This study used psilocybin, the hallucinogen found naturally in Psilocybe mushrooms that had previously been found to induce psychosis-like symptoms via the 5-HT2A receptor. The effects of psilocybin (215 μg/kg) were considered alone and after pretreatment with the selective 5-HT2A antagonist ketanserin (50 mg) in ten healthy human subjects.

Results: Psilocybin significantly reduced the rate of binocular rivalry switching and increased the proportion of transitional/mixed percept experience. Pretreatment with ketanserin blocked the majority of psilocybin’s “positive” psychosis-like hallucinogenic symptoms. However, ketanserin had no influence on either the psilocybin-induced slowing of binocular rivalry or the drug’s “negative-type symptoms” associated with reduced arousal and vigilance.

Conclusions: Together, these findings link changes in binocular rivalry switching rate to subjective levels of arousal and attention. In addition, it suggests that psilocybin’s effect on binocular rivalry is unlikely to be mediated by the 5-HT2A receptor.

Carter, O. L., Hasler, F., Pettigrew, J. D., Wallis, G. M., Liu, G. B., & Vollenweider, F. X. (2007). Psilocybin links binocular rivalry switch rate to attention and subjective arousal levels in humans. Psychopharmacology, 195(3), 415-424. 10.1007/s00213-007-0930-9

Link to full text

Psilocybin-induced stimulus control in the rat

June 22, 2007 / Mushrooms / Psilocybin, Neuroscience, Other subjects, Papers, Psychopharmacology, Publications / By / , , ,

Abstract

Although psilocybin has been trained in the rat as a discriminative stimulus, little is known of the pharmacological receptors essential for stimulus control. In the present investigation rats were trained with psilocybin and tests were then conducted employing a series of other hallucinogens and presumed antagonists. An intermediate degree of antagonism of psilocybin was observed following treatment with the 5-HT2A receptor antagonist, M100907. In contrast, no significant antagonism was observed following treatment with the 5-HT1A/7 receptor antagonist, WAY-100635, or the DA D2 antagonist, remoxipride. Psilocybin generalized fully to DOM, LSD, psilocin, and, in the presence of WAY-100635, DMT while partial generalization was seen to 2C-T-7 and mescaline. LSD and MDMA partially generalized to psilocybin and these effects were completely blocked by M-100907; no generalization of PCP to psilocybin was seen. The present data suggest that psilocybin induces a compound stimulus in which activity at the 5-HT2A receptor plays a prominent but incomplete role. In addition, psilocybin differs from closely related hallucinogens such as 5-MeO-DMT in that agonism at 5-HT1A receptors appears to play no role in psilocybin-induced stimulus control.

Winter, J. C., Rice, K. C., Amorosi, D. J., & Rabin, R. A. (2007). Psilocybin-induced stimulus control in the rat. Pharmacology Biochemistry and Behavior, 87(4), 472-480. http://dx.doi.org/10.1016/j.pbb.2007.06.003
Link to full text

22 May - Delivering Effective Psychedelic Clinical Trials

REGISTER NOW!
X