Therapeutic Applications of Classic Hallucinogens
Abstract
Bogenschutz, M. P., & Ross, S. (2016). Therapeutic applications of classic hallucinogens. 10.1007/7854_2016_464
Link to full text
Despite several studies suggesting the therapeutic use of 5-hydroxytryptamine receptors type 2A (5-HT2A) agonists in the treatment of substance use disorders, the neurobiological basis accounting for such effects are still unknown. It has been observed that chronic exposure to drugs of abuse produces molecular and cellular adaptations in ventral tegmental area (VTA) neurons, mediated by brain-derived neurotrophic factor (BDNF). These BDNF-induced adaptations in the VTA are associated with the establishment of aversive withdrawal motivation that leads to a drug-dependent state. Growing evidence suggests that 5-HT2A receptor signaling can regulate the expression of BDNF in the brain. In this study, we observed that a single systemic or intra-VTA administration of a 5-HT2A agonist in rats and mice blocks both the aversive conditioned response to drug withdrawal and the mechanism responsible for switching from a drug-naive to a drug-dependent motivational system. Our results suggest that 5-HT2A agonists could be used as therapeutic agents to reverse a drug dependent state, as well as inhibiting the aversive effects produced by drug withdrawal.
Vargas‐Perez, H., Grieder, T. E., Ting‐A‐Kee, R., Maal‐Bared, G., Chwalek, M., & van der Kooy, D. (2017). A single administration of the hallucinogen, 4‐acetoxy‐dimethyltryptamine, prevents the shift to a drug‐dependent state and the expression of withdrawal aversions in rodents. European Journal of Neuroscience. 10.1111/ejn.13572
Link to full text
The psychological mechanisms of action involved in psilocybin-assisted psychotherapy are not yet well understood. Despite a resurgence of quantitative research regarding psilocybin, the current study is the first qualitative study of participant experiences in psilocybin-assisted psychotherapy. Semistructured interviews were carried out with 13 adult participants aged 22 to 69 years (M = 50 years) with clinically elevated anxiety associated with a cancer diagnosis. Participants received a moderate dose of psilocybin and adjunctive psychotherapy with an emphasis on the process of meaning-making. Verbatim transcribed interviews were analyzed by a five-member research team using interpretative phenomenological analysis. General themes found in all or nearly all transcripts included relational embeddedness, emotional range, the role of music as conveyor of experience, meaningful visual phenomena, wisdom lessons, revised life priorities, and a desire to repeat the psilocybin experience. Typical themes found in the majority of transcripts included the following: exalted feelings of joy, bliss, and love; embodiment; ineffability; alterations to identity; a movement from feelings of separateness to interconnectedness; experiences of transient psychological distress; the appearance of loved ones as guiding spirits; and sharing the experience with loved ones posttreatment. Variant themes found in a minority of participant transcripts include lasting changes to sense of identity, synesthesia experiences, catharsis of powerful emotion, improved relationships after treatment, surrender or “letting go,” forgiveness, and a continued struggle to integrate experience. The findings support the conclusion that psilocybin-assisted psychotherapy may provide an effective treatment for psychological distress in cancer patients. Implications for theory and treatment are discussed.
Belser, A. B., Agin-Liebes, G., Swift, T. C., Terrana, S., Devenot, N., Friedman, H. L., … & Ross, S. (2017). Patient experiences of psilocybin-assisted psychotherapy: An interpretative phenomenological analysis. Journal of Humanistic Psychology, 0022167817706884.
Link to full text
Plant-based psychedelics, such as psilocybin, have an ancient history of medicinal use. After the first English language report on LSD in 1950, psychedelics enjoyed a short-lived relationship with psychology and psychiatry. Used most notably as aids to psychotherapy for the treatment of mood disorders and alcohol dependence, drugs such as LSD showed initial therapeutic promise before prohibitive legislature in the mid-1960s effectively ended all major psychedelic research programs. Since the early 1990s, there has been a steady revival of human psychedelic research: last year saw reports on the first modern brain imaging study with LSD and three separate clinical trials of psilocybin for depressive symptoms. In this circumspective piece, RLC-H and GMG share their opinions on the promises and pitfalls of renewed psychedelic research, with a focus on the development of psilocybin as a treatment for depression.
Carhart-Harris, R. L., & Goodwin, G. M. (2017). The Therapeutic Potential of Psychedelic Drugs: Past, Present, and Future. Neuropsychopharmacology. 10.1038/npp.2017.84
Link to full text
INTRODUCTION: Psilocybin is a psychedelic tryptamine that has shown promise in recent clinical trials for the treatment of depression and substance use disorders. This open-label study of the pharmacokinetics of psilocybin was performed to describe the pharmacokinetics and safety profile of psilocybin in sequential, escalating oral doses of 0.3, 0.45, and 0.6 mg/kg in 12 healthy adults.
METHODS: Eligible healthy adults received 6-8 h of preparatory counseling in anticipation of the first dose of psilocybin. The escalating oral psilocybin doses were administered at approximately monthly intervals in a controlled setting and subjects were monitored for 24 h. Blood and urine samples were collected over 24 h and assayed by a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for psilocybin and psilocin, the active metabolite. The pharmacokinetics of psilocin were determined using both compartmental (NONMEM) and noncompartmental (WinNonlin) methods.
RESULTS: No psilocybin was found in plasma or urine, and renal clearance of intact psilocin accounted for less than 2% of the total clearance. The pharmacokinetics of psilocin were linear within the twofold range of doses, and the elimination half-life of psilocin was 3 h (standard deviation 1.1). An extended elimination phase in some subjects suggests hydrolysis of the psilocin glucuronide metabolite. Variation in psilocin clearance was not predicted by body weight, and no serious adverse events occurred in the subjects studied.
CONCLUSIONS: The small amount of psilocin renally excreted suggests that no dose reduction is needed for subjects with mild-moderate renal impairment. Simulation of fixed doses using the pharmacokinetic parameters suggest that an oral dose of 25 mg should approximate the drug exposure of a 0.3 mg/kg oral dose of psilocybin. Although doses of 0.6 mg/kg are in excess of likely therapeutic doses, no serious physical or psychological events occurred during or within 30 days of any dose.
Brown, R. T., Nicholas, C. R., Cozzi, N. V., Gassman, M. C., Cooper, K. M., Muller, D., … & Hutson, P. R. (2017). Pharmacokinetics of Escalating Doses of Oral Psilocybin in Healthy Adults. Clinical Pharmacokinetics, 1-12. 10.1007/s40262-017-0540-6
Link to full text
Data suggest psychedelics such as psilocybin and lysergic acid diethylamide (LSD) may hold therapeutic potential in the treatment of addictions, including tobacco dependence. This retrospective cross-sectional anonymous online survey characterized 358 individuals (52 females) who reported having quit or reduced smoking after ingesting a psychedelic in a non-laboratory setting ⩾1 year ago. On average, participants smoked 14 cigarettes/day for 8 years, and had five previous quit attempts before their psychedelic experience. Of the 358 participants, 38% reported continuous smoking cessation after psychedelic use (quitters). Among quitters, 74% reported >2 years’ abstinence. Of the 358 participants, 28% reported a persisting reduction in smoking (reducers), from a mode of 300 cigarettes/month before, to a mode of 1 cigarette/month after the experience. Among reducers, 62% reported >2 years of reduced smoking. Finally, 34% of the 358 participants (relapsers) reported a temporary smoking reduction before returning to baseline smoking levels, with a mode time range to relapse of 3–6 months. Relapsers rated their psychedelic experience significantly lower in personal meaning and spiritual significance than both other groups. Participants across all groups reported less severe affective withdrawal symptoms (e.g. depression, craving) after psychedelic use compared with previous quit attempts, suggesting a potential mechanism of action for psychedelic-associated smoking cessation/reduction. Changes in life priorities/values were endorsed as the most important psychological factor associated with smoking cessation/reduction. Results suggest psychedelics may hold promise in treating tobacco addiction as potentially mediated by spiritual experience, changed priorities/values, and improved emotional regulation.
Johnson, M. W., Garcia-Romeu, A., Johnson, P. S., & Griffiths, R. R. (2017). An online survey of tobacco smoking cessation associated with naturalistic psychedelic use. Journal of Psychopharmacology, 0269881116684335. 10.1177/0269881116684335
Link to full text