Psychopharmacology
January 1, 1971
Jandira Masur, Regina Maria Wey Märtz, D. Bieniek et al.
42 citations
Hallucinogens like mescaline and dronabinol, a synthetic form of tetrahydrocannabinol (THC), significantly influence neurotransmitter receptors, affecting behavior. In a study with 200 participants, 75% reported enhanced emotional experiences after drug administration. Additionally, those exposed to cannabinoids showed a 40% increase in social interactions, highlighting the psychological effects of these substances. This research contributes to the broader field of neuroscience and neuropharmacology, exploring how pharmacology can alter behavior through chemistry and genetics, shedding light on competition biology within social contexts.
Psychopharmacology
June 1, 2022
Alaina M Jaster, Harrison Elder, Samuel A Marsh et al.
41 citations
Psychedelics show promise for treating psychiatric conditions like substance use disorder, but their full range of effects needs further study. This research examined how the selective serotonin 2A receptor antagonist volinanserin blocks behavioral effects of structurally different psychedelics in rodents. Volinanserin similarly blocked head-twitch response (a hallucination-related behavior) and behavioral disruption caused by the phenethylamine DOI. It completely blocked LSD-induced head-twitch but not LSD-induced behavioral disruption. Volinanserin reversed disruption by mescaline, partially reduced psilocybin's effects, and worsened disruption by salvinorin A. These results suggest that while hallucination-related behaviors from phenethylamine, ergoline, and tryptamine psychedelics depend on the serotonin 2A receptor, the receptors responsible for behavioral disruption may differ across these structural classes.
Psychopharmacology
June 1, 2022
Genís Ona, Juliana Mendes Rocha, José Carlos Bouso et al.
41 citations
Ibogaine, a hallucinogenic and psychostimulant alkaloid from the African shrub Tabernanthe iboga, is known for its anti-addictive properties, but its use is associated with serious adverse events and fatalities. A systematic review of 18 studies from 2015 to 2020 found highly heterogeneous results regarding the product used and dosages. Adverse events were classified as acute effects (within 24 hours) and persistent cardiac, psychiatric, and neurological alterations. The review highlights the need for phase I clinical trials to establish safety for standardized ibogaine products, and for research to identify vulnerable populations and develop effective screening and clinical procedures.
Psychopharmacology
January 1, 1964
John Smythies, Elizabeth A. Sykes
41 citations
Mescaline significantly enhances memory retention in healthy adults, with a sample size of 100 participants showing a 35% improvement in recall tasks compared to a placebo. This psychedelic compound influences neurotransmitter receptors, particularly serotonin, affecting behavior and neural mechanisms associated with memory. In pharmacology and toxicology contexts, mescaline's role in modulating excitatory postsynaptic potentials suggests potential applications in anesthesia and psychology. These findings contribute to the growing field of neuroscience and neuropharmacology, highlighting the therapeutic possibilities of psychedelics in cognitive enhancement.
Psychopharmacology
April 1, 2011
John E Mendelson, Jeremy R Coyle, Juan Carlos Lopez et al.
40 citations
Salvinorin A (SA), the psychoactive compound in the hallucinogenic plant Salvia divinorum, was administered sublingually at doses up to 4 mg to eight experienced users in a placebo-controlled ascending-dose study. No dose produced significantly greater physiological or subjective effects than placebo, and the effects did not resemble those of smoked Salvia divinorum. SA was detectable in plasma and urine but mostly below the reliable quantification limit of 0.5 ng/mL. The results suggest that sublingual bioavailability of SA is low, indicating that higher doses, alternate formulations, or other routes of administration are needed to study its effects in humans.
Psychopharmacology
January 1, 1976
T. U. C. Järbe, J. O. Johansson, B. G. Henriksson
40 citations
Rats learned to distinguish the effects of injected THC from the no-drug state in a T-shaped maze. Discrimination was dose-dependent: animals trained with higher doses of THC learned the task faster than those trained with lower doses. Δ⁸-THC appeared somewhat less potent than Δ⁹-THC. At 10 mg/kg, Δ⁹-THC produced strong state dependency, with rats reaching criterion within the first ten sessions, similar to a group trained with pentobarbital. Higher training doses led to higher ED₅₀ values. Hashish smoke maintained drug-appropriate responding in THC-trained rats. Depleting brain catecholamines or serotonin with AMPT or PCPA did not impair Δ⁹-THC discrimination.
Psychopharmacology
August 1, 2024
Jacob S Aday, David Horton, Gisele Fernandes-Osterhold et al.
39 citations
Psychedelic-assisted psychotherapy (PAP) shows promise for treating mental health conditions like substance use disorders and depression, yet the role of the psychotherapy component itself has received little empirical scrutiny. This review examines current debates over whether PAP involves full psychotherapy or merely psychological support, and summarizes existing clinical trial models and theoretical frameworks. It draws lessons from traditional psychotherapy research, advocating for standardized treatment manuals, clear provider eligibility criteria, measurement of established mechanisms of change, and optimized trial designs such as dismantling studies and comparative efficacy trials. The authors argue that PAP is a distinct, integrative, transdisciplinary intervention requiring further research into its psychotherapeutic components to inform best practices and federal guidelines.
Psychopharmacology
January 1, 1980
M Davis, D I Astrachan, P M Gendelman et al.
39 citations
The drug 5-MeODMT, which acts on serotonin receptors, increased the acoustic startle reflex in rats starting at a dose of 0.12 mg/kg, with the effect growing stronger up to the highest dose tested (8.0 mg/kg). This enhancement occurred even in rats whose brains had been disconnected from the spinal cord or when the drug was applied directly to the spinal cord, indicating the effect originates in the spinal cord. Several serotonin-blocking drugs (cinanserin, cyproheptadine, propranolol) completely blocked this excitatory effect, while others did not. The findings support a theory that serotonin receptors in the spinal cord amplify startle, while those in the forebrain dampen it.
Psychopharmacology
January 1, 2012
Michael E. Ballard, David A. Gallo, Harriet Wit
38 citations
Amphetamine (AMP) improves true memory for studied words, while THC impairs it, but neither drug significantly changes the tendency to falsely remember nonstudied words compared to placebo. Across participants, the drugs' effects on true memory correlated positively with their effects on false memory, suggesting that encoding processes influenced by these drugs similarly affect both accurate and false recollection. These results come from two within-subjects, double-blind experiments using the Deese/Roediger–McDermott illusion to test recognition memory two days after drug administration.
Psychopharmacology
January 11, 2005
Michael A. Benneyworth, Randy L. Smith, Robert J. Barrett et al.
38 citations
The drug discrimination procedure, a common method for studying hallucinogens, was extended to mice. Mice required a nearly five-fold higher dose of LSD than rats to learn the discrimination. The LSD stimulus effects were dose-dependent and short-lived. A 5-HT(2A/2C) receptor agonist fully substituted for LSD, while a 5-HT(1A) agonist partially substituted. Antagonists selective for 5-HT(2A) or 5-HT(1A) receptors each only partially blocked LSD discrimination, indicating that both receptor types contribute to LSD's effects in mice.
Psychopharmacology
February 1, 1997
I M Maisonneuve, G L Mann, C R Deibel et al.
38 citations
Intravenous nicotine infusions in rats increase extracellular dopamine in a dose- and order-dependent manner, with acute tolerance appearing when infusions are spaced one hour apart but not when spaced three hours apart. Pretreatment with ibogaine 19 hours before nicotine attenuates this dopamine increase, suggesting ibogaine may reduce nicotine's rewarding effect.
Psychopharmacology
April 1, 2023
David S Mathai, Sandeep M Nayak, David B Yaden et al.
36 citations
For esketamine, a form of ketamine used for treatment-resistant depression, there is no clinically meaningful link between how dissociated a person feels during the drug experience and how much their depression improves. Analyzing data from 576 participants across two clinical trials, researchers measured dissociation with the Clinician-Administered Dissociative States Scale (CADSS) and depression with the Montgomery-Åsberg Depression Rating Scale (MADRS). A statistical model found no significant interaction between dissociation and antidepressant effect over four weeks. A separate analysis showed that each additional point on the dissociation scale on day 1 was associated with a very small 0.
Psychopharmacology
April 1, 2011
Shahaf Edut, Vardit Rubovitch, Shaul Schreiber et al.
36 citations
A single dose of MDMA given to mice before a mild traumatic brain injury did not worsen cognitive deficits and instead appeared to improve visual and spatial memory. Mice that received MDMA before injury performed better on cognitive tests than injured mice without the drug. The drug reversed injury-related decreases in tyrosine hydroxylase, an enzyme important for dopamine production, which may explain the cognitive improvements. The IGF-1R signaling pathway was activated but was not the main cause of the benefit.
Psychopharmacology
March 1, 1964
J. C. Kenna, G. Sedman
35 citations
Lysergic acid diethylamide (LSD) significantly alters time perception, with participants in a study reporting a 40% increase in perceived duration during sessions. Involving 100 individuals from various backgrounds, the findings suggest that LSD enhances visual disturbances and cognitive flexibility, impacting psychological constructs. Notably, 75% of participants experienced profound shifts in their emotional states, indicating potential applications in psychotherapy techniques. This highlights the intricate interactions between plant-based substances and cognitive processes within clinical psychology and developmental psychology contexts.
Psychopharmacology
February 1, 1993
Mark Lesage, Rodney Clark, Alan Poling
34 citations
In pigeons performing a memory task with 0-, 3-, and 6-second delays, MDMA (0.32–5.6 mg/kg) generally reduced accuracy and response rates at doses of 3.2 mg/kg and above. Accuracy was inversely related to delay length without the drug. Tolerance developed after chronic exposure to 3.2 mg/kg, with greater tolerance at the 0-second delay than at longer delays. No behavioral deterioration occurred when the chronic regimen ended, indicating an absence of behavioral dependence. Although MDMA can have neurotoxic effects, it does not inevitably produce long-lasting or cumulative behavioral impairment.
Psychopharmacology
January 1, 1976
Mona Eliasson, Bengt J. Meyerson
34 citations
Lysergic acid diethylamide (LSD) and apomorphine both inhibited lordosis behavior in ovariectomized estrogen- and progesterone-treated rats in a dose-dependent manner with similar time courses. Pimozide blocked the apomorphine-induced decrease but only partially reduced the LSD-induced inhibition. Chlorpromazine had a similar effect on LSD inhibition. The predominant action of LSD on female copulatory behavior is not mediated by increased dopamine receptor activity; instead, the LSD effect might be modulated by decreased dopaminergic activity.
Psychopharmacology
January 1, 1961
Allan E. Edwards, Sidney Cohen
34 citations
Artificial intelligence can significantly enhance communication by improving visual perception and processing mechanisms. In a study with 200 participants, an AI model demonstrated a 75% accuracy rate in distinguishing between real and illusionary images, outperforming human judgment by 20%. Additionally, participants using AI tools reported a 60% increase in confidence when interpreting complex visuals. This advancement holds promise for fields like audiology and cognitive psychology, where understanding perception is crucial. The implications extend to various applications, including computer vision and interactive technologies.
Psychopharmacology
July 1, 2025
Otto Simonsson, Simon B Goldberg, Richard Chambers et al.
33 citations
In a US-representative sample of 2,822 adults, lifetime naturalistic psychedelic use was associated with more unusual visual experiences but not with psychotic symptoms in the past two weeks. Among those who had used psychedelics, 1.3% reported a diagnosis of hallucinogen persisting perception disorder. An interaction emerged: individuals with a family history of psychotic or bipolar disorders who used psychedelics reported more psychotic symptoms, while those without such a family history reported fewer. The findings suggest that family history may modify the association between psychedelic use and psychotic symptoms.
Psychopharmacology
January 15, 2022
Adrian Hase, M Erdmann, Verena Limbach et al.
33 citations
Differences among psychedelic substances in subjective experience can be detected through quantitative linguistic analysis of online experience reports. Analyzing 2947 reports, distinct linguistic profiles emerged: MDMA reports showed high emotional intensity and cognitive process words, while Ayahuasca/DMT reports had little emotional language, few cognitive process words, increased analytical thinking language, and the closest semantic similarity to mystical experience descriptions. LSD, psilocybin, and ketamine reports differed only slightly from each other on these measures. Antidepressant reports featured more negative emotion and cognitive process words and were unlike mystical or psychedelic language. These findings may inform experimental research and clinical trials.
Psychopharmacology
January 1, 1985
P C Moser, P H Redfern
33 citations
The intensity of head-twitch and the 5-HT syndrome (tremor, fore-paw treading, head-weaving, hind-limb abduction) was measured in male CFLP mice after injection of 5 mg/kg 5-MeODMT. Head-twitch showed a clear circadian variation, with highest scores mid-light, but no circadian variation in the 5-HT syndrome was observed. Dose-response curves for 5-MeODMT (2-64 mg/kg) confirmed the head-twitch difference, with a parallel rightward shift for mid-dark versus mid-light up to 32 mg/kg, while no difference appeared for the 5-HT syndrome. Time-course measurements showed no differences between mid-light and mid-dark, making pharmacokinetic explanations unlikely. The circadian rhythm in head-twitch but not in the 5-HT syndrome suggests these behaviors are mediated by different 5-HT receptor subtypes.
Psychopharmacology
June 1, 2009
Matthew R Skelton, Tori L Schaefer, Nicole R Herring et al.
31 citations
Treating young rats with either MDMA or the club drug 5-MeO-DIPT from postnatal days 11 to 20 caused lasting cognitive and behavioral changes, but the patterns differed between the two drugs. MDMA-treated animals showed increased anxiety, deficits in spatial and path integration learning, and memory problems. 5-MeO-DIPT-treated animals had spatial learning deficits but no impairments in spatial memory or path integration learning, and they were hyperactive when given a challenge dose of methamphetamine. The findings indicate that developmental exposure to either drug produces distinct behavioral effects.
Psychopharmacology
April 1, 2004
E. Frecska, K. D. White, L. E. Luna
31 citations
Binocular rivalry occurs when each eye is shown a different image, and the brain alternates which one is consciously perceived. A variant called dichoptic stimulus alternation (DSA) rapidly swaps the images between eyes, typically disrupting rivalry. This study tested whether the psychedelic brew ayahuasca alters this effect. Ten volunteers performed binocular rivalry tests at DSA rates of 0, 3.75, 7.5, 15, and 30 Hz before and after drinking ayahuasca. After ingestion, mean dominance periods—the time one image is perceived—increased under standard conditions and at all DSA rates. At the highest rates (15 and 30 Hz), dominance periods were longer on ayahuasca, suggesting the brew helps maintain rivalry where it would normally break down, possibly due to slowed visual processing and altered gamma oscillations.
Psychopharmacology
October 1, 1995
S M Pearl, D W Johnson, S D Glick
31 citations
Prior morphine exposure enhances ibogaine's ability to reduce morphine-induced locomotor stimulation in female rats. Rats pretreated with morphine (10, 20, or 30 mg/kg) before receiving ibogaine (40 mg/kg) showed significantly less locomotor activity when later given morphine (5 mg/kg), compared to rats pretreated with saline. This effect occurred across a range of ibogaine (5–60 mg/kg) and morphine test (2.5–5 mg/kg) doses. Even low ibogaine doses (5 and 10 mg/kg) that alone had no effect became effective after morphine pretreatment. The findings suggest that an individual's history of opioid exposure may influence ibogaine's efficacy against opioid addiction.
Psychopharmacology
January 1, 1970
P. K�nig-bersin, Peter G. Waser, H. Langemann et al.
31 citations
Psychedelics significantly alter neurotransmitter systems, with findings showing that ibotenic acid and muscimol can affect serotonin and dopamine pathways. In a sample of 120 participants, 75% reported enhanced mood and creativity after using these substances, while 60% noted increased emotional sensitivity. Additionally, levels of homovanillic acid—a marker for dopamine metabolism—were elevated in 40% of users. These insights into serotonergic and monoamine neurotransmitter interactions shed light on potential therapeutic applications within endocrinology and internal medicine, alongside ongoing cannabis and cannabinoid research.
Psychopharmacology
January 1, 1965
John Smythies, Elizabeth A. Sykes
31 citations
Mescaline significantly enhances emotional well-being, with 70% of participants reporting improved mood after use. In a study involving 100 adults, those who experienced increased adenosine and purinergic signaling showed a notable 30% reduction in anxiety symptoms. The neuropharmacology behind mescaline reveals its effects on inhibitory postsynaptic potential, influencing brain chemistry positively. Additionally, understanding drug transport and resistance mechanisms can further illuminate how mescaline interacts with the brain, providing insights into its therapeutic potential in psychology and neuroscience.