MDMA (3,4-Methylenedioxymethamphetamine) Analogues as Tools to Characterize MDMA-Like Effects: An Approach to Understand Entactogen Pharmacology

Treatment of Posttraumatic Stress Disorder: A State-of-the-art Review

This narrative state-of-the-art review paper describes the progress in the understanding and treatment of Posttraumatic Stress Disorder (PTSD). Over the last four decades, the scientific landscape has matured, with many interdisciplinary contributions to understanding its diagnosis, etiology, and epidemiology. Advances in genetics, neurobiology, stress pathophysiology, and brain imaging have made it apparent that chronic PTSD is a systemic disorder with high allostatic load. The current state of PTSD treatment includes a wide variety of pharmacological and psychotherapeutic approaches, of which many are evidence-based. However, the myriad challenges inherent in the disorder, such as individual and systemic barriers to good treatment outcome, comorbidity, emotional dysregulation, suicidality, dissociation, substance use, and trauma-related guilt and shame, often render treatment response suboptimal. These challenges are discussed as drivers for emerging novel treatment approaches, including early interventions in the Golden Hours, pharmacological and psychotherapeutic interventions, medication augmentation interventions, the use of psychedelics, as well as interventions targeting the brain and nervous system. All of this aims to improve symptom relief and clinical outcomes. Finally, a phase orientation to treatment is recognized as a tool to strategize treatment of the disorder, and position interventions in step with the progression of the pathophysiology. Revisions to guidelines and systems of care will be needed to incorporate innovative treatments as evidence emerges and they become mainstream. This generation is well-positioned to address the devastating and often chronic disabling impact of traumatic stress events through holistic, cutting-edge clinical efforts and interdisciplinary research.

MDMA-assisted therapy for moderate to severe PTSD: a randomized, placebo-controlled phase 3 trial

This multi-site, randomized, double-blind, confirmatory phase 3 study evaluated the efficacy and safety of 3,4-methylenedioxymethamphetamine-assisted therapy (MDMA-AT) versus placebo with identical therapy in participants with moderate to severe post-traumatic stress disorder (PTSD). Changes in Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) total severity score (primary endpoint) and Sheehan Disability Scale (SDS) functional impairment score (key secondary endpoint) were assessed by blinded independent assessors. Participants were randomized to MDMA-AT (n = 53) or placebo with therapy (n = 51). Overall, 26.9% (28/104) of participants had moderate PTSD, and 73.1% (76/104) of participants had severe PTSD. Participants were ethnoracially diverse: 28 of 104 (26.9%) identified as Hispanic/Latino, and 35 of 104 (33.7%) identified as other than White. Least squares (LS) mean change in CAPS-5 score (95% confidence interval (CI)) was -23.7 (-26.94, -20.44) for MDMA-AT versus -14.8 (-18.28, -11.28) for placebo with therapy (P < 0.001, d = 0.7). LS mean change in SDS score (95% CI) was -3.3 (-4.03, -2.60) for MDMA-AT versus -2.1 (-2.89, -1.33) for placebo with therapy (P = 0.03, d = 0.4). Seven participants had a severe treatment emergent adverse event (TEAE) (MDMA-AT, n = 5 (9.4%); placebo with therapy, n = 2 (3.9%)). There were no deaths or serious TEAEs. These data suggest that MDMA-AT reduced PTSD symptoms and functional impairment in a diverse population with moderate to severe PTSD and was generally well tolerated. ClinicalTrials.gov identifier: NCT04077437 .

Aromatic Bromination Abolishes Deficits in Visuospatial Learning Induced by MDMA ("Ecstasy") in Rats While Preserving the Ability to Increase LTP in the Prefrontal Cortex

It has recently been demonstrated that aromatic bromination at C(2) abolishes all typical psychomotor, and some key prosocial effects of the entactogen MDMA in rats. Nevertheless, the influence of aromatic bromination on MDMA-like effects on higher cognitive functions remains unexplored. In the present work, the effects of MDMA and its brominated analog 2Br-4,5-MDMA (1 mg/kg and 10 mg/kg i.p. each) on visuospatial learning, using a radial, octagonal Olton maze (4 × 4) which may discriminate between short-term and long-term memory, were compared with their influence on in vivo long-term potentiation (LTP) in the prefrontal cortex in rats. The results obtained indicate that MDMA diminishes both short- and long-term visuospatial memory but increases LTP. In contrast, 2Br-4,5-MDMA preserves long-term visuospatial memory and slightly accelerates the occurrence of short-term memory compared to controls, but increases LTP, like MDMA. Taken together, these data are consistent with the notion that the modulatory effects induced by the aromatic bromination of the MDMA template, which abolishes typical entactogenic-like responses, might be extended to those effects affecting higher cognitive functions, such as visuospatial learning. This effect seems not to be associated with the increase of LTP in the prefrontal cortex.

Lack of evidence for positive reinforcing and prosocial effects of MDMA in pair-housed male and female rats

3,4-Methylenedioxymethamphetamine (MDMA) is classified as an entactogen, producing feelings of emotional openness and relatedness. One unique feature of MDMA is that people tend to selectively take this drug in social and/or intimate situations. Although MDMA is recognized as having abuse liability, preclinical studies report that it has weak reinforcing effects in animals. The objective of this study was to characterize the positive reinforcing and prosocial effects of MDMA in a translational model of the social environment in which two rats have simultaneous and contingent access to MDMA in close physical proximity. To this end, MDMA self-administration was examined on both fixed and progressive ratio schedules of reinforcement in six groups of rats: (1) isolated males, (2) isolated females, (3) male-male dyads, (4) female-female dyads, (5) male-female dyads, and (6) female-male dyads. For pair-housed rats, data from both rats were analyzed. Next, social preferences were examined in a partner preference test. MDMA failed to produce positive reinforcing effects under all conditions examined. Across a 30-fold dose range (0.01-1.0 mg/kg/infusion), MDMA did not maintain higher responding than saline on both schedules of reinforcement and in all groups tested. In partner preference tests, a history of shared exposure to MDMA did not establish a social preference, and acute administration of MDMA failed to establish a preference for another MDMA-treated rat. These data suggest that social contact does not increase the positive reinforcing effects of MDMA in rats, and that neither contingent nor noncontingent MDMA administration establishes a social preference in rats.

Induced fit, ensemble binding space docking and Monte Carlo simulations of MDMA 'ecstasy' and 3D pharmacophore design of MDMA derivatives on the human serotonin transporter (hSERT)

The popular recreational drug MDMA (3,4-methylenedioxy-methamphetamine) has a documented potential as a psychopharmacological clinical and research tool. This is due to its unique ability to promote reprocessing of traumatic memories, empathetic and pro-social states. Although it is established that MDMA exerts its behavioural effects via the serotonin transporter (SERT), the ligand-protein molecular interplay remains elusive. In order to shed light on the binding of MDMA and its primary congeneric entactogens (MDA, MBDB and MDAI), we first combined induced fit with Monte Carlo simulations. The computed interaction energies of the models correlated well with experimental activities (_adjR² = 0.78). Then we carried out 'ensemble binding space docking' on trajectories generated by interpolation of experimentally derived structures of the hSERT from the outward-open, and the occluded, to the inward-open states. This approach revealed low-energy alternative binding modes, suggesting high occupancy of the central site, yet considerable MDMA mobility within it, favouring the paroxetine-like orientation. Finally, we designed a pharmacophore that may be used to recognise hSERT-mediated serotonin releasers and uptake inhibitors of diverse chemical structure, identifying their active conformations and interacting residues. We conclude that the conserved amine-Asp98 ionic and edge-to-face π-π interactions are crucial to the mode of action of MDMA on the hSERT, underscoring the contributions of Tyr95 and gating residues Phe341, Tyr176 and Phe335. Amenable to experimental testing, our modelling may aid the rational design of novel entactogenic compounds and contribute to the understanding of an action mechanism, common and typical of psychotropic agents.

A Systematic Review of the MDMA Model to Address Social Impairment in Autism

BACKGROUND

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterised by repetitive behaviours, cognitive rigidity/inflexibility, and social-affective impairment. Unfortunately, no gold-standard treatments exist to alleviate the core socio-behavioural impairments of ASD. Meanwhile, the prosocial empathogen/entactogen 3,4-methylene-dioxy-methamphetamine (MDMA) is known to enhance sociability and empathy in both humans and animal models of psychological disorders.

OBJECTIVE

We review the evidence obtained from behavioural tests across the current literature, showing how MDMA can induce prosocial effects in animals and humans, where controlled experiments were able to be performed.

METHODS

Six electronic databases were consulted. The search strategy was tailored to each database. Only English-language papers were reviewed. Behaviours not screened in this review may have affected the core ASD behaviours studied. Molecular analogues of MDMA have not been investigated.

RESULTS

We find that the social impairments may potentially be alleviated by postnatal administration of MDMA producing prosocial behaviours in mostly the animal model.

CONCLUSION

MDMA and/or MDMA-like molecules appear to be an effective pharmacological treatment for the social impairments of autism, at least in animal models. Notably, clinical trials based on MDMA use are now in progress. Nevertheless, larger and more extended clinical studies are warranted to prove the assumption that MDMA and MDMA-like molecules have a role in the management of the social impairments of autism.

Aromatic Bromination Abolishes the Psychomotor Features and Pro-social Responses of MDMA ("Ecstasy") in Rats and Preserves Affinity for the Serotonin Transporter (SERT)

The entactogen MDMA (3,4-methylenedioxy-methamphetamine, “Ecstasy”) exerts its psychotropic effects acting primarily as a substrate of the serotonin transporter (SERT) to induce a non-exocytotic release of serotonin. Nevertheless, the roles of specific positions of the aromatic ring of MDMA associated with the modulation of typical entactogenic effects, using analogs derived from the MDMA template, are still not fully understood. Among many possibilities, aromatic halogenation of the phenylalkylamine moiety may favor distribution to the brain due to increased lipophilicity, and sometimes renders psychotropic substances of high affinity for their molecular targets and high potency in humans. In the present work, a new MDMA analog brominated at C(2) of the aromatic ring (2-Br-4,5-MDMA) has been synthesized and pharmacologically characterized in vitro and in vivo. First, binding competition experiments against the SERT-blocker citalopram were carried out in human platelets and compared with MDMA. Besides, its effects on platelet aggregation were performed in platelet enriched human plasma using collagen as aggregation inductor. Second, as platelets are considered an appropriate peripheral model for estimating central serotonin availability, the functional effects of 2-Br-4,5-MDMA and MDMA on ATP release during human platelet aggregation were evaluated. The results obtained showed that 2-Br-4,5-MDMA exhibits higher affinity for SERT than MDMA and fully abolishes both platelet aggregation and ATP release, resembling the pharmacological profile of citalopram. Subsequent in vivo evaluation in rats at three dose levels showed that 2-Br-4,5-MDMA lacks all key MDMA-like behavioral responses in rats, including hyperlocomotion, enhanced active avoidance conditioning responses and increased social interaction. Taken together, the results obtained are consistent with the notion that 2-Br-4,5-MDMA should not be expected to be an MDMA-like substrate of SERT, indicating that aromatic bromination at C(2) modulates the pharmacodynamic properties of the substrate MDMA, yielding a citalopram-like compound.

(±)-MDMA and its enantiomers: potential therapeutic advantages of R(-)-MDMA

The use of (±)-3,4-methylenedioxymethamphetamine ((±)-MDMA) as an adjunct to psychotherapy in the treatment of psychiatric and behavioral disorders dates back over 50 years. Only in recent years have controlled and peer-reviewed preclinical and clinical studies lent support to (±)-MDMA's hypothesized clinical utility. However, the clinical utility of (±)-MDMA is potentially mitigated by a range of demonstrated adverse effects. One potential solution could lie in the individual S(+) and R(-) enantiomers that comprise (±)-MDMA. Individual enantiomers of racemic compounds have been employed in psychiatry to improve a drug's therapeutic index. Although no research has explored the individual effects of either S(+)-MDMA or R(-)-MDMA in humans in a controlled manner, preclinical research has examined similarities and differences between the two molecules and the racemic compound. This review addresses information related to the pharmacodynamics, neurotoxicity, physiological effects, and behavioral effects of S(+)-MDMA and R(-)-MDMA that might guide preclinical and clinical research. The current preclinical evidence suggests that R(-)-MDMA may provide an improved therapeutic index, maintaining the therapeutic effects of (±)-MDMA with a reduced side effect profile, and that future investigations should investigate the therapeutic potential of R(-)-MDMA.

The Toxicology of New Psychoactive Substances: Synthetic Cathinones and Phenylethylamines

BACKGROUND

New psychoactive substances (NPSs) are substitutes for classical drugs of abuse and there are now compounds available from all groups of classical drugs of abuse. During 2014, the number of synthetic cathinones increased dramatically and, together with phenylethylamines, they dominate the NPS markets in the European Union. In total, 31 cathinones and 9 phenylethylamines were encountered in 2014. The aim of this article was to summarize the existing knowledge about the basic pharmacology, metabolism, and human toxicology of relevant synthetic cathinones and phenylethylamines. Compared with existing reviews, we have also compiled the existing case reports from both fatal and nonfatal intoxications.

METHODS

We performed a comprehensive literature search using bibliographic databases PubMed and Web of Science, complemented with Google Scholar. The focus of the literature search was on original articles, case reports, and previously published review articles published in 2014 or earlier.

RESULTS

The rapid increase of NPSs is a growing concern and sets new challenges not only for societies in drug prevention and legislation but also in clinical and forensic toxicology. In vivo and in vitro studies have demonstrated that the pharmacodynamic profile of cathinones is similar to that of other psychomotor stimulants. Metabolism studies show that cathinones and phenylethylamines are extensively metabolized; however, the parent compound is usually detectable in human urine. In vitro studies have shown that many cathinones and phenylethylamines are metabolized by CYP2D6 enzymes. This indicates that these drugs may have many possible drug-drug interactions and that genetic polymorphism may influence their toxicity. However, the clinical and toxicological relevance of CYP2D6 in adverse effects of cathinones and phenylethylamines is questionable, because these compounds are metabolized by other enzymes as well. The toxidromes commonly encountered after ingestion of cathinones and phenylethylamines are mainly of sympathomimetic and hallucinogenic character with a risk of excited delirium and life-threatening cardiovascular effects.

CONCLUSIONS

The acute and chronic toxicity of many NPSs is unknown or very sparsely investigated. There is a need for evidence-based-treatment recommendations for acute intoxications and a demand for new strategies to analyze these compounds in clinical and forensic cases.

Constructing the ecstasy of MDMA from its component mental organs: Proposing the primer/probe method

The drug MDMA, commonly known as ecstasy, produces a specific and distinct open hearted mental state, which led to the creation of a new pharmacological class, "entactogens". Extensive literature on its mechanisms of action has come to characterize MDMA as a "messy" drug with multiple mechanisms, but the consensus is that the distinctive entactogenic effects arise from the release of neurotransmitters, primarily serotonin. I propose an alternative hypothesis: The entactogenic mental state is due to the simultaneous direct activation of imidazoline-1 (I1) and serotonin-2 (5-HT2) receptors by MDMA. This hypothesis emerges from "mental organ" theory, which embodies many hypotheses, the most relevant of which are: "Mental organs" are populations of neurons that all express their defining metabotropic receptor, and each mental organ plays a distinct role in the mind, a role shaped by evolution as mental organs evolve by duplication and divergence. Mental organs are the mechanism by which evolution sculpts the mind. Mental organs can be in or out of consciousness. In order for a mental organ to enter consciousness, three things must happen: The mental organ must be activated directly at its defining receptor. 5-HT2 must be simultaneously activated. One of the functions of activated 5-HT2 is to load other simultaneously activated mental organs fully into consciousness. In some cases THC must be introduced to remove long-term blocks mediated by the cannabinoid system. I propose the "primer/probe" method to test these hypotheses. A "primer" is a drug that selectively activates 5-HT2 (e.g. DOB or MEM) or serotonin-1 (5-HT1) and 5-HT2 (e.g. DOET or 2C-B-fly). A "probe" is a drug that activates a receptor whose corresponding mental organ we wish to load into consciousness in order to understand its role in the mind. The mental organ is loaded into consciousness when the primer and probe are taken together, but not when taken separately. For example, the blood pressure medications rilmenidine and moxonidine are selective for imidazoline-1 and can be used to test the hypothesis that the entactogenic mental effects of MDMA are due to loading the imidazoline-1 mental organ into consciousness. The primer/probe method is not limited to testing the specific hypothesis about MDMA and imidazoline, but is a general method for studying the role of mental organs in the mind. For example, the role of dopamine mental organs can be studied by using Parkinson's drugs such as ropinirole or pramipexole as probes.

Acute Effects of the Novel Psychoactive Drug 2C-B on Emotions

Background. 2C-B (Nexus) is one of the most widespread novel psychoactive substances. There is limited information about its pharmacological properties, and few studies in humans concern its acute and chronic effects. 2C-B has been classified as a stimulant, hallucinogen, entactogen, and/or empathogen. Objectives. To evaluate the emotional, subjective, and cardiovascular effects of 2C-B. Methods. Twenty healthy recreational 2C-B users (12 women) self-administered a 20 mg dose of 2C-B. Evaluations included emotional (IAPS, FERT, and speech), subjective (visual analog scales, ARCI, VESSPA, HRS, and POMS questionnaires), and cardiovascular effects (blood pressure and heart rate). Results. Positive subjective effects predominated with a reduction of anger under the influence of 2C-B. It did, however, increase reactivity to negative emotional stimuli and decrease the ability to recognize expressions of happiness. Augmented emotionality in speech could be appreciated by others. 2C-B induced euphoria and well-being, changes in perceptions, and slight hallucinogenic states. Mild sympathetic actions were observed. Conclusions. The specific profile that 2C-B exerts on emotions suggests its classification as an entactogen with psychedelic properties.