'Ecstasy' as a social drug: MDMA preferentially affects responses to emotional stimuli with social content

Social homeostasis and psychoactive drugs: What can we learn from opioid and amphetamine drug challenge studies in humans?

BACKGROUND

Social disequilibrium, or disrupted social homeostasis, underlies many behavioral disorders, including problematic drug use. One way to study the relationship between drug use and social homeostasis is to determine whether single doses of psychoactive drugs relieve some of the discomfort of social isolation and promote social connection.

METHODS

In this narrative review, we discuss challenges and opportunities in studying the relationship between psychoactive drugs and social homeostasis. Using the examples of opioids and amphetamines, we discuss the evidence that drugs alleviate dysphoria related to lack of social connection or produce pro-social effects that improve connection.

RESULTS

With regard to opioid drugs, we report that mu opioid agonists and kappa opioid antagonists reduce distress from social isolation, and mu opioid agonists enhance social reward. Amphetamine-like stimulant drugs, including MDMA, do not seem to act by reducing the distress of social isolation, but they have notable prosocial effects that increase both motivation for social contact and the pleasure derived from interacting socially.

CONCLUSIONS

Many questions remain in understanding interactions between drugs and social equilibrium, including whether these effects contribute to problematic drug use. We identify gaps in knowledge, including the effects of drug withdrawal or dependence on social function, or the responses of individuals with psychiatric symptomatology. Understanding these actions on social processes will help to develop novel pharmacologic treatments for clinical problems related to social disequilibrium.

Antidepressant and anxiolytic effects of activating 5HT2A receptors in the anterior cingulate cortex and the theoretical mechanisms underlying them - A scoping review of available literature

Psychedelic drugs that activate the 5HT2A receptor have long been the target of extensive clinical research, particularly in models of psychiatric illness. The aim of this literature review was to investigate the therapeutic effects of 5HT2A receptor activation in the anterior cingulate cortex (ACC) and the respective mechanisms that underlie them. Based on the available research, I suggest that 5HT2A receptors in the ACC exert profound changes in excitatory neurotransmission and brain network connectivity in a way that reduces anxious preoccupation and obsessional thoughts, as well as promoting cognitive flexibility and long-lasting mood improvements in anhedonia. This is possibly due to a complex interplay with glutamate and gamma-butyric acid neurotransmission, particularly 5HT2A activation enhances α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor signalling, thus altering the ratio of AMPA to N-methyl-D-Aspartate (NMDA) activity in the ACC, which can dismantle previously established neuronal connections and aid the formation of new ones, an effect that may be beneficial for fear extinction and reversal learning. Psychedelics potentially change intra- and internetwork connectivity, strengthening connectivity from the dorsal ACC / Salience Network to the Default Mode Network (DMN) and Central Executive Network (CEN), which correlates with improvements in attentional shifting and anti-anhedonic effects. Additionally, they may decrease inhibitory influence of the DMN over the CEN which may reduce overevaluation of internal states and ameliorate cognitive deficits. Activation of ACC 5HT2A receptors also has important downstream effects on subcortical areas, including reducing amygdala reactivity to threatening stimuli and enhancing mesolimbic dopamine, respectively improving anxiety and the experience of natural rewards.

Psychedelics as a tool for a more connected and sustainable world? Considering the importance of rituals, boundaries, and commitment

Despite the surge of interest in psychedelic research in the past decade, largely due to the promise of psychedelics for improving mental health outcomes, there has been comparatively little discussion about the social and environmental consequences of psychedelic drug use. While there is growing evidence to suggest psychedelics could foster a greater connection to the natural world and improve social relationships, such positive repercussions are far from guaranteed. In this commentary, we focus on LSD, psilocybin and especially MDMA, and outline three insights we came to see as crucial to creating beneficial outcomes: 1) the importance of setting and rituals, 2) the establishment of boundaries, and 3) understanding the long-term commitment required. These insights are grounded in the history of psychedelics, which is intimately intertwined with ritualised use, yet the process of commercialisation of these substances threatens to strip away important contextual factors. Creating boundaries around when, how and with whom psychedelics are used have been found to protect recreational users from harm and could also be instrumental in steering commercial interests to align with socio-environmental goals. Finally, far from being a 'quick fix' for social or environmental problems, the use of psychedelics requires sustained engagement to integrate the insights obtained. Whereas we remain optimistic about the transformative potential of psychedelics for social relationships and the environment, we also emphasise the need for a more cautious, considered approach if we are to harness the benefits and minimise the challenges of psychedelic drug use.

Physical activity promotes brain development through serotonin during early childhood

Early childhood serves as a critical period for neural development and skill acquisition when children are extremely susceptible to the external environment and experience. As a crucial experiential stimulus, physical activity is believed to produce a series of positive effects on brain development, such as cognitive function, social-emotional abilities, and psychological well-being. The World Health Organization recommends that children engage in sufficient daily physical activity, which has already been strongly advocated in the practice of preschool education. However, the mechanisms by which physical activity promotes brain development are still unclear. The role of neurotransmitters, especially serotonin, in promoting brain development through physical activity has received increasing attention. Physical activity has been shown to stimulate the secretion of serotonin by increasing the bioavailability of free tryptophan and enriching the diversity of gut microbiota. Due to its important role in modulating neuronal proliferation, differentiation, synaptic morphogenesis, and synaptic transmission, serotonin can regulate children's explicit cognitive and social interaction behavior in the early stages of life. Therefore, we hypothesized that serotonin emerges as a pivotal transmitter that mediates the relationship between physical activity and brain development during early childhood. Further systematic reviews and meta-analyses are needed to specifically explore whether the type, intensity, dosage, duration, and degree of voluntariness of PA may affect the role of serotonin in the relationship between physical activity and brain function. This review not only helps us understand the impact of exercise on development but also provides a solid theoretical basis for increasing physical activity during early childhood.

The 3,4-methylenedioxymethamphetamine enhances early visual processing for salient socio-emotional stimuli

The 3,4-methylenedioxymethamphetamine (MDMA) has long been used non-medically, and it is currently under investigation for its potential therapeutic benefits. Both uses may be related to its ability to enhance empathy, sociability, emotional processing and its anxiolytic effects. However, the neural mechanisms underlying these effects, and their specificity to MDMA compared to other stimulants, are not yet fully understood. Here, using electroencephalography (EEG), we investigated the effects of MDMA and a prototypic stimulant, methamphetamine (MA), on early visual processing of socio-emotional stimuli in an oddball emotional faces paradigm. Specifically, we examined whether MDMA or MA enhance the processing of facial expressions, compared to placebo, during the early stages of visual perception. MDMA enhanced an event-related component that is sensitive to detecting faces (N170), specifically for happy and angry expressions compared to neutral faces. MA did not affect this measure, and neither drug altered other components of the response to emotional faces. These findings provide novel insights into the neural mechanisms underlying the effects of MDMA on socio-emotional processing and may have implications for the therapeutic use of MDMA in the treatment of social anxiety and other psychiatric disorders.

The Psychedelic Future of Post-Traumatic Stress Disorder Treatment

Post-traumatic stress disorder (PTSD) is a mental health condition that can occur following exposure to a traumatic experience. An estimated 12 million U.S. adults are presently affected by this disorder. Current treatments include psychological therapies (e.g., exposure-based interventions) and pharmacological treatments (e.g., selective serotonin reuptake inhibitors (SSRIs)). However, a significant proportion of patients receiving standard-of-care therapies for PTSD remain symptomatic, and new approaches for this and other trauma-related mental health conditions are greatly needed. Psychedelic compounds that alter cognition, perception, and mood are currently being examined for their efficacy in treating PTSD despite their current status as Drug Enforcement Administration (DEA)- scheduled substances. Initial clinical trials have demonstrated the potential value of psychedelicassisted therapy to treat PTSD and other psychiatric disorders. In this comprehensive review, we summarize the state of the science of PTSD clinical care, including current treatments and their shortcomings. We review clinical studies of psychedelic interventions to treat PTSD, trauma-related disorders, and common comorbidities. The classic psychedelics psilocybin, lysergic acid diethylamide (LSD), and N,N-dimethyltryptamine (DMT) and DMT-containing ayahuasca, as well as the entactogen 3,4-methylenedioxymethamphetamine (MDMA) and the dissociative anesthetic ketamine, are reviewed. For each drug, we present the history of use, psychological and somatic effects, pharmacology, and safety profile. The rationale and proposed mechanisms for use in treating PTSD and traumarelated disorders are discussed. This review concludes with an in-depth consideration of future directions for the psychiatric applications of psychedelics to maximize therapeutic benefit and minimize risk in individuals and communities impacted by trauma-related conditions.

Can research on entactogens contribute to a deeper understanding of human sexuality?

In recent years, scientific research into the therapeutic potential of psychedelic compounds has experienced a resurgence of interest. New studies have shown promising results, supporting the use of psychedelic drugs in treating various psychiatric disorders, including treatment-resistant depression, post-traumatic stress disorder, and even alcohol addiction. The FDA has recognized 3,4-methylenedioxymethamphetamine (MDMA) as a breakthrough therapy to treat symptoms of post-traumatic stress disorder. At the same time, interviews with recreational MDMA users have documented experiences of emotional intimacy while using MDMA, often without the desire for penetrative sex. However, some people have reported that MDMA increases their sexual arousal and specifically use it to enhance their sexual performance. This study aims to analyze current and planned research on the psychophysiological effects of entactogens on human sexuality. With their prosocial potential, the pharmacokinetic and neuroendocrine effects of entactogens may recreate the subjective experience of emotional intimacy, the initiation of intimate relationships, or even feelings of 'falling in love' with previously neutral individuals while under the influence of entactogens. This includes MDMA-induced sexual arousal-like effects observed through subjective behavioral perceptions of desire and arousal and specific physiological markers such as oxytocin and prolactin. Modern MDMA-assisted psychotherapy (MDMA-AP) protocols are transparent and follow strict ethical guidelines. However, despite these proposed ethical principles, little consideration has been given to the potential neurobehavioral effects of entactogens on the sexuality of participants in MDMA-AP protocols. The psychophysiological and sexual effects of entactogens should be discussed more openly in current MDMA-AP protocols, including the potential experience of the phenomenon of sexualized pharmacotransference.

Examining associations between MDMA/ecstasy and classic psychedelic use and impairments in social functioning in a U.S. adult sample

Impairment in social functioning is a common source of morbidity across many mental health disorders, yet there is a dearth of effective and easily implemented interventions to support social functioning. MDMA/ecstasy and classic psychedelics (psilocybin, LSD, peyote, mescaline) represent two potential treatments for impairments in social functioning, as evidence suggests these compounds may be supportive for alleviating social difficulties. Using a nationally representative sample of U.S. adults from the National Survey on Drug Use and Health (2015-2019) (N = 214,505), we used survey-weighted multivariable ordinal and logistic regression to examine the associations between lifetime use of the aforementioned compounds and impairments in social functioning in the past year. Lifetime MDMA/ecstasy use was associated with lowered odds of three of our four social impairment outcomes: difficulty dealing with strangers (aOR 0.92), difficulty participating in social activities (aOR 0.90), and being prevented from participating in social activities (aOR 0.84). Lifetime mescaline use was also associated with lowered odds of difficulty dealing with strangers (aOR 0.85). All other substances either shared no relationship with impairments in social functioning or conferred increased odds of our outcomes. Future experimental studies can assess whether these relationships are causal.

Potential processes of change in MDMA-Assisted therapy for social anxiety disorder: Enhanced memory reconsolidation, self-transcendence, and therapeutic relationships

OBJECTIVE

Researchers have suggested that psychotherapy may be enhanced by the addition of 3,4-methylenedioxymethamphetamine (MDMA), particularly in the treatment of disorders wherein interpersonal dysfunction is central, such as social anxiety disorder. We review literature pertaining to three potential processes of change that may be instigated during sessions involving MDMA administration in the treatment of social anxiety disorder.

DESIGN

This is a narrative review that integrates research on the etiology and maintenance of social anxiety disorder and mechanisms of action of MDMA to examine how MDMA may enhance psychotherapy outcomes.

RESULTS

We first outline how MDMA may enhance memory reconsolidation in social anxiety disorder. We then discuss how MDMA may induce experiences of self-transcendence and self-transcendent emotions such as compassion, love, and awe; and how these experiences may be therapeutic in the context of social anxiety disorder. We subsequently discuss the possibility that MDMA may enhance the strength and effectiveness of the therapeutic relationship which is a robust predictor of outcomes across many disorders as well as a potential key ingredient in treating disorders where shame and social disconnection are central factors.

CONCLUSION

We discuss how processes of change may extend beyond the MDMA dosing sessions themselves.

Challenges in translational research: MDMA in the laboratory versus therapeutic settings

Despite substantial progress in the use of mind-altering drugs to treat psychiatric disorders, the psychological processes through which these drugs change mood or behavior are poorly understood. Controlled laboratory studies with well-defined psychological constructs are valuable to understand how these drugs manifest their therapeutic benefit. However, there are substantial methodological differences between clinical studies investigating therapeutic outcome and laboratory studies investigating the processes that might underlie the therapeutic effects. Here, we examine some of these differences using the example of 3,4-methylenedioxymethamphetamine (MDMA). We review differences in expectancies, social and physical context, participant characteristics, pharmacological factors, and outcome measures in studies with participants who do or do not have psychiatric diagnoses. We describe the challenges and opportunities in translating findings from laboratory studies to the clinic and identify ways to bridge the gap between these approaches.

A proposed mechanism for the MDMA-mediated extinction of traumatic memories in PTSD patients treated with MDMA-assisted therapy

Post-traumatic stress disorder (PTSD) is a devastating psychiatric disorder afflicting millions of people around the world. Characterized by severe anxiety, intrusive thoughts, pervasive nightmares, an assortment of somatic symptoms, associations with severe long-term health problems, and an elevated risk of suicide, as much as 40-70% of patients suffer from refractory disease. 3,4-Methylenedioxy-methamphetamine (MDMA), like classic psychedelics such as psilocybin, have been used to enhance the efficacy of psychotherapy almost since their discovery, but due to their perceived potential for abuse and inclusion on USFDA (United States Food and Drug Administration) schedule 1, research into the mechanism by which they produce improvements in PTSD symptomology has been limited. Nevertheless, several compelling rationales have been explored, with the pro-social effects of MDMA thought to enhance therapeutic alliance and thus facilitate therapist-assisted trauma processing. This may be insufficient to fully explain the efficacy of MDMA in the treatment of psychiatric illness. Molecular mechanisms such as the MDMA mediated increase of brain-derived neurotrophic factor (BDNF) availability in the fear memory learning pathways combined with MDMA's pro-social effects may provide a more nuanced explanation for the therapeutic actions of MDMA.

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.

Detection of acute 3,4-methylenedioxymethamphetamine (MDMA) effects across protocols using automated natural language processing

The detection of changes in mental states such as those caused by psychoactive drugs relies on clinical assessments that are inherently subjective. Automated speech analysis may represent a novel method to detect objective markers, which could help improve the characterization of these mental states. In this study, we employed computer-extracted speech features from multiple domains (acoustic, semantic, and psycholinguistic) to assess mental states after controlled administration of 3,4-methylenedioxymethamphetamine (MDMA) and intranasal oxytocin. The training/validation set comprised within-participants data from 31 healthy adults who, over four sessions, were administered MDMA (0.75, 1.5 mg/kg), oxytocin (20 IU), and placebo in randomized, double-blind fashion. Participants completed two 5-min speech tasks during peak drug effects. Analyses included group-level comparisons of drug conditions and estimation of classification at the individual level within this dataset and on two independent datasets. Promising classification results were obtained to detect drug conditions, achieving cross-validated accuracies of up to 87% in training/validation and 92% in the independent datasets, suggesting that the detected patterns of speech variability are associated with drug consumption. Specifically, we found that oxytocin seems to be mostly driven by changes in emotion and prosody, which are mainly captured by acoustic features. In contrast, mental states driven by MDMA consumption appear to manifest in multiple domains of speech. Furthermore, we find that the experimental task has an effect on the speech response within these mental states, which can be attributed to presence or absence of an interaction with another individual. These results represent a proof-of-concept application of the potential of speech to provide an objective measurement of mental states elicited during intoxication.

Aggression in the Australian night time economy: A comparison of alcohol only versus alcohol and illicit drug consumption

INTRODUCTION AND AIMS

Associations between substance use and aggression may be amplified by simultaneous alcohol and illicit drug use. This study aims to compare differences in involvement in past aggression between people who use different substances while accounting for broader risk propensity.

DESIGN AND METHODS

Self-reported data on past three-month involvement in verbal and physical aggression (victim or perpetrator) were drawn from interviews conducted in night-time entertainment districts in seven Australian cities (n = 5078). Using inverse probability of treatment weighting techniques, participants who reported alcohol versus alcohol and illicit drug use on the night of interview (including ecstasy, cannabis and other illicit stimulant subgroups) were weighted on the basis of drug use risk covariates (e.g. alcohol consumed, gender) to determine differences in involvement in aggression involvement.

RESULTS

After weighting for covariates, individuals who reported consuming any illicit drug + alcohol and ecstasy + alcohol combinations were more likely to be involved in physical (33% and 105%, respectively) and verbal (36% and 116%, respectively) aggression in the previous 3-months when compared to those who consumed alcohol only. Cannabis + alcohol and other illicit stimulant + alcohol combinations were no more likely to be involved in either forms of aggression.

DISCUSSION AND CONCLUSIONS

The likelihood of having been involved in past aggressive incidents was higher among those who reported any illicit drug + alcohol and ecstasy + alcohol combinations than those who reported alcohol exclusively, after accounting for covariates. These findings highlight individuals that may benefit most from the development of tailored health promotion/preventative safety interventions in night-time settings.

Effects of MDMA on attention to positive social cues and pleasantness of affective touch

The psychostimulant drug ±3,4-methylenedioxymethamphetamine (MDMA) reportedly produces distinctive feelings of empathy and closeness with others. MDMA increases social behavior in animal models and has shown promise in psychiatric disorders, such as autism spectrum disorder (ASD) and post-traumatic stress disorder (PTSD). How it produces these prosocial effects is not known. This behavioral and psychophysiological study examined the effects of MDMA, compared with the prototypical stimulant methamphetamine (MA), on two measures of social behavior in healthy young adults: (i) responses to socially relevant, "affective" touch, and (ii) visual attention to emotional faces. Men and women (N = 36) attended four sessions in which they received MDMA (0.75 or 1.5 mg/kg), MA (20 mg), or a placebo in randomized order under double-blind conditions. Responses to experienced and observed affective touch (i.e., being touched or watching others being touched) were assessed using facial electromyography (EMG), a proxy of affective state. Responses to emotional faces were assessed using electrooculography (EOG) in a measure of attentional bias. Subjective ratings were also included. We hypothesized that MDMA, but not MA, would enhance the ratings of pleasantness and psychophysiological responses to affective touch and increase attentional bias toward positive facial expressions. Consistent with this, we found that MDMA, but not MA, selectively enhanced ratings of pleasantness of experienced affective touch. Neither drug altered the ratings of pleasantness of observed touch. On the EOG measure of attentional bias, MDMA, but not MA, increased attention toward happy faces. These results provide new evidence that MDMA can enhance the experience of positive social interactions; in this case, pleasantness of physical touch and attentional bias toward positive facial expressions. The findings are consistent with evidence that the prosocial effects are unique to MDMA relative to another stimulant. Understanding the behavioral and neurobiological processes underlying the distinctive social effects of MDMA is a key step to developing the drug for psychiatric disorders.

In the face of stress: Interpreting individual differences in stress-induced facial expressions

Stress is an inevitable part of life that can profoundly impact social and emotional functioning, contributing to the development of psychiatric disease. One key component of emotion and social processing is facial expressions, which humans can readily detect and react to even without conscious awareness. Facial expressions have been the focus of philosophic and scientific interest for centuries. Historically, facial expressions have been relegated to peripheral indices of fixed emotion states. More recently, affective neuroscience has undergone a conceptual revolution, resulting in novel interpretations of these muscle movements. Here, we review the role of facial expressions according to the leading affective neuroscience theories, including constructed emotion and social-motivation accounts. We specifically highlight recent data (Mayo et al, 2018) demonstrating the way in which stress shapes facial expressions and how this is influenced by individual factors. In particular, we focus on the consequence of genetic variation within the endocannabinoid system, a neuromodulatory system implicated in stress and emotion, and its impact on stress-induced facial muscle activity. In a re-analysis of this dataset, we highlight how gender may also influence these processes, conceptualized as variation in the "fight-or-flight" or "tend-and-befriend" behavioral responses to stress. We speculate on how these interpretations may contribute to a broader understanding of facial expressions, discuss the potential use of facial expressions as a trans-diagnostic marker of psychiatric disease, and suggest future work necessary to resolve outstanding questions.

Serotonergic hallucinogens and recognition of facial emotion expressions: a systematic review of the literature

BACKGROUND

Recognition of emotions in facial expressions (REFE) is a key aspect of social cognition. Anxiety and mood disorders are associated with deficits in REFE, and anxiolytics and antidepressants reverse these deficits. Recent studies have shown that serotonergic hallucinogens (i.e. ayahuasca, dimethyltryptamine, psilocybin, lysergic acid diethylamide [LSD], and mescaline) have anxiolytic and antidepressant properties, but their effects on REFE are not well understood. The purpose of the study was to conduct a systematic review analyzing the effects of serotonergic hallucinogens on REFE in humans.

METHODS

Studies published in the PubMed, PsycINFO, and Web of Science databases until 19 October 2018 which analyzed the effects of serotonergic hallucinogens on REFE in humans were included.

RESULTS

Of the 62 studies identified, 8 studies were included. Included studies involved the administration of a single or a few doses of LSD or psilocybin, and most trials were randomized and controlled with placebo. LSD and psilocybin reduced the recognition of negative emotions in most studies and modulated amygdala activity to these stimuli, which was correlated with antidepressive effects in patients. Both drugs were well tolerated.

CONCLUSIONS

Serotonergic hallucinogens reduced the recognition of negative emotions by modulating amygdala activity. Despite the small sample sizes, results suggest that serotonergic hallucinogens show promising beneficial effects on deficits in REFE.

Regular MDMA use is associated with decreased risk of drug injection among street-involved youth who use illicit drugs

OBJECTIVES

Childhood trauma is common among street-involved youth and is associated with injection drug use. Illicit 3,4-Methylenedioxymethamphetamine (MDMA) use is also common among street-involved youth, and data suggest this substance has clinical utility in management of post-traumatic stress disorder (PTSD) and associated harms. Despite this, little is known about co-occurring patterns of MDMA use and injection drug use.

METHODS

Data were derived from a prospective cohort of street-involved youth using illicit drugs in Vancouver, Canada. Using multivariable generalized estimating equation logistic regression, we examined the association between MDMA use and the use of injection drugs, adjusting for confounders such as polysubstance use and sociodemographic factors.

RESULTS

4941 surveys from 1208 participants between September 2005 and May 2015 were included. Of these, 829 (68.6%) were male, 815 (67.5%) reported white ethnicity, and median age was 21.7 years. Overall, 599 (49.6%) participants reported MDMA use, 544 (45.0%) reported injection drug use, and 244 (20.2%) reported concurrent MDMA and injection drug use at least once during the study period. In multivariable analyses, regular MDMA use was significantly negatively associated with injection drug use (Adjusted Odds Ratio [AOR] = 0.57, 95% CI: 0.46-0.69).

DISCUSSION

After accounting for socio-demographic factors and polysubstance use, periods of reported regular MDMA use were negatively associated with reported injection drug use among this cohort. These findings suggest that, unlike the use of most other non-injection drugs, illicit MDMA use does not appear to promote injection drug use but rather is associated with a reduced likelihood of injection drug use.

Positive psychology in the investigation of psychedelics and entactogens: A critical review

RATIONALE

We reviewed the concepts and empirical findings in studies with psychedelics and entactogens related to positive psychology - the study of healthy human functioning, well-being and eudaemonia. It is an unresolved question how beneficial effects of psychedelics and entactogens are related to the potential risks of these substances - particularly in non-clinical settings.

METHODS

We searched in PubMed, PsychINFO and the Cochrane Library for controlled clinical and epidemiological studies which applied concepts from positive psychology. We included N = 77 eligible studies with 9876 participants published before November 1st, 2017: (1) quantitative studies (N = 54), (2) preliminary or exploratory studies and reviews not including meta-analyses (N = 17), and (3) studies evidencing primarily negative results (N = 6).

RESULTS

Positive psychology concepts have been applied for measuring effects of clinical trials, recreational and ceremonial use of psychedelics and entactogens. Psychedelics and entactogens were shown to produce acute and long-term effects on mood, well-being, prosocial behaviours, empathy, cognitive flexibility, creativity, personality factors like openness, value orientations, nature-relatedness, spirituality, self-transcendence and mindfulness-related capabilities.

CONCLUSIONS

There is preliminary evidence for beneficial effects of psychedelics and entactogens on measures of positive psychology in clinical and healthy populations, however their sustainability remains largely unresolved. The reported results must be considered preliminary due to methodological restrictions. Since longitudinal data on both positive and adverse effects of psychedelics are lacking, more rigorous and standardized measures from positive psychology should be applied in less biased populations with prospective longitudinal designs to carefully assess the benefit-risk-ratio. This article is part of the Special Issue entitled 'Psychedelics: New Doors, Altered Perceptions'.

Oxytocin receptor gene variations and socio-emotional effects of MDMA: A pooled analysis of controlled studies in healthy subjects

Methylenedioxymethamphetamine (MDMA) increases oxytocin, empathy, and prosociality. Oxytocin plays a critical role in emotion processing and social behavior and has been shown to mediate the prosocial effects of MDMA in animals. Genetic variants, such as single-nucleotide polymorphisms (SNPs), of the oxytocin receptor (OXTR) may influence the emotional and social effects of MDMA in humans. The effects of common genetic variants of the OXTR (rs53576, rs1042778, and rs2254298 SNPs) on the emotional, empathogenic, and prosocial effects of MDMA were characterized in up to 132 healthy subjects in a pooled analysis of eight double-blind, placebo-controlled studies. In a subset of 53 subjects, MDMA produced significantly greater feelings of trust in rs1042778 TT genotypes compared with G allele carriers. The rs53576 and rs225498 SNPs did not moderate the subjective effects of MDMA in up to 132 subjects. None of the SNPs moderated MDMA-induced impairments in negative facial emotion recognition or enhancements in emotional empathy in the Multifaceted Empathy Test in 69 subjects. MDMA significantly increased plasma oxytocin concentrations. MDMA and oxytocin concentrations did not differ between OXTR gene variants. The present results provide preliminary evidence that OXTR gene variations may modulate aspects of the prosocial subjective effects of MDMA in humans. However, interpretation should be cautious due to the small sample size. Additionally, OXTR SNPs did not moderate the subjective overall effect of MDMA (any drug effect) or feelings of “closeness to others”.

Trial registration: ClinicalTrials.gov: http://www.clinicaltrials.gov, No: NCT00886886, NCT00990067, NCT01136278, NCT01270672, NCT01386177, NCT01465685, NCT01771874, and NCT01951508.

Psilocybin and MDMA reduce costly punishment in the Ultimatum Game

Disruptions in social decision-making are becoming evident in many psychiatric conditions. These are studied using paradigms investigating the psychological mechanisms underlying interpersonal interactions, such as the Ultimatum Game (UG). Rejection behaviour in the UG represents altruistic punishment – the costly punishment of norm violators – but the mechanisms underlying it require clarification. To investigate the psychopharmacology of UG behaviour, we carried out two studies with healthy participants, employing serotonergic agonists: psilocybin (open-label, within-participant design, N = 19) and 3,4-methylenedioxymethamphetamine (MDMA; placebo-controlled, double-blind, crossover design, N = 20). We found that both MDMA and psilocybin reduced rejection of unfair offers (odds ratio: 0.57 and 0.42, respectively). The reduction in rejection rate following MDMA was associated with increased prosociality (R² = 0.26, p = 0.025). In the MDMA study, we investigated third-party decision-making and proposer behaviour. MDMA did not reduce rejection in the third-party condition, but produced an increase in the amount offered to others (Cohen’s d = 0.82). We argue that these compounds altered participants’ conceptualisation of ‘social reward’, placing more emphasis on the direct relationship with interacting partners. With these compounds showing efficacy in drug-assisted psychotherapy, these studies are an important step in the further characterisation of their psychological effects.

Considering the context: social factors in responses to drugs in humans

BACKGROUND

Drugs are typically used in social settings. Here, we consider two factors that may contribute to this observation: (i) the presence of other people may enhance the positive mood effects of a drug, and conversely, (ii) drugs may enhance the value of social stimuli.

METHODS

We review evidence from controlled laboratory studies with human volunteers, which investigated either of these interactions between social factors and responses to drugs. We examine the bidirectional effects of social stimuli and single doses of alcohol, stimulants, opioids, and cannabis.

RESULTS

All four classes of drugs interact with social contexts, but the nature of these interactions varies across drugs, and depends on whether the context is positive or negative.

CONCLUSIONS

Alcohol and stimulant drugs enhance the attractiveness of social stimuli and the desire to socialize, and social contexts, in turn, enhance these drugs' effects. In contrast, opioids and cannabis have subtler effects on social interactions and their effects are less influenced by the presence of others. Overall, there is stronger evidence that drugs enhance positive social contexts than that they dampen the negativity of unpleasant social settings. Controlled research is needed to understand the interactions between drugs of abuse and social contexts, to model and understand the determinants of drug use outside the laboratory.

No major role of norepinephrine transporter gene variations in the cardiostimulant effects of MDMA

Purpose

Methylenedioxymethamphetamine (MDMA, ecstasy) is used recreationally and frequently leads to sympathomimetic toxicity. MDMA produces cardiovascular and subjective stimulant effects that were shown to partially depend on the norepinephrine transporter (NET)-mediated release of norepinephrine and stimulation of α₁-adrenergic receptors. Genetic variants, such as single-nucleotide polymorphisms (SNPs), of the NET gene (SLC6A2) may explain interindividual differences in the acute stimulant-type responses to MDMA in humans.

Methods

We characterized the effects of common genetic variants of the SLC6A2 gene (rs168924, rs47958, rs1861647, rs2242446, and rs36029) on cardiovascular and subjective stimulation after MDMA administration in 124 healthy subjects in a pooled analysis of eight double-blind, placebo-controlled studies.

Results

Carriers of the GG genotype of the SLC6A2 rs1861647 SNP presented higher elevations of heart rate and rate-pressure product after MDMA than subjects with one or no G alleles. Subjects with a C allele in the SLC6A2 rs2242446 SNP presented higher elevations of the heart rate after MDMA administration compared with the TT genotype. Subjects with the AA genotype of the SLC6A2 rs36029 SNP presented higher elevations of mean arterial pressure and rate pressure product after MDMA administration than carriers of the G allele. The SLC6A2 rs168924 and rs47958 SNPs did not alter the response to MDMA.

Conclusions

Genetic polymorphisms of the SLC6A2 gene weakly moderated the acute cardiovascular response to MDMA in controlled studies and may play a minor role in adverse cardiovascular events when MDMA is used recreationally.

Electronic supplementary material

The online version of this article (10.1007/s00228-017-2392-2) contains supplementary material, which is available to authorized users.

Acute Effects of Methylphenidate, Modafinil, and MDMA on Negative Emotion Processing

BACKGROUND

Stimulants such as methylphenidate and modafinil are frequently used as cognitive enhancers in healthy people, whereas 3,4-methylenedioxymethamphetamine (ecstasy) is proposed to enhance mood and empathy in healthy subjects. However, comparative data on the effects of methylphenidate and modafinil on negative emotions in healthy subjects have been partially missing. The aim of this study was to compare the acute effects of methylphenidate and modafinil on the neural correlates of fearful face processing using 3,4-methylenedioxymethamphetamine as a positive control.

METHODS

Using a double-blind, within-subject, placebo-controlled, cross-over design, 60 mg methylphenidate, 600 mg modafinil, and 125 mg 3,4-methylenedioxymethamphetamine were administrated to 22 healthy subjects while performing an event-related fMRI task to assess brain activation in response to fearful faces. Negative mood states were assessed with the State-Trait Anxiety Inventory and subjective ratings.

RESULTS

Relative to placebo, modafinil, but not methylphenidate or 3,4-methylenedioxymethamphetamine, increased brain activation within a limbic-cortical-striatal-pallidal-thalamic circuit during fearful face processing. Modafinil but not methylphenidate also increased amygdala responses to fearful faces compared with 3,4-methylenedioxymethamphetamine. Furthermore, activation in the middle and inferior frontal gyrus in response to fearful faces correlated positively with subjective feelings of fearfulness and depressiveness after modafinil administration.

CONCLUSIONS

Despite the cognitive enhancement effects of 600 mg modafinil in healthy people, potential adverse effects on emotion processing should be considered.

MDMA does not alter responses to the Trier Social Stress Test in humans

RATIONALE

±3,4-Methylenedioxymethamphetamine (MDMA, "ecstasy") is a stimulant-psychedelic drug with unique social effects. It may dampen reactivity to negative social stimuli such as social threat and rejection. Perhaps because of these effects, MDMA has shown promise as a treatment for post-traumatic stress disorder (PTSD). However, the effect of single doses of MDMA on responses to an acute psychosocial stressor has not been tested.

OBJECTIVES

In this study, we sought to test the effects of MDMA on responses to stress in healthy adults using a public speaking task. We hypothesized that the drug would reduce responses to the stressful task.

METHODS

Volunteers (N = 39) were randomly assigned to receive placebo (N = 13), 0.5 mg/kg MDMA (N = 13), or 1.0 mg/kg MDMA (N = 13) during a stress and a no-stress session. Dependent measures included subjective reports of drug effects and emotional responses to the task, as well as salivary cortisol, heart rate, and blood pressure.

RESULTS

The stress task produced its expected increase in physiological responses (cortisol, heart rate) and subjective ratings of stress in all three groups, and MDMA produced its expected subjective and physiological effects. MDMA alone increased ratings of subjective stress, heart rate, and saliva cortisol concentrations, but contrary to our hypothesis, it did not moderate responses to the Trier Social Stress Test.

CONCLUSIONS

Despite its efficacy in PTSD and anxiety, MDMA did not reduce either the subjective or objective responses to stress in this controlled study. The conditions under which MDMA relieves responses to negative events or memories remain to be determined.

Safety pharmacology of acute MDMA administration in healthy subjects

3,4-Methylenedioxymethamphetamine (MDMA; ecstasy) is being investigated in MDMA-assisted psychotherapy. The present study characterized the safety pharmacology of single-dose administrations of MDMA (75 or 125 mg) using data from nine double-blind, placebo-controlled, crossover studies performed in the same laboratory in a total of 166 healthy subjects. The duration of the subjective effects was 4.2 ± 1.3 h (range: 1.4-8.2 h). The 125 mg dose of MDMA produced greater 'good drug effect' ratings than 75 mg. MDMA produced moderate and transient 'bad drug effect' ratings, which were greater in women than in men. MDMA increased systolic blood pressure to >160 mmHg, heart rate >100 beats/min, and body temperature >38°C in 33%, 29% and 19% of the subjects, respectively. These proportions of subjects with hypertension (>160 mmHg), tachycardia, and body temperature >38°C were all significantly greater after 125 mg MDMA compared with the 75 mg dose. Acute and subacute adverse effects of MDMA as assessed by the List of Complaints were dose-dependent and more frequent in females. MDMA did not affect liver or kidney function at EOS 29 ± 22 days after use. No serious adverse events occurred. In conclusion, MDMA produced predominantly acute positive subjective drug effects. Bad subjective drug effects and other adverse effects were significantly more common in women. MDMA administration was overall safe in physically and psychiatrically healthy subjects and in a medical setting. However, the risks of MDMA are likely higher in patients with cardiovascular disease and remain to be investigated in patients with psychiatric disorders.

The effects of MDMA on socio-emotional processing: Does MDMA differ from other stimulants?

±3,4-Methylenedioxymethamphetamine (MDMA) is a popular recreational drug that enhances sociability and feelings of closeness with others. These "prosocial" effects appear to motivate the recreational use of MDMA and may also form the basis of its potential as an adjunct to psychotherapy. However, the extent to which MDMA differs from prototypic stimulant drugs, such as dextroamphetamine, methamphetamine, and methylphenidate, in either its behavioral effects or mechanisms of action, is not fully known. The purpose of this review is to evaluate human laboratory findings of the social effects of MDMA compared to other stimulants, ranging from simple subjective ratings of sociability to more complex elements of social processing and behavior. We also review the neurochemical mechanisms by which these drugs may impact sociability. Together, the findings reviewed here lay the groundwork for better understanding the socially enhancing effects of MDMA that distinguish it from other stimulant drugs, especially as these effects relate to the reinforcing and potentially therapeutic effects of the drug.

LSD Acutely Impairs Fear Recognition and Enhances Emotional Empathy and Sociality

Lysergic acid diethylamide (LSD) is used recreationally and has been evaluated as an adjunct to psychotherapy to treat anxiety in patients with life-threatening illness. LSD is well-known to induce perceptual alterations, but unknown is whether LSD alters emotional processing in ways that can support psychotherapy. We investigated the acute effects of LSD on emotional processing using the Face Emotion Recognition Task (FERT) and Multifaceted Empathy Test (MET). The effects of LSD on social behavior were tested using the Social Value Orientation (SVO) test. Two similar placebo-controlled, double-blind, random-order, crossover studies were conducted using 100 μg LSD in 24 subjects and 200 μg LSD in 16 subjects. All of the subjects were healthy and mostly hallucinogen-naive 25- to 65-year-old volunteers (20 men, 20 women). LSD produced feelings of happiness, trust, closeness to others, enhanced explicit and implicit emotional empathy on the MET, and impaired the recognition of sad and fearful faces on the FERT. LSD enhanced the participants' desire to be with other people and increased their prosocial behavior on the SVO test. These effects of LSD on emotion processing and sociality may be useful for LSD-assisted psychotherapy.

Clinical applications of hallucinogens: A review

Hallucinogens fall into several different classes, as broadly defined by pharmacological mechanism of action, and chemical structure. These include psychedelics, entactogens, dissociatives, and other atypical hallucinogens. Although these classes do not share a common primary mechanism of action, they do exhibit important similarities in their ability to occasion temporary but profound alterations of consciousness, involving acute changes in somatic, perceptual, cognitive, and affective processes. Such effects likely contribute to their recreational use. However, a growing body of evidence indicates that these drugs may have therapeutic applications beyond their potential for abuse. This review will present data on several classes of hallucinogens with a particular focus on psychedelics, entactogens, and dissociatives, for which clinical utility has been most extensively documented. Information on each class is presented in turn, tracing relevant historical insights, highlighting similarities and differences between the classes from the molecular to the behavioral level, and presenting the most up-to-date information on clinically oriented research with these substances, with important ramifications for their potential therapeutic value. (PsycINFO Database Record

Effects of 3,4-methylenedioxymethamphetamine on socioemotional feelings, authenticity, and autobiographical disclosure in healthy volunteers in a controlled setting

The drug 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy", "molly") is a widely used illicit drug and experimental adjunct to psychotherapy. MDMA has unusual, poorly understood socioemotional effects, including feelings of interpersonal closeness and sociability. To better understand these effects, we conducted a small (n=12) within-subjects double-blind placebo controlled study of the effects of 1.5 mg/kg oral MDMA on social emotions and autobiographical disclosure in a controlled setting. MDMA displayed both sedative- and stimulant-like effects, including increased self-report anxiety. At the same time, MDMA positively altered evaluation of the self (i.e. increasing feelings of authenticity) while decreasing concerns about negative evaluation by others (i.e. decreasing social anxiety). Consistent with these feelings, MDMA increased how comfortable participants felt describing emotional memories. Overall, MDMA produced a prosocial syndrome that seemed to facilitate emotional disclosure and that appears consistent with the suggestion that it represents a novel pharmacological class.

Naltrexone alters the processing of social and emotional stimuli in healthy adults

Endogenous opioids have complex social effects that may depend on specific receptor actions and vary depending on the "stage" of social behavior (e.g., seeking vs. responding to social stimuli). We tested the effects of a nonspecific opioid antagonist, naltrexone (NTX), on social processing in humans. NTX is used to treat alcohol and opiate dependence, and may affect both mu and kappa-opioid systems. We assessed attention ("seeking"), and subjective and psychophysiological responses ("responding") to positive and negative social stimuli. Based on literature suggesting mu-opioid blockade impairs positive social responses, we hypothesized that NTX would decrease responses to positive social stimuli. We also tested responses to negative stimuli, which might be either increased by NTX's mu-opioid effects or decreased by its kappa-opioid effects. Thirty-four healthy volunteers received placebo, 25 mg, or 50 mg NTX across three sessions under double-blind conditions. At each session, participants completed measures of attention, identification, and emotional responses for emotional faces and scenes. NTX increased attention to emotional expressions, slowed identification of sadness and fear, and decreased ratings of arousal for social and nonsocial emotional scenes. These findings are more consistent with anxiolytic kappa-antagonist than mu-blocking effects, suggesting effects on kappa receptors may contribute to the clinical effects of NTX.

Effects of buprenorphine on responses to social stimuli in healthy adults

In addition to its classical role in mediating responses to pain, the opioid system is strongly implicated in the regulation of social behavior. In young laboratory animals, low doses of opioid analgesic drugs reduce responses to isolation distress and increase play behavior. However, little is known about how opioid drugs affect responses to social stimuli in humans. Here we examined the effects of buprenorphine, a mu-opioid partial agonist and kappa-antagonist, on three dimensions of social processing: (i) responses to simulated social rejection, (ii) attention to emotional facial expressions, and (iii) emotional responses to images with and without social content. Healthy adults (N=36) attended two sessions during which they received either placebo or 0.2mg sublingual buprenorphine in randomized order, under double-blind conditions. Ninety minutes after drug administration, they completed three behavioral tasks: (i) a virtual ball-toss game in which they were first included and then excluded by the other players; (ii) an attention task in which they were shown pairs of faces (one emotional and one neutral), while the direction of their gazes was recorded using electrooculography, and (iii) a picture-viewing task, in which they rated standardized images with and without social content. During the ball-toss game, buprenorphine decreased perceived social rejection. During the attention task, the drug reduced initial attention to fearful facial expressions, without influencing attention to angry, happy, or sad faces. Finally, during the picture-viewing task, buprenorphine increased ratings of positivity of images with social content without affecting ratings of nonsocial images. These results suggest that even at low doses, opioid analgesic drugs reduce responses to some types of negative social stimuli while enhancing positive responses to social stimuli. This provides further support for the role of the opioid system in mediating responses to social rejection and social reward.

The prosocial effects of 3,4-methylenedioxymethamphetamine (MDMA): Controlled studies in humans and laboratory animals

Users of ±3,4-methylenedioxymethamphetamine (MDMA; 'ecstasy') report prosocial effects such as sociability and empathy. Supporting these apparently unique social effects, data from controlled laboratory studies indicate that MDMA alters social feelings, information processing, and behavior in humans, and social behavior in rodents. Here, we review this growing body of evidence. In rodents, MDMA increases passive prosocial behavior (adjacent lying) and social reward while decreasing aggression, effects that may involve serotonin 1A receptor mediated oxytocin release interacting with vasopressin receptor 1A. In humans, MDMA increases plasma oxytocin and produces feelings of social affiliation. It decreases identification of negative facial expressions (cognitive empathy) and blunts responses to social rejection, while enhancing responses to others' positive emotions (emotional empathy) and increasing social approach. Thus, consistent with drug folklore, laboratory administration of MDMA robustly alters social processing in humans and increases social approach in humans and animals. Effects are consistent with increased sociability, with mixed evidence about enhanced empathy. These neurobiologically-complex prosocial effects likely motivate recreational ecstasy use.

Oxytocin and MDMA ('Ecstasy') enhance social reward in rats

RATIONALE

Oxytocin (OT), vasopressin (AVP) and 3,4 methylenedioxymethamphetamine (MDMA, 'Ecstasy') all increase social interaction in rats, perhaps by enhancing the rewarding value of social encounters.

OBJECTIVES

Here, we used the conditioned place preference (CPP) paradigm to assess the intrinsic rewarding effects of OT, AVP and MDMA, and whether these effects are enhanced by the presence of a conspecific, or a dynamic, tactile object (a tennis ball).

METHODS

Adult male rats received conditioning sessions in a CPP apparatus twice a day (vehicle at 10 a.m., drug at 3 p.m.). Experiment 1 involved conditioning with OT (0.5 mg/kg, intraperitoneal (i.p.)), AVP (0.005 mg/kg, i.p.) or MDMA (5 mg/kg, i.p.). Experiments 2 and 3 involved conditioning with the same treatments but in the presence of a conspecific receiving the same treatment (social-CPP) or in the presence of a tennis ball (object-CPP), respectively. Conditioned place preference was assessed 24 h, 2 weeks and 4 weeks later.

RESULTS

OT, AVP and MDMA did not produce a conventional CPP. However, when the conditioning environment also contained a conspecific both OT and MDMA induced a significant CPP lasting for at least 4 weeks. Rats given OT and MDMA also developed a more modest yet significant CPP for the environment where they encountered a tennis ball.

CONCLUSIONS

These results indicate that OT and MDMA can augment the rewarding effects of social interaction, but also interaction with a dynamic and tactile non-social object. AVP does not condition social- or object-CPPs and may promote social proximity by inducing generalized anxiety and defensive aggregation.