Simultaneous polysubstance use among Danish 3,4-methylenedioxymethamphetamine and hallucinogen users: combination patterns and proposed biological bases

Simultaneous cannabis and psychedelic use among festival and concert attendees in Colorado: characterizing enhancement and adverse reactions using mixed methods

BACKGROUND

Most studies examining the simultaneous use of cannabis with other drugs have focused on cannabis and alcohol, with fewer studies examining simultaneous use of cannabis with other drugs. The United States is currently experiencing an upward trend in psychedelic use and there is an increasing need to characterize cannabis and psychedelic drug interactions to best inform public health recommendations.

MATERIALS AND METHODS

A mixed methods field study design was used to survey participants (N = 128) on their lifetime co-use of cannabis with other drugs. Participants who reported lifetime co-use of cannabis and psychedelics (N = 63) were then asked open-ended questions about their most recent simultaneous co-use experience (i.e., how cannabis enhanced their psychedelic experience and whether they experienced any adverse reactions). We conducted a thematic analysis of responses describing how cannabis enhanced the psychedelic experience (N = 54). However, due to low response rate for participants reporting an adverse reaction (N = 7, 11.1%), responses to this question were not analyzed thematically and are instead presented individually.

RESULTS

Themes included tension reduction and balancing of drug effects (N = 27, 50%), enhancement to psychological processes (N = 11, 20.4%), intensified psychedelic drug effects (N = 12, 22.2%), enhanced psychedelic come-down experience (N = 8, 14.8%), and overall ambiguous enhancement (N = 7, 13%). Among participants reporting an adverse reaction, individual responses included increased anxiety and intensity of the experience, decreased sociability, increased negative affect, sleepiness, disassociation, and confusion.

CONCLUSION

Additional research is warranted to better characterize cannabis and psychedelic drug interactions to best inform public health recommendations.

Epigenetic drugs and psychedelics as emerging therapies for alcohol use disorder: insights from preclinical studies

Alcohol use disorder (AUD) is a public health issue that affects millions of people worldwide leading to physical, mental and socio-economic consequences. While current treatments for AUD have provided relief to individuals, their effectiveness on the long term is often limited, leaving a number of affected individuals without sustainable solutions. In this review, we aim to explore two emerging approaches for AUD: psychedelics and epigenetic drugs (i.e., epidrugs). By examining preclinical studies, different animal species and procedures, we delve into the potential benefits of each of these treatments in terms of addictive behaviors (alcohol drinking and seeking, motivation to drink alcohol and prevention of relapse). Because psychedelics and epidrugs may share common and complementary mechanisms of action, there is an exciting opportunity for exploring synergies between these approaches and their parallel effectiveness in treating AUD and the diverse associated psychiatric conditions.

Acute effects of MDMA and LSD co-administration in a double-blind placebo-controlled study in healthy participants

There is renewed interest in the use of lysergic acid diethylamide (LSD) in psychiatric research and practice. Although acute subjective effects of LSD are mostly positive, negative subjective effects, including anxiety, may occur. The induction of overall positive acute subjective effects is desired in psychedelic-assisted therapy because positive acute experiences are associated with greater therapeutic long-term benefits. 3,4-Methylenedioxymethamphetamine (MDMA) produces marked positive subjective effects and is used recreationally with LSD, known as "candyflipping." The present study investigated whether the co-administration of MDMA can be used to augment acute subjective effects of LSD. We used a double-blind, randomized, placebo-controlled, crossover design with 24 healthy subjects (12 women, 12 men) to compare the co-administration of MDMA (100 mg) and LSD (100 µg) with MDMA and LSD administration alone and placebo. Outcome measures included subjective, autonomic, and endocrine effects and pharmacokinetics. MDMA co-administration with LSD did not change the quality of acute subjective effects compared with LSD alone. However, acute subjective effects lasted longer after LSD + MDMA co-administration compared with LSD and MDMA alone, consistent with higher plasma concentrations of LSD (Cmax and area under the curve) and a longer plasma elimination half-life of LSD when MDMA was co-administered. The LSD + MDMA combination increased blood pressure, heart rate, and pupil size more than LSD alone. Both MDMA alone and the LSD + MDMA combination increased oxytocin levels more than LSD alone. Overall, the co-administration of MDMA (100 mg) did not improve acute effects or the safety profile of LSD (100 µg). The combined use of MDMA and LSD is unlikely to provide relevant benefits over LSD alone in psychedelic-assisted therapy. Trial registration: ClinicalTrials.gov identifier: NCT04516902.

Co-use of MDMA with psilocybin/LSD may buffer against challenging experiences and enhance positive experiences

Psilocybin and lysergic acid diethylamide (LSD) experiences can range from very positive to highly challenging (e.g., fear, grief, and paranoia). These challenging experiences contribute to hesitancy toward psychedelic-assisted psychotherapy among health care providers and patients. Co-use of 3,4-Methylenedioxy methamphetamine (MDMA) with psilocybin/LSD anecdotally reduces challenging experiences and enhances positive experiences associated with psilocybin/LSD. However, limited research has investigated the acute effects of co-use of MDMA and psilocybin/LSD. In a prospective convenience sample (N = 698) of individuals with plans to use psilocybin/LSD, we examined whether co-use of MDMA with psilocybin/LSD (n = 27) is associated with differences in challenging or positive experiences. Challenging experiences were measured using the Challenging Experiences Questionnaire and positive experiences were measured using the Mystical Experience Questionnaire and single-item measures of self-compassion, compassion, love, and gratitude. Potentially confounding variables were identified and included as covariates. Relative to psilocybin/LSD alone, co-use of psilocybin/LSD with a self-reported low (but not medium-high) dose of MDMA was associated with significantly less intense total challenging experiences, grief, and fear, as well as increased self-compassion, love and gratitude. Co-use of psilocybin/LSD and MDMA was not associated with differences in mystical-type experiences or compassion. Findings suggest co-use of MDMA with psilocybin/LSD may buffer against some aspects of challenging experiences and enhance certain positive experiences. Limitations include use of a convenience sample, small sample size, and non-experimental design. Additional studies (including controlled dose-response studies) that examine the effects and safety of co-administering MDMA with psilocybin/LSD (in healthy controls and clinical samples) are warranted and may assist the development of personalized treatments.

Prevalence of psilocybin use in vaping and associated factors: a study among amphetamine-type stimulants (ATS) use disorder in Malaysia

BACKGROUND

The emergence of New Psychoactive Substances (NPS), including synthetic psilocybin, has raised concern among health experts due to the numerous health and socioeconomic consequences. The current trend is shifting to the hazardous use of synthetic psilocybin in vaping, and little is known about the prevalence of use, specifically among amphetamine-type stimulants (ATS) users.

METHODS

Interviewer-administered questionnaires were conducted in drug detention centers between March and October 2022. The study was conducted using ASSIST 3.0 and obtained information on the respondents' socio-demographic characteristics and clinical profiles. N = 355 ATS users were enrolled in this study.

RESULTS

The results show a high prevalence of psilocybin vaping among ATS users (182/355, 53.1%). Most of the respondents were males (85.1%) and unmarried (69.3%), with a mean age of 29.2 (SD = 7.3). Across all respondents, five factors were associated with psilocybin vaping: tobacco smoking, aOR =5.790 (95% CI: 1.723, 8.183); cannabis uses, aOR= 9.152 (95% CI: 2.693, 10.396); and alcohol use, aOR= 3.137 (95% CI: 1.461, 5.817). Respondents of the Malay race had higher odds of being involved in psilocybin vaping compared to other races, with aOR= 1.638 (0.043, 2.459). Meanwhile, a reduction in age by 1.9 will increase the likelihood of involvement in psilocybin vaping with aOR = 1.897 (95% CI: 0.857, 1.938).

CONCLUSION

Psilocybin in vaping is growing among ATS users and across all populations. Unfortunately, knowledge regarding the long-term effects on health is limited. Further studies should highlight the harmful effects of psilocybin and the potential risk of psilocybin vaping among the younger population.

Polysubstance use in South Asia

PURPOSE OF REVIEW

Polysubstance use is very common in the world, but there has been limited research in this area. South Asia is sandwiched between two of the world's largest heroin producing areas: the Golden Crescent and the Golden Triangle. The burden and prevalence of polysubstance use have not been estimated in this region of the world. We review the research findings on polysubstance use in different South Asian countries. The review also comments on the gaps in knowledge regarding polysubstance use in this region of the world.

RECENT FINDINGS

The available literature on polysubstance use from South Asia suggests its widespread presence in the region, ranging from 20 to 90%, more commonly among illicit opioid drug users and injection drug users. Most of the available data is from epidemiological studies. There are few studies on the adverse effects of polysubstance use, but the limited data clearly suggests an elevated risk of comorbid psychopathology and health problems.

SUMMARY

Polysubstance use still lacks a consensus definition. There is a need of more research on its prevalence, effects on health, and prevention and treatment.

Patterns of polysubstance use and clinical comorbidity among persons seeking substance use treatment: An observational study

INTRODUCTION

Polysubstance use is common among individuals seeking treatment for substance use disorders (SUD). However, we know less about patterns and correlates of polysubstance use among treatment-seeking populations. The current study aimed to identify latent patterns of polysubstance use and associated risk factors in persons entering SUD treatment.

METHODS

Patients (N = 28,526) being admitted for substance use treatment reported on their use of thirteen substances (e.g., alcohol, cannabis, cocaine, amphetamines, methamphetamines, other stimulants, heroin, other opioids, benzodiazepines, inhalants, synthetics, hallucinogens, and club drugs) in the month before treatment and prior to the month before treatment. Latent class analysis (LCA) determined the relationship between class membership and gender, age, employment status, unstable housing, self-harm, overdose, past treatment, depression, generalized anxiety disorder, and/or post-traumatic stress disorder (PTSD).

RESULTS

Identified classes included: 1) Alcohol primary, 2) Moderate probability of past-month alcohol, cannabis, and/or opioid use; 3) Alcohol primary, Lifetime cannabis and cocaine use; 4) Opioid primary, Lifetime use of alcohol, cannabis, hallucinogens, club drugs, amphetamines, and cocaine; 5) Moderate probability of past-month alcohol, cannabis, and/or opioid use, Lifetime use of various substances; 6) Alcohol and cannabis primary, Lifetime use of various substances; and 7) High past-month polysubstance use. Individuals who engaged in past-month polysubstance use attended to face elevated risk of screening positive for recent unstable housing, unemployment, depression, anxiety, PTSD, self-harm, and overdose.

CONCLUSIONS

Current polysubstance use is associated with significant clinical complexity. Tailored treatments that reduce harms resulting from polysubstance use and related psychiatric comorbidity may improve treatment outcomes in this population.

Classic psychedelics and alcohol use disorders: A systematic review of human and animal studies

Classic psychedelics refer to substances such as lysergic acid diethylamide (LSD), psilocybin, ayahuasca, and mescaline, which induce altered states of consciousness by acting mainly on 5-HT_2A receptors. Recently, the interest of psychedelics as pharmacological treatment for psychiatric disorders has increased significantly, including their use on problematic use of alcohol. This systematic review is aimed to analyse the last two decades of studies examining the relationship between classic psychedelics and alcohol consumption. We searched PubMed and PsycInfo for human and preclinical studies published between January 2000 to December 2021. The search identified 639 publications. After selection, 27 studies were included. Human studies (n = 20) generally show promising data and seem to indicate that classic psychedelics could help reduce alcohol consumption. Nevertheless, some of these studies present methodological concerns such as low number of participants, lack of control group or difficulty in determining the effect of classic psychedelics in isolation. On the other hand, preclinical studies (n = 7) investigating the effect of these compounds on voluntary alcohol consumption are scarce and show some conflicting data. Among these compounds, psilocybin seems to show the most consistent data indicating that this compound could be a potential candidate to treat alcohol use disorders. In the absence of understanding the biological and/or psychological mechanisms, more studies including methodological quality parameters are needed to finally determine the effects of classic psychedelics on alcohol consumption.

The use of classic psychedelics among adults: a Danish online survey study

BACKGROUND

Clinical studies report preliminary therapeutic effects of classic psychedelic drugs in several psychiatric conditions and international drug trends show increased use of these compounds. However, the epidemiology of classic psychedelic drug use in Scandinavian countries remains sparsely investigated. To this end, we investigated the patterns of use and the subjectively perceived acute and persisting effects of lysergic acid diethylamide (LSD), psilocybin, N,N-dimethyltryptamine (DMT), and mescaline, among Danish adults.

METHODS

An anonymous online survey with 152 items was conducted using the secure survey web application REDCap. Results were presented descriptively and as comparisons between psychedelic drugs.

RESULTS

Five-hundred participants (30.0% female, mean age 34.5 years) were included. Classic psychedelics were mostly used with therapeutic (28.0%) or spiritual (27.2%) intentions. Sixty-seven per cent used classic psychedelics once a year or less. Most participants (56.4%) preferred using psilocybin. Classic psychedelic use was for some individuals, associated with hazardous use of alcohol (39.4%). Among participants with a psychiatric treatment history, 80.9% reported subjective improvements in symptoms following classic psychedelic use. Participants' most memorable experiences were moderate-to-strong mystical-type experiences (MEQ30 mean ± SD 3.4 ± 1.0; range 1-5) and had positive persisting effects on well-being (mean ± SD 2.1 ± 1.0), social relationships (mean ± SD 1.7 ± 1.2), meaning of life (mean ± SD 1.9 ± 1.1), and mood (mean ± SD 1.8 ± 1.1); range -3 to 3. DMT users experienced significantly greater subjective positive effects.

CONCLUSIONS

Classic psychedelics were mostly used therapeutically or spiritually and had self-reported positive persisting effects, but were also associated with hazardous use of alcohol, among Danish adults. DMT was associated with significantly greater positive effects compared to LSD and psilocybin.

Adverse experiences resulting in emergency medical treatment seeking following the use of magic mushrooms

BACKGROUND

Psilocybin-containing mushrooms are used for recreational, spiritual, self-development and therapeutic purposes. However, physiologically relatively nontoxic, adverse reactions are occasionally reported.

AIMS

This study investigated the 12-month prevalence and nature of magic mushroom-related adverse reactions resulting in emergency medical treatment seeking in a global sample of people reporting magic mushroom use.

METHODS

We use data from the 2017 Global Drug Survey - a large anonymous online survey on patterns of drug use conducted between November 2016 and January 2017.

RESULTS

Out of 9233 past year magic mushroom users, 19 (0.2%) reported having sought emergency medical treatment, with a per-event risk estimate of 0.06%. Young age was the only predictor associated with higher risk of emergency medical presentations. The most common symptoms were psychological, namely anxiety/panic and paranoia/suspiciousness. Poor 'mindset', poor 'setting' and mixing substances were most reported reasons for incidents. All but one respondent returned back to normality within 24 h.

CONCLUSIONS

The results confirm psilocybin mushrooms are a relatively safe drug, with serious incidents rare and short lasting. Providing harm-reduction information likely plays a key role in preventing adverse effects. More research is needed to examine the detailed circumstances and predictors of adverse reactions including rarer physiological reactions.

Polysubstance Use in Early Adulthood: Patterns and Developmental Precursors in an Urban Cohort

Polysubstance use (i.e., simultaneous or sequential use of different psychoactive substances) is associated with increases in the risk of severe health problems and social impairments. The present study leverages community-representative, long-term longitudinal data from an urban cohort to assess: (a) the prevalence and continuation of polysubstance use between adolescence and early adulthood; (b) different patterns of polysubstance use (i.e., combinations of substances) in early adulthood; and (c) childhood risk factors for polysubstance use in early adulthood. At age 20 (n = 1,180), respondents provided comprehensive self-reported information on past-year substance use, including use of legal and illicit substances (e.g., cannabinoids, stimulants, and hallucinogens), and nonmedical use of prescription drugs (e.g., opioids, tranquilizers). In adolescence (ages 13–17), limited versions of this questionnaire were administered. In childhood (ages 7–11), potential risk factors, including individual-level factors (e.g., sensation-seeking, low self-control, aggression, and internalizing symptoms) and social-environmental factors (e.g., social stressors, exposure to others’ substance use), were assessed. We fitted latent class models to identify classes of participants with different substance use profiles in early adulthood. The results show that polysubstance use increased between early adolescence and early adulthood. The continuation of polysubstance use was common (stability between all adjacent assessments: odds ratio >7). At age 20, more than one-third of participants reported polysubstance use (involving illicit substances, nonmedical use of prescription drugs, and cannabidiol). Four latent classes with polysubstance use were identified: (1) broad spectrum of substances; (2) cannabis and club drugs; (3) cannabis and the nonmedical use of prescription drugs; and (4) different cannabinoids. Risk factors for any polysubstance use included childhood sensation-seeking and exposure to others’ substance use; some childhood risk factors were differentially associated with the four classes (e.g., low self-control in childhood was associated with an increased likelihood of being in the broad spectrum class). The classes also differed with regard to socio-demographic factors. This study revealed that polysubstance use is a widespread and multifaceted phenomenon that typically emerges during adolescence. To facilitate the design of tailored prevention mechanisms, the heterogeneity of polysubstance use and respective socio-demographic and developmental precursors need to be considered.

Psychedelic experience dose-dependently modulated by cannabis: results of a prospective online survey

RATIONALE

Classic psychedelics are currently being studied as novel treatments for a range of psychiatric disorders. However, research on how psychedelics interact with other psychoactive substances remains scarce.

OBJECTIVES

The current study aimed to explore the subjective effects of psychedelics when used alongside cannabis.

METHODS

Participants (n = 321) completed a set of online surveys at 2 time points: 7 days before, and 1 day after a planned experience with a serotonergic psychedelic. The collected data included demographics, environmental factors (so-called setting) and five validated questionnaires: Mystical Experience Questionnaire (MEQ), visual subscales of Altered States of Consciousness Questionnaire (ASC-Vis), Challenging Experience Questionnaire (CEQ), Ego Dissolution Inventory (EDI) and Emotional Breakthrough Inventory (EBI). Participants were grouped according to whether they had reported using no cannabis (n = 195) or low (n = 53), medium (n = 45) or high (n = 28) dose, directly concomitant with the psychedelic. Multivariate analysis of covariance (MANCOVA) and contrasts was used to analyse differences in subjective effects between groups while controlling for potential confounding contextual 'setting' variables.

RESULTS

The simultaneous use of cannabis together with classic serotonergic psychedelics was associated with more intense psychedelic experience across a range of measures: a linear relationship was found between dose and MEQ, ASC-Vis and EDI scores, while a quadratic relationship was found for CEQ scores. No relationship was found between the dose of cannabis and the EBI.

CONCLUSIONS

Results imply a possible interaction between the cannabis and psychedelic on acute subjective experiences; however, design limitations hamper our ability to draw firm inferences on directions of causality and the clinical implications of any such interactions.

Trends in LSD use among US adults: 2015-2018

BACKGROUND

The recent use of LSD to treat severe psychological disorders in several clinical applications has proven effective in reducing symptoms and distressing events. Trend analyses are warranted to provide the most current data for clinical and health interventions. The purpose of this study was to examine trends in LSD use among adults in the United States.

METHODS

A secondary analysis of the 2015-2018 National Survey on Drug Use and Health was conducted on 168, 562 adults ages 18 and older.

RESULTS

Past-year LSD use increased 56.4% (P < .0001) from 2015 to 2018. The proportion of LSD users ages 26-34 increased from 19.6% to 31.1% (P < .0001), ages 35-49 increased from 2.73% to 8.82% (P < .0001) and 50 years or older increased from 1.83% to 2.66% (P < .0001). LSD use among bisexual individuals increased from 11.2% to 13.0% (P < .0001). LSD use among individuals with a college degree or more increased from 18.2% to 31.1% (P < .0001). Significant decreases in LSD use were present in individuals who were multi-racial (P < .0001), less than high school education P < .0001), high school education (P < .001), and perceived great risk of drugs (P < .0001).

CONCLUSIONS

LSD use in the US jumped 56.4% from 2015 to 2018. Results from the present study can inform prevention and harm reduction efforts (e.g., co-morbid substance use interventions, health messaging).

Recreational use of psychedelics is associated with elevated personality trait openness: Exploration of associations with brain serotonin markers

BACKGROUND

Recent studies have suggested therapeutic benefits of psychedelics for a variety of mental health conditions. The understanding of how single psychedelic administrations can induce long-lasting effects are, in large, still lacking. However, recent studies in both healthy and clinical populations suggest a role for personality changes.

AIM

To test support for some of these plausible mechanisms we evaluated (cross-sectional) associations between recreational use of psychedelics and 3,4-methylene-dioxymethamphetamine (MDMA) and (a) personality measures and (b) key markers of cerebral serotonergic signalling (serotonin transporter and serotonin-2A-receptor binding).

METHODS

In 10 psychedelic-preferring recreational users, 14 MDMA-preferring users and 21 non-using controls, personality was assessed using the 'big five' instrument Revised NEO Personality Inventory (NEO-PI-R). Frontal serotonin transporter and serotonin-2A-receptor binding potentials were quantified using [¹¹C]DASB and [¹⁸F]altanserin positron emission tomography, respectively.

RESULTS

Of the five NEO-PI-R traits, only openness to experience scores differed between the three groups; psychedelic-preferring recreational users showing higher openness to experience scores when compared with both MDMA-preferring users and controls. Openness to experience scores were positively associated with lifetime number of psychedelic exposures, and among all MDMA-preferring user/psychedelic-preferring recreational user individuals, frontal serotonin transporter binding - but not frontal serotonin-2A-receptor binding - was positively associated with openness to experience.

CONCLUSION

Our findings from this cross-sectional study support increasing evidence of a positive association between psychedelic experiences and openness to experience, and (a) expands this to the context of 'recreational' psychedelics use, and (b) links serotonergic neurotransmission to openness to experience. A modulation of personality induced by psychedelic experiences may have important therapeutic implications via its impact on peoples' value systems, cognitive flexibility, and individual and social behaviour.

Physical and psychosocial factors associated with psychostimulant use in a nationally representative sample of French adolescents: Specificities of cocaine, amphetamine, and ecstasy use

PURPOSE

Patterns of psychostimulant (PST) use, psychological and physical factors, and family relationships were investigated in a nationally representative sample of adolescents. The differences between users of cocaine (Cc), ecstasy/MDMA, and amphetamine (EA) were analyzed, taking into account gender differences.

METHODS

Substance use, psychological factors (lifetime suicide attempts, suicidal thoughts in the previous year, visits to a mental health professional), physical factors (health and body shape perceptions (BSP), body mass index (BMI)), and family relationships (existence of disagreements with parents, relationships with mother and father) were investigated in 26,351 17-year-old French adolescents.

RESULTS

Lifetime suicidal behavior was strongly associated with EA use only. Suicidal ideation in the previous year was associated with Cc use among both boys and girls and associated with EA use among girls. Compared to Cc users, more EA users were overweight, while more Cc users were underweight compared to EA users. BSP, BMI, and EA use were related in girls only. Having a good or very good relationship with both mother and father was negatively associated with Cc use in boys and girls. Girls who had a good or very good relationship with their fathers seemed to be less prone to use EA. Boys with a good or very good relationship with their mothers seemed to be less prone to use EA.

CONCLUSION

The results of the present study could serve as a basis for prevention and harm reduction strategies/programs targeting youth use and for the adaptation of these strategies/programs according to substance and gender.

The importance of considering polysubstance use: lessons from cocaine research

BACKGROUND

Polysubstance use (PSU) is prevalent among individuals with substance use disorders, but the vast majority of preclinical substance use research has focused on individual substances in isolation. Cocaine has been prevalent in the repertoire of persons who use more than one illicit substance.

METHODS

We conducted a meta-analysis combining results from literature searches and secondary data analyses to estimate the prevalence of simultaneous and concurrent cocaine + alcohol and cocaine + cannabis use among cocaine users. We next summarized the small body of literature on behavioral, cognitive and neurobiological consequences of cocaine PSU across species, with a focus on alcohol and cannabis. Finally, we used systematic literature searches to assess the extent to which human and animal studies on the neurobiological consequences of cocaine include PSU subjects.

RESULTS

The estimated prevalence of simultaneous and concurrent alcohol use among human cocaine users was 74% and 77%, respectively. The estimated prevalence of simultaneous and concurrent cannabis use among cocaine users was 38% and 64%, respectively. Consumption of alcohol or cannabis with cocaine enhances subjective responses to cocaine, concomitant with changes in cocaine metabolism that increase blood cocaine levels, and, in the case of alcohol, produce the psychoactive metabolite cocaethylene. There is also consistent evidence for neurobiological effects of cocaine + alcohol combinations. However, animal PSU research with cocaine lags behind human research.

CONCLUSION

Based on the prevalence and known consequences of PSU, consideration of PSU in both human and animal research is vital for understanding patterns of substance use.

Human pharmacology of 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) after repeated doses taken 4 h apart Human pharmacology of MDMA after repeated doses taken 4 h apart

3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) is a popular psychostimulant, frequently associated with multiple administrations over a short period of time. Repeated administration of MDMA in experimental settings induces tolerance and metabolic inhibition. The aim is to determine the acute pharmacological effects and pharmacokinetics resulting from two consecutive 100mg doses of MDMA separated by 4h. Ten male volunteers participated in a randomized, double-blind, crossover, placebo-controlled trial. The four conditions were placebo plus placebo, placebo plus MDMA, MDMA plus placebo, and MDMA plus MDMA. Outcome variables included pharmacological effects and pharmacokinetic parameters. After a second dose of MDMA, most effects were similar to those after a single dose, despite a doubling of MDMA concentrations (except for systolic blood pressure and reaction time). After repeated MDMA administration, a 2-fold increase was observed in MDMA plasma concentrations. For a simple dose accumulation MDMA and MDA concentrations were higher (+23.1% Cmax and +17.1% AUC for MDMA and +14.2% Cmax and +10.3% AUC for MDA) and HMMA and HMA concentrations lower (-43.3% Cmax and -39.9% AUC for HMMA and -33.2% Cmax and -35.1% AUC for HMA) than expected, probably related to MDMA metabolic autoinhibition. Although MDMA concentrations doubled after the second dose, most pharmacological effects were similar or slightly higher in comparison to the single administration, except for systolic blood pressure and reaction time which were greater than predicted. The pharmacokinetic-effects relationship suggests that when MDMA is administered at a 4h interval there exists a phenomenon of acute tolerance to its effects.

Polysubstance use: diagnostic challenges, patterns of use and health

PURPOSE OF REVIEW

Polysubstance use is common, particularly amongst some age groups and subcultures. It is also associated with elevated risk of psychiatric and physical health problems. We review the recent research findings, comment on changes to polysubstance diagnoses, report on contemporary clinical and epidemiological polysubstance trends, and examine the efficacy of preventive and treatment approaches.

RECENT FINDINGS

Approaches to describing polysubstance use profiles are becoming more sophisticated. Models over the last 18 months that employ latent class analysis typically report a no use or limited-range cluster (alcohol, tobacco and marijuana), a moderate-range cluster (limited range and amphetamine derivatives), and an extended-range cluster (moderate range, and nonmedical use of prescription drugs and other illicit drugs). Prevalence rates vary as a function of the population surveyed. Wide-ranging polysubstance users carry higher risk of comorbid psychopathology, health problems, and deficits in cognitive functioning.

SUMMARY

Wide-ranging polysubstance use is more prevalent in subcultures such as 'ravers' (dance club attendees) and those already dependent on substances. Health risks are elevated in these groups. Research into the prevention and treatment of polysubstance use is underdeveloped. There may be benefit in targeting specific polysubstance use and risk profiles in prevention and clinical research.