Acute effects of nocturnal doses of MDMA on measures of impulsivity and psychomotor performance throughout the night

Cognitive functioning associated with acute and subacute effects of classic psychedelics and MDMA - a systematic review and meta-analysis

Classic psychedelics and MDMA have a colorful history of recreational use, and both have recently been re-evaluated as tools for the treatment of psychiatric disorders. Several studies have been carried out to assess potential long-term effects of a regular use on cognition, delivering distinct results for psychedelics and MDMA. However, to date knowledge is scarce on cognitive performance during acute effects of those substances. In this systematic review and meta-analysis, we investigate how cognitive functioning is affected by psychedelics and MDMA during the acute drug effects and the sub-acute ("afterglow") window. Our quantitative analyses suggest that acute cognitive performance is differentially affected by psychedelics when compared to MDMA: psychedelics impair attention and executive function, whereas MDMA primarily affects memory, leaving executive functions and attention unaffected. Our qualitative analyses reveal that executive functioning and creativity may be increased during a window of at least 24 h after the acute effects of psychedelics have subsided, whereas no such results have been observed for MDMA. Our findings may contribute to inform recommendations on harm reduction for recreational settings and to help fostering differential approaches for the use of psychedelics and MDMA within a therapeutic framework.

Driving under the influence of cocaine and MDMA: Relationship between blood concentrations and results from clinical test of impairment

The general use of cocaine is increasing in recent years, while the trend for 3,4-methylenedioxymethamphetamine (MDMA) is less clear. The relationship between blood concentrations and impairment is poorly understood, which complicates interpretation. The aims of this study were to report prevalence and blood concentrations of cocaine and MDMA in drugged drivers, and to investigate the relationship between blood concentrations and impairment. Samples of whole blood were collected from apprehended drivers in the period 2000-2022, and a clinical test of impairment (CTI) was simultaneously performed. The samples were initially analyzed for cocaine and MDMA using gas chromatography-mass spectrometry (until 2009 and 2012, respectively), and later using ultra-high-performance liquid chromatography-tandem mass spectrometry. Overall, cocaine was detected in 2,331 cases and MDMA in 2,569 cases. There were 377 and 85 mono cases of cocaine and MDMA, respectively. In the mono cases, the median cocaine concentration was 0.09 mg/L (range: 0.02-1.15 mg/L), and 54% of the drivers were clinically impaired. The median MDMA concentration was 0.19 mg/L (range: 0.04-1.36 mg/L), and 38% were clinically impaired. There was a statistically significant difference in the median cocaine concentration between drivers assessed as not impaired (0.07 mg/L) and drivers assessed as impaired (0.10 mg/L) (P = 0.009). There was also a significant effect of the blood concentration of cocaine (adjusted odds ratio [aOR] = 6.42, 95% confidence interval [CI] = 1.13-36.53, P = 0.036) and driving during the evening/night-time (aOR = 2.17, 95% CI = 1.34-3.51, P = 0.002) on the probability of being assessed as impaired on the CTI. No significant differences were found for MDMA. Many drivers are not assessed as impaired on a CTI following cocaine or especially MDMA use. For cocaine, a relationship between blood concentrations and impairment was demonstrated, but this could not be shown for MDMA.

Pharmacological effects of methylone and MDMA in humans

Methylone is one of the most common synthetic cathinones popularized as a substitute for 3,4-methylenedioxymethamphetamine (MDMA, midomafetamine) owing to its similar effects among users. Both psychostimulants exhibit similar chemistry (i.e., methylone is a β-keto analog of MDMA) and mechanisms of action. Currently, the pharmacology of methylone remains scarcely explored in humans. Herein, we aimed to evaluate the acute pharmacological effects of methylone and its abuse potential in humans when compared with that of MDMA following oral administration under controlled conditions. Seventeen participants of both sexes (14 males, 3 females) with a previous history of psychostimulant use completed a randomized, double-blind, placebo-controlled, crossover clinical trial. Participants received a single oral dose of 200 mg of methylone, 100 mg of MDMA, and a placebo. The variables included physiological effects (blood pressure, heart rate, oral temperature, pupil diameter), subjective effects using visual analog scales (VAS), the short form of the Addiction Research Center Inventory (ARCI), the Evaluation of Subjective Effects of Substances with Abuse Potential questionnaire (VESSPA-SSE), and the Sensitivity to Drug Reinforcement Questionnaire (SDRQ), and psychomotor performance (Maddox wing, psychomotor vigilance task). We observed that methylone could significantly increase blood pressure and heart rate and induce pleasurable effects, such as stimulation, euphoria, wellbeing, enhanced empathy, and altered perception. Methylone exhibited an effect profile similar to MDMA, with a faster overall onset and earlier disappearance of subjective effects. These results suggest that abuse potential of methylone is comparable to that of MDMA in humans. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT05488171; Identifier: NCT05488171.

Neurological and cognitive alterations induced by MDMA in humans

3,4 Methylenedioxymethamphetamine generally referred to as MDMA or 'ecstasy' is a ring-substituted phenethylamine stimulant which produces powerful empathogenic effects. Use of MDMA remains popular despite prohibition, and potential long-term negative consequences of repeated use. MDMA produces its acute subjective effects primarily by stimulating the release of serotonin via action at the serotonin transporter (SERT). There is evidence that MDMA administration may lead to long lasting neurotoxic effects on serotonin neurons in primates, and reductions in markers of central serotonin axons, and axon terminals in animals. In humans, demonstration of serotonergic neurotoxicity is much more difficult to identify, and much of the research is complicated by confounding issues of polysubstance use, genetic and environmental factors and reliance on self-reports of previous drug use. We do not review the mechanisms for neurotoxicity in detail as they are covered elsewhere in this special issue. There is a large body of literature, however, which has investigated potential cognitive and neurocognitive consequences of repeated MDMA use. Here we review the literature on cognition, and neuroimaging studies that have investigated structural and functional brain changes associated with ecstasy use.

Drug liking and wanting, not impulsive action or reflection is increased by 4-fluoroamphetamine

BACKGROUND

New psychoactive substances (NPS) are chemical analogues designed to mimic the effects of various classic recreational drugs of abuse including MDMA, LSD, and cannabis. NPS use is associated with concern about the acute and longer-term effects particular substances might have, with abuse and addiction as potential consequences. Impulsivity and sensitivity to the rewarding effects of drugs have been considered as risk factors for drug abuse. In light of the popularity of 4-fluoroamphetamine (4-FA), it is important to assess whether 4-FA can lead to subjective drug liking and wanting, and impulsive behavior, all factors contributing to the abuse likelihood of a substance.

METHODS

A placebo-controlled 2-way crossover study in 12 healthy poly-drug using participants was conducted to test subjective and behavioral effects of 4-FA (100 mg). 4-FA concentrations were determined in serum up to 12 h after administration and two impulsivity tasks and two drug experience questionnaires assessing drug liking and wanting, and good and bad drug effect, were administered between 1 and 11 h post-administration.

RESULTS

Findings showed that 4-FA did not affect impulsive behavior. Self-ratings of drug liking and wanting and good drug effect were increased 1 h after administration; this effect was absent 11 h after drug intake.

DISCUSSION AND CONCLUSION

To conclude, 4-FA (single dose) increased self-rated liking and wanting, which is known to contribute to the abuse likelihood of a substance; however, it left another factor impulsive behavior unaffected. It has to be noted that the current picture is limited and might change with increased sample size, and/or different 4-FA doses.

CLINICAL TRIAL REGISTRATION

Trial acronym: 4-FA. URL: http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=6164 . Registration number: NTR6164 (Dutch clinical trial registry number).

Effects of total sleep deprivation on divided attention performance

Dividing attention across two tasks performed simultaneously usually results in impaired performance on one or both tasks. Most studies have found no difference in the dual-task cost of dividing attention in rested and sleep-deprived states. We hypothesized that, for a divided attention task that is highly cognitively-demanding, performance would show greater impairment during exposure to sleep deprivation. A group of 30 healthy males aged 21-30 years was exposed to 40 h of continuous wakefulness in a laboratory setting. Every 2 h, subjects completed a divided attention task comprising 3 blocks in which an auditory Go/No-Go task was 1) performed alone (single task); 2) performed simultaneously with a visual Go/No-Go task (dual task); and 3) performed simultaneously with both a visual Go/No-Go task and a visually-guided motor tracking task (triple task). Performance on all tasks showed substantial deterioration during exposure to sleep deprivation. A significant interaction was observed between task load and time since wake on auditory Go/No-Go task performance, with greater impairment in response times and accuracy during extended wakefulness. Our results suggest that the ability to divide attention between multiple tasks is impaired during exposure to sleep deprivation. These findings have potential implications for occupations that require multi-tasking combined with long work hours and exposure to sleep loss.

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.

Changes in serotonin transporter (5-HTT) gene expression in peripheral blood cells after MDMA intake

RATIONALE

3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) is an amphetamine derivative abused worldwide. Although data report that relatively high doses of MDMA deplete serotonin (5-HT) content and decrease the availability of serotonin transporters (5-HTT), there is no available evidence as to the adaptive mechanisms taking place in 5-HTT gene expression following MDMA intake in humans.

OBJECTIVE

To evaluate the pharmacological effects of MDMA on 5-HTT gene expression, using peripheral mononuclear cells as a biomarker of the central nervous system, and study whether an association exists between 5-HTT gene expression and psychobiological scores.

METHODS

A randomized, double-blind, controlled trial was conducted in 18 (nine women) healthy recreational MDMA users. Subjects were genotyped for 5-HTT linked polymorphism region (5-HTTLPR). MDMA 75 mg or placebo was administered; Profile of Mood States (POMS) and 5-HTT gene expression measures were performed at baseline, 90, and 165 min post administration. POMS scores were correlated with changes in gene expression.

RESULTS

The administration of 75 mg MDMA induced a significant twofold increase in 5-HTT gene expression after 165 min of drug administration. Significant associations were found between gene expression and POMS scores after MDMA administration. Results for each gender and 5-HTTLPR genotype are also reported.

CONCLUSIONS

Preliminary results show that MDMA causes substantial regulatory changes in the expression of serotonergic markers, likely being modulated by the 5-HTTLPR polymorphism. Changes in 5-HTT gene expression may play an important role in the regulation of mood state.

Sensitivity and validity of psychometric tests for assessing driving impairment: effects of sleep deprivation

OBJECTIVE

To assess drug induced driving impairment, initial screening is needed. However, no consensus has been reached about which initial screening tools have to be used. The present study aims to determine the ability of a battery of psychometric tests to detect performance impairing effects of clinically relevant levels of drowsiness as induced by one night of sleep deprivation.

METHODS

Twenty four healthy volunteers participated in a 2-period crossover study in which the highway driving test was conducted twice: once after normal sleep and once after one night of sleep deprivation. The psychometric tests were conducted on 4 occasions: once after normal sleep (at 11 am) and three times during a single night of sleep deprivation (at 1 am, 5 am, and 11 am).

RESULTS

On-the-road driving performance was significantly impaired after sleep deprivation, as measured by an increase in Standard Deviation of Lateral Position (SDLP) of 3.1 cm compared to performance after a normal night of sleep. At 5 am, performance in most psychometric tests showed significant impairment. As expected, largest effect sizes were found on performance in the Psychomotor Vigilance Test (PVT). Large effects sizes were also found in the Divided Attention Test (DAT), the Attention Network Test (ANT), and the test for Useful Field of View (UFOV) at 5 and 11 am during sleep deprivation. Effects of sleep deprivation on SDLP correlated significantly with performance changes in the PVT and the DAT, but not with performance changes in the UFOV.

CONCLUSION

From the psychometric tests used in this study, the PVT and DAT seem most promising for initial evaluation of drug impairment based on sensitivity and correlations with driving impairment. Further studies are needed to assess the sensitivity and validity of these psychometric tests after benchmark sedative drug use.

The acute effects of MDMA and ethanol administration on electrophysiological correlates of performance monitoring in healthy volunteers

RATIONALE

Knowing how commonly used drugs affect performance monitoring is of great importance, because drug use is often associated with compromised behavioral control. Two of the most commonly used recreational drugs in the western world, 3,4-methylenedioxymethamphetamine (MDMA or "ecstasy") and ethanol (alcohol), are also often used in combination. The error-related negativity (ERN), correct-related negativity (CRN), and N2 are electrophysiological indices of performance monitoring.

OBJECTIVES

The present study aimed to investigate how ethanol, MDMA, and their co-administration affect performance monitoring as indexed by the electrophysiological correlates.

METHODS

Behavioral and EEG data were obtained from 14 healthy volunteers during execution of a speeded choice-reaction-time task after administration of ethanol, MDMA, and combined ethanol and MDMA, in a double-blind, placebo-controlled, randomized crossover design.

RESULTS

Ethanol significantly reduced ERN amplitudes, while administration of MDMA did not affect the ERN. Co-administration of MDMA and ethanol did not further impair nor ameliorate the effect of ethanol alone. No drug effects on CRN nor N2 were observed.

DISCUSSION

A decreased ERN following ethanol administration is in line with previous work and offers further support for the impairing effects of alcohol intoxication on performance monitoring. This impairment may underlie maladaptive behavior in people who are under influence. Moreover, these data demonstrate for the first time that MDMA does not affect performance monitoring nor does it interact with ethanol in this process. These findings corroborate the notion that MDMA leaves central executive functions relatively unaffected.

Interactions between disordered sleep, post-traumatic stress disorder, and substance use disorders

Disordered sleep is associated with a number of adverse health consequences and is an integral component of many psychiatric disorders. Rates of substance use disorders (SUDs) are markedly higher among individuals with post-traumatic stress disorder (PTSD), and this relationship may be partly mediated by disturbed sleep. Sleep disturbances (e.g. insomnia, daytime sleepiness, vivid nightmares) are hallmark features of PTSD and there is evidence that individuals with PTSD engage in substance use as a means of coping with these symptoms. However, prolonged substance use can lead to more severe sleep disturbances due to the development of tolerance and withdrawal. Behavioural or pharmacological treatment of disordered sleep is associated with improved daytime symptoms and psychosocial functioning among individuals who have developed PTSD. Initial research also suggests that improving sleep could be similarly beneficial in reducing coping oriented substance use and preventing relapse among those seeking treatment for SUDs. Together, these findings suggest that ameliorating sleep disturbance among at-risk individuals would be a viable target for the prevention and treatment of PTSD and associated SUDs, but prospective research is needed to examine this hypothesis. Enhanced understanding of the interrelation between sleep, PTSD, and SUDs may yield novel prevention and intervention approaches for these costly, prevalent and frequently co-occurring disorders.

Human pharmacology of 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) after repeated doses taken 2 h apart

BACKGROUND

3,4-methylenedioxymethamphetamine (MDMA, ecstasy) is one of the most abused recreational drugs. Its usual pattern of misuse includes repeated doses taken over a short time period that could influence MDMA pharmacology and toxicity.

OBJECTIVE

This study aims to evaluate the pharmacokinetics and pharmacologically induced effects of two MDMA consecutive doses separated by 2 h.

METHODS

A randomized, double-blind, crossover, and placebo-controlled trial included ten male volunteers participating in two experimental sessions. MDMA was administered as a single 100-mg dose or as a repeated dose (50 mg followed by 100 mg, administered at 2 h apart). Outcome variables included pharmacokinetics, physiological, subjective, and psychomotor effects.

RESULTS

Following the repeated doses, plasma concentrations of MDMA were higher than those expected by simple dose accumulation (+16.2 % AUC; +12.8 % C (max)), but those of HMMA and HMA were significantly lower (-29.8 % AUC; -38.2 % C (max)). After the second dose, physiological effects, psychomotor performance, and subjective effects were lower than expected especially for euphoria and stimulation. MDMA-induced increases in diastolic and systolic arterial pressure and body temperature were in the range of those expected following MDMA concentrations.

CONCLUSIONS

MDMA pharmacokinetics and metabolic disposition following two doses separated by 2 h show that the contribution of the first dose to the MDMA-induced mechanism-based metabolic inhibition was already apparent. The concentrations of MDMA after the second dose were slightly higher than expected. The effects on blood pressure and temperature after the second administration were slightly higher than those following the first, but for heart rate and subjective variables these were lower than expected considering the MDMA concentrations achieved, suggesting a possible tolerance phenomenon.

Psychomotor function in chronic daily Cannabis smokers during sustained abstinence

Background

The present study assessed psychomotor function in chronic, daily cannabis smokers during 3 weeks continuously monitored abstinence on a secure research unit. We hypothesized that psychomotor performance would improve during abstinence of chronic, daily cannabis smokers.

Methodology/Principal Findings

Performance on the critical tracking (CTT) and divided attention (DAT) tasks was assessed in 19 male chronic, daily cannabis smokers at baseline and after 8, 14–16 and 21–23 days of continuously monitored abstinence. Psychomotor performance was compared to a control group of non-intoxicated occasional drug users. Critical frequency (λ_c) of the CTT and tracking error and control losses of the DAT were the primary outcome measures. Results showed that chronic cannabis smokers’ performance on the CTT (p<0.001) and the DAT (p<0.001) was impaired during baseline relative to the comparison group. Psychomotor performance in the chronic cannabis smokers improved over 3 weeks of abstinence, but did not recover to equivalent control group performance.

Conclusions/Significance

Sustained cannabis abstinence moderately improved critical tracking and divided attention performance in chronic, daily cannabis smokers, but impairment was still observable compared to controls after 3 weeks of abstinence. Between group differences, however, need to be interpreted with caution as chronic smokers and controls were not matched for education, social economic status, life style and race.

Effects of acute MDMA intoxication on mood and impulsivity: role of the 5-HT2 and 5-HT1 receptors

MDMA induces positive mood and increases impulse control during intoxication, but only a few studies on the neuropharmacological mechanisms underlying these processes have been conducted. It was hypothesized that pretreatment with 5-HT₁ and 5-HT₂ receptor blockers would prevent MDMA effects on mood and impulsivity. Subjects (N = 17) participated in a double-blind, placebo controlled, within-subject design involving 6 experimental conditions consisting of pretreatment (T1) and treatment (T2). T1 preceded T2 by 30 minutes. T1–T2 combinations were: placebo-placebo, 20 mg pindolol-placebo, 50 mg ketanserin-placebo, placebo-75 mg MDMA, 20 mg pindolol-75 mg MDMA and 50 mg ketanserin-75 g MDMA. Subjects completed a Profile of Mood States (POMS) questionnaire and several impulsivity tasks (Stop signal task, Matching familiar figures task, Cue dependent reversal learning task) at 1.5 hrs post-treatment. MDMA alone increased both positive (vigor, arousal, friendliness, elation, positive mood) and negative affect (anxiety, confusion) as assessed by the POMS questionnaire. MDMA also increased stop reaction time in the Stop signal task and reaction time in the Matching familiar figures task. Pretreatment with ketanserin blocked MDMA effects on positive affect, but not negative affect. Ketanserin did not influence the effects of MDMA on impulsivity. Pindolol did not interact with MDMA on any of the measures. In conclusion, 5-HT₂ receptors mediate positive moods induced by MDMA but not negative moods or impulsivity. 5-HT₁ receptors do not appear to be involved in MDMA effects on mood and impulse control.

Mephedrone (4-methylmethcathinone, 'meow'): acute behavioural effects and distribution of Fos expression in adolescent rats

Mephedrone (4-methylmethcathinone) is a novel recreational drug that has rapidly increased in popularity in recent years. Users report mephedrone as having the stimulant-like qualities of methamphetamine and cocaine, combined with the prosocial, entactogenic effects of 3,4-methylenedioxymethamphetamine (MDMA). Anecdotal and case study reports indicate that mephedrone may have the potential to engender compulsive patterns of use as well as toxicity in overdose. However, there have been almost no neuropharmacological investigations of the drug up to this point. Here we examined the effects of two different mephedrone doses [15 and 30 mg/kg, intraperitoneal (IP)] relative to the well-known stimulant methamphetamine (2 mg/kg IP) in adolescent rats. Rats were injected, assessed for locomotor activity for 60 minutes and then tested in a 10-minute social preference test (measuring time spent in close proximity to a real rat versus a dummy rat). Their brains were then processed using Fos immunohistochemistry to determine patterns of brain activation. Results showed that mephedrone caused profound locomotor hyperactivity at both dose levels while tending to reduce social preference. Patterns of Fos expression with mephedrone resembled a combination of those observed with methamphetamine and MDMA, with particularly strong Fos expression in the cortex, dorsal and ventral striatum, ventral tegmental area (typical of both MDMA and methamphetamine) and supraoptic nucleus (typical of MDMA). These results demonstrate for the first time the powerful stimulant effects of mephedrone in animal models and its capacity to activate mesolimbic regions. These results also provide some empirical basis to user reports that mephedrone subjectively resembles a MDMA/methamphetamine hybrid.

Driving under the influence of amphetamine-like drugs

Scientific opinions differ whether the use of stimulants causes deterioration in driving skills. In 1857 of 8709 cases of driving under the influence of drugs, amphetamine-like drugs (amphetamine, methamphetamine, and methylendioxyamphetamine) were present either alone or together with other licit or illicit drugs. In 338 cases, amphetamines were the only psychoactive substance group in plasma at mean, median, and highest concentrations of 0.18, 0.12, and 1.05 mg/L, respectively. A widespread opinion is that after the consumption of amphetamines, centrally stimulating effects with corresponding consequences on safe driving are expected. In contrast, many cases were observed that rather suggested an influence of centrally sedating substances when considering the psycho-physical conditions. Relations between concentration and effect could not be established. The apparent sedation is probably the consequence of sleep deprivation during an amphetamine binge and the after-effects of the drug.

MDMA (ecstasy) effects on actual driving performance before and after sleep deprivation, as function of dose and concentration in blood and oral fluid

RATIONALE

Experimental research has shown that 3,4-methylenedioxymethamphetamine (MDMA) can improve some psychomotor driving skills when administered during the day. In real life, however, MDMA is taken during the night, and driving may likely occur early in the morning after a night of "raving" and sleep loss.

OBJECTIVES

The present study assessed the effects of MDMA on road-tracking and car-following performance in on-the-road driving tests in normal traffic.

METHODS

Sixteen recreational MDMA users participated in a randomized double-blind placebo-controlled four-way cross-over design. They received single, evening doses of 0, 25, 50, and 100 mg MDMA on separate occasions. Actual driving tests were conducted in the evening when MDMA serum concentrations were maximal and in the morning after a night of sleep loss.

RESULTS

The primary measure of driving, i.e., standard deviation of lateral position (SDLP, a measure of weaving) was significantly increased during driving tests in the morning in all treatment conditions, irrespective of MDMA dose and concentration. The increments in SDLP were of high clinical relevance and comparable to those observed for alcohol at blood alcohol concentrations >0.8 mg/mL. These impairments were primarily caused by sleep loss.

CONCLUSIONS

In general, MDMA did not affect driving performance nor did it change the impairing effects of sleep loss. It is concluded that MDMA cannot compensate for the impairing effects of sleep loss and that drivers who are under the influence of MDMA and sleep deprived are unfit to drive.

Effects of alcohol (BAC 0.5‰) and ecstasy (MDMA 100 mg) on simulated driving performance and traffic safety

RATIONAL

An increasing number of fatal road-accidents have been reported in which ecstasy was found in the blood of drivers. Although, ecstasy is frequently found to have been used in combination with alcohol, studies on the acute effects of ecstasy co-administered with alcohol on driving performance are relatively rare.

OBJECTIVE

The present study was designed to establish the extent of driver impairment as a consequence of ecstasy or combined ecstasy and alcohol use as compared to driving under the influence of 0.3‰, 0.5‰ and 0.8‰ alcohol. Furthermore, subjective performance was also assessed.

RESULTS

Alcohol and ecstasy mainly influenced automated driving performance such as lateral and speed control. However, small to no effects of the substances were found on more complex driving behaviour. Overall, variance within the different driving measures was high especially when participants were treated with 3.4-methylenedioxy-methamphetamine (MDMA) and alcohol. Furthermore, equivalence testing showed that combined use may lead to impaired driving for some, but not all, drivers. Participants rated their own performance to be slightly worse than normal in both studies. Since driving was actually seriously deteriorated, this was a falsely positive assessment of their condition.

CONCLUSIONS

The dissociation between subjective perceptions and objective performance decrements are important notions for traffic safety since this may affect a driver's judgement of whether or not it is safe to drive. For example, an intoxicated individual might decide to drive because the feelings of alertness caused by MDMA cloud the impairing effects of other drugs such as alcohol, thereby creating a potentially serious risk for traffic safety.

Dose-related effects of MDMA on psychomotor function and mood before, during, and after a night of sleep loss

INTRODUCTION

3,4-methylenedioxymethamphetamine (MDMA) is known to improve psychomotor function and mood when measured during daytime. However, MDMA users tend to take this drug at dance parties while staying awake for prolonged periods of time.

SUBJECTS AND METHODS

This study was designed to assess dose-related residual effects of MDMA on psychomotor function and mood after a night without sleep. Sixteen recreational MDMA users received single doses of 25, 50, and 100 mg MDMA in a randomized, double-blind, placebo-controlled cross-over study.

RESULTS

Results showed that sleep loss significantly impaired psychomotor function. MDMA generally did not affect performance but did improve rapid information processing at the highest dose in the morning after administration. In the evening, MDMA also increased subjective ratings of positive mood at every dose and subjective arousal at the highest dose. These subjective effects were no longer present after a night of sleep loss.

DISCUSSION

It is concluded that sleep deprivation impairs psychomotor function and that stimulant effects of MDMA are not sufficient to compensate for this impairment.

Memory and mood during the night and in the morning after repeated evening doses of MDMA

Previously it has been shown that MDMA causes memory impairment during daytime testing. However, MDMA is usually taken in the evening or during the night. In addition, it is known that sleep deprivation also causes memory impairment. The present study aimed to assess whether evening doses of MDMA added to, or interacted with the memory impairment due to sleep deprivation. Fourteen healthy subjects participated in a double-blind, placebo-controlled, two-way cross-over study. Treatments consisted of MDMA 75 and 50 mg divided over the evening or double placebo. Memory tests and subjective measures of mood were conducted at baseline and three times post dosing that is at 6.30 pm, 9.30 pm, 1.30 am and 7 am, respectively -1.5, 1.5, 5.5 and 11 h relative to drug intake (first dose). Memory performance detoriated progessively over time as a function of sleep loss, independent of treatment. MDMA added to this impairment as indicated by a significant main effect of MDMA on verbal and spatial memory performance. Mood ratings and response speed revealed an MDMA by Time interaction. After administration of MDMA response speed improved and feelings of vigor, friendliness, elation, anxiety, confusion, arousal and positive mood increased in magnitude during the night, while all these parameters returned to placebo-like levels on the final morning session. It is concluded that evening doses of MDMA selectively impair memory performance, and that this impairment is additional to the effect of sleep deprivation on memory performance.

Acute neuropsychological effects of MDMA and ethanol (co-)administration in healthy volunteers

RATIONALE

In Western societies, a considerable percentage of young people expose themselves to 3,4-methylenedioxymethamphetamine (MDMA or "ecstasy"). Commonly, ecstasy is used in combination with other substances, in particular alcohol (ethanol). MDMA induces both arousing as well as hallucinogenic effects, whereas ethanol is a general central nervous system depressant.

OBJECTIVE

The aim of the present study is to assess the acute effects of single and co-administration of MDMA and ethanol on executive, memory, psychomotor, visuomotor, visuospatial and attention function, as well as on subjective experience.

MATERIALS AND METHODS

We performed a four-way, double-blind, randomised, crossover, placebo-controlled study in 16 healthy volunteers (nine male, seven female) between the ages of 18-29. MDMA was given orally (100 mg) and blood alcohol concentration was maintained at 0.6 per thousand by an ethanol infusion regime.

RESULTS

Co-administration of MDMA and ethanol was well tolerated and did not show greater impairment of performance compared to the single-drug conditions. Impaired memory function was consistently observed after all drug conditions, whereas impairment of psychomotor function and attention was less consistent across drug conditions.

CONCLUSIONS

Co-administration of MDMA and ethanol did not exacerbate the effects of either drug alone. Although the impairment of performance by all drug conditions was relatively moderate, all induced significant impairment of cognitive function.