The sub-acute effects of recreational ecstasy (MDMA) use: a controlled study in humans

Framing substance use as "recreational" is neither accurate nor helpful for prevention purposes

This debate paper discusses six reasons why the term "recreational substance use" should be avoided. (1) Social norms and beliefs are drivers of behavior; therefore, the normalized use of the term conveys injunctive norms of a fully socially acceptable substance. Injunctive norms are the most important drivers of initiation into substance use. (2) The illusion of being in control, suggesting that if consumed for leisure and recreation it can easily be controlled; (3) Idealized social representations that fuel an idealized image of an alternative glamourous or mindful consumption culture; (4) Downplaying potential harms; (5) The implicit promise of everyday pleasure, the ever-growing potency of cannabis products does not fit the narrative of its use for recreation; (6) Industry as a trojan horse branding discourse of the concept of medical cannabis to normalize the image of non-medical use: to complement "therapeutic" with "recreational". "Recreational use" is a subjective ill-defined term. This debate paper aims to find a better terminological solution, honestly denominating with a neutral, unbiased, and objective connotation what is now called "recreational use". Thus, we propose using the term "non-therapeutic" use.

Methylenedioxymethamphetamine (MDMA): Serotonergic and dopaminergic mechanisms related to its use and misuse

Methylenedioxymethamphetamine (MDMA) is an amphetamine analogue that preferentially stimulates the release of serotonin (5HT) and results in relatively small increases in synaptic dopamine (DA). The ratio of drug-stimulated increases in synaptic DA, relative to 5HT, predicts the abuse liability; drugs with higher DA:5HT ratios are more likely to be abused. Nonetheless, MDMA is a drug that is misused. Clinical and preclinical studies have suggested that repeated MDMA exposure produces neuroadaptive responses in both 5HT and DA neurotransmission that might explain the development and maintenance of MDMA self-administration in some laboratory animals and the development of a substance use disorder in some humans. In this paper, we describe the research that has demonstrated an inhibitory effect of 5HT on the acquisition of MDMA self-administration and the critical role of DA in the maintenance of MDMA self-administration in laboratory animals. We then describe the circuitry and 5HT receptors that are positioned to modulate DA activity and review the limited research on the effects of MDMA exposure on these receptor mechanisms.

Who is the typical psychedelics user? Methodological challenges for research in psychedelics use and its consequences

Aims:

This article argues that despite a resurgence in research on psychedelics over the last two decades, we still have little insight into the psychedelics user population. Furthermore, there is currently little agreement between researchers as to the long-term mental health consequences of psychedelics use.

Design:

In a methodological review of a range of studies in psychedelics use, it is demonstrated that these studies tend to focus on specific segments of the user population while excluding others. These population segments are probably connected to different patterns of use, which in turn are likely to result in different long-term consequences.

Results:

The divergent findings on the consequences of psychedelics use may be explained, at least in part, by the fact that different research strategies explore different segments of the user population. Studies focusing on user segments with problematic usage patterns tend to find that psychedelics use is negative for mental health, while studies on infrequent users tend to find that psychedelics use is positive for mental health.

Conclusion:

Because the field of psychedelics studies lacks a reliable model of the user population, it is difficult for researchers to contextualise and assess the broader validity of their findings. To remedy this situation, the article presents three theoretical models of the user population that afford us with tentative means of contextualising findings and thereby may clarify present disagreements.

Substance usage intention does not affect attentional bias: implications from Ecstasy/MDMA users and alcohol drinkers

BACKGROUND

An attentional bias towards substance-related stimuli has been demonstrated with alcohol drinkers and many other types of substance user. There is evidence to suggest that the strength of an attentional bias may vary as a result of context (or use intention), especially within Ecstasy/MDMA users.

OBJECTIVE

Our aim was to empirically investigate attentional biases by observing the affect that use intention plays in recreational MDMA users and compare the findings with that of alcohol users.

METHOD

Regular alcohol drinkers were compared with MDMA users. Performance was assessed for each group separately using two versions of an eye-tracking attentional bias task with pairs of matched neutral, and alcohol or MDMA-related visual stimuli. Dwell time was recorded for alcohol or MDMA. Participants were tested twice, when intending and not intending to use MDMA or alcohol. Note, participants in the alcohol group did not complete any tasks which involved MDMA-related stimuli and vice versa.

RESULTS

Significant attentional biases were found with both MDMA and alcohol users for respective substance-related stimuli, but not control stimuli. Critically, use intention did not affect attentional biases. Attentional biases were demonstrated with both MDMA users and alcohol drinkers when usage was and was not intended.

CONCLUSIONS

These findings demonstrate the robust nature of attentional biases i.e. once an attentional bias has developed, it is not readily affected by intention.

Methylenedioxymethamphetamine (MDMA) in Psychiatry: Pros, Cons, and Suggestions

BACKGROUND

For a number of mental health disorders, including posttraumatic stress disorders (PTSD), there are not many available treatment options. Recently, there has been renewed interest in the potential of methylenedioxymethamphetamine (MDMA) to restore function for patients with these disorders. The primary hypothesis is that MDMA, via prosocial effects, increases the ability of patients to address the underlying psychopathology of the disorder. However, the use of MDMA poses potential problems of neurotoxicity, in addition to its own potential for misuse.

METHODS

In this article, the proposed potential of MDMA as an adjunct to psychotherapy for PTSD is evaluated. The rationale for the use of MDMA and the positive results of studies that have administered MDMA in the treatment of PTSD are provided (pros). A description of potential adverse effects of treatment is also presented (cons). An overview of MDMA pharmacology and pharmacokinetics and a description of potential adverse effects of treatments are also presented. Methylenedioxymethamphetamine-produced oxytocin release and decreased expression of fear conditioning as well as one of the MDMA enantiomers (the n R- entaniomer) are suggested as potential mechanisms for the beneficial effects of MDMA in PTSD (suggestions).

RESULTS

There is some evidence that MDMA facilitates recovery of PTSD. However, the significant adverse effects of MDMA raise concern for its adoption as a pharmacotherapy. Alternative potential treatments with less adverse effects and that are based on the ubiquitous pharmacology of MDMA are presented.

CONCLUSIONS

We suggest that additional research investigating the basis for the putative beneficial effects of MDMA might reveal an effective treatment with fewer adverse effects. Suggestions of alternative treatments based on the behavioral pharmacology and toxicology of MDMA and its enantiomers are presented.

An observational study on the sub-acute effects of mephedrone on mood, cognition, sleep and physical problems in regular mephedrone users

RATIONALE

Mephedrone (4-methylmethcathinone; 4-MMC) is a novel recreational drug similar to methylenedioxymethamphetamine (MDMA) and amphetamine. Several adverse effects have been reported, but little is known about its sub-acute effects.

OBJECTIVES

To study sub-acute effects of mephedrone over a period of 9 days.

METHODS

Recreational mephedrone users were recruited and followed over a time period of 9 days. It was recorded whether participants consumed mephedrone or not within the period of testing; those who did were compared to those who did not. Forty-six regular mephedrone users (22 males, 24 females) participated, 21 participants voluntarily opted to consume mephedrone 1-3 days after baseline and 25 opted to abstain. Participants were assessed at baseline on a multitude of measures and provided daily reports on cognition, sleep, mood, physical problems, mephedrone cravings and substance use on each subsequent day of the study. The study controlled for psychopathology, sleep, past and current substance use, impulsivity and demographics.

RESULTS

Those who consumed mephedrone reported persistent negative mood, physical problems and fatigue, compared to those who did not-after controlling for baseline group differences in sleep and subsequent alcohol and cannabis use.

CONCLUSIONS

The results provide the first prospective evidence of the duration and extent of specific undesirable sub-acute effects of mephedrone in regular recreational users and indicate sub-acute effects of mephedrone on mood, fatigue and physical symptoms.

Acute effects of 3,4-methylenedioxymethamphetamine (MDMA) and R(-) MDMA on actigraphy-based daytime activity and sleep parameters in rhesus monkeys

3,4-Methylenedioxymethamphetamine (MDMA) affects monoaminergic pathways that play a critical role in sleep-wake cycles. Dopaminergic mechanisms are thought to mediate the sleep-disrupting effects of stimulant drugs. However, the mechanisms underlying the effects of MDMA on sleep-wake cycles and the effects of R(-) MDMA, a stereoisomer that lacks dopaminergic activity, on sleep remain unknown. The aim of the present study was to investigate the effects of racemic MDMA and R(-) MDMA on daytime activity and sleep-like parameters evaluated with actigraphy in adult rhesus macaques (Macaca mulatta, n = 6). Actiwatch monitors were attached to the monkeys' collars and actigraphy recording was conducted during baseline conditions and after the administration of acute intramuscular injections of saline (vehicle), racemic MDMA (0.3, 1.0, or 1.7 mg/kg), or R(-) MDMA (0.3, 1.0, or 1.7 mg/kg) at 9 or 16 h (3 h before "lights off"). Morning treatments had no effects on sleep-like parameters. Racemic MDMA decreased general daytime activity during the first hour after injection and increased daytime activity at 3 hr posttreatment. Although afternoon administration of racemic MDMA increased sleep latency, it improved other sleep parameters, decreasing wake time after sleep onset (WASO) and increasing sleep efficiency for subjects with low baseline sleep efficiency. Afternoon treatment with R(-) MDMA improved sleep measures, increasing sleep efficiency and decreasing sleep latency and WASO, while having no effects on daytime activity. The stimulant and sleep-disrupting effects of racemic MDMA are likely mediated by dopaminergic and noradrenergic mechanisms, while serotonergic pathways appear to be involved in the sleep-promoting effects of MDMA. (PsycINFO Database Record

The 21st century psychedelic renaissance: heroic steps forward on the back of an elephant

Given the plethora of new studies and published papers in the scientific press and the increasingly emerging presence of articles about positive psychedelic experiences appearing in the popular media, there is little doubt that we are in the midst of a Psychedelic Renaissance. The classical psychedelic drugs LSD and psilocybin and the entactogen MDMA are showing promise as tools to assist psychotherapy for a wide range of mental disorders, with multiple pilot studies demonstrating their safety and efficacy. In this article, the author describes how MDMA in particular has inherent characteristics that make it well suited for assisting trauma-focused psychotherapy in a population of patients who have experienced child abuse. But despite these advances, there remain many obstacles ahead of the widespread mainstream acceptance of psychedelic medicines. The author argues that the Misuse of Drugs Act 1971 is one such obstacle. Other impediments include a prevailing attitude of pseudoscience and rigidity from within the non-scientific psychedelic community itself. Resolution of these conflicts must be sought if medicine and society are to see psychedelics gaining a place in mainstream culture and science.

Why Psychiatry Needs 3,4-Methylenedioxymethamphetamine: A Child Psychiatrist's Perspective

Since the late 1980s the psychoactive drug 3,4-methylenedioxymethamphetamine (MDMA) has had a well-known history as the recreationally used drug ecstasy. What is less well known by the public is that MDMA started its life as a therapeutic agent and that in recent years an increasing amount of clinical research has been undertaken to revisit the drug's medical potential. MDMA has unique pharmacological properties that translate well to its proposed agent to assist trauma-focused psychotherapy. Psychological trauma-especially that which arises early in life from child abuse-underpins many chronic adult mental disorders, including addictions. Several studies of recent years have investigated the potential role of MDMA-assisted psychotherapy as a treatment for post-traumatic stress disorder, with ongoing plans to see MDMA therapy licensed and approved within the next 5 years. Issues of safety and controversy frequently surround this research, owing to MDMA's often negative media-driven bias. However, accurate examination of the relative risks and benefits of clinical MDMA-in contrast to the recreational use of ecstasy-must be considered when assessing its potential benefits and the merits of future research. In this review, the author describes these potential benefits and explores the relatives risks of MDMA-assisted psychotherapy in the context of his experience as a child and adolescent psychiatrist, having seen the relative limitations of current pharmacotherapies and psychotherapies for treating complex post-traumatic stress disorder arising from child abuse.

Contribution of Impulsivity and Serotonin Receptor Neuroadaptations to the Development of an MDMA ('Ecstasy') Substance Use Disorder

As is the case with other drugs of abuse, a proportion of ecstasy users develop symptoms consistent with a substance use disorder (SUD). In this paper, we propose that the pharmacology of MDMA, the primary psychoactive component of ecstasy tablets, changes markedly with repeated exposure and that neuroadaptations in dopamine and serotonin brain systems underlie the shift from MDMA use to MDMA misuse in susceptible subjects. Data from both the human and laboratory animal literature are synthesized to support the idea that (1) MDMA becomes a less efficacious serotonin releaser and a more efficacious dopamine releaser with the development of behaviour consistent with an SUD and (2) that upregulated serotonin receptor mechanisms contribute to the development of the MDMA SUD via dysregulated inhibitory control associated with the trait of impulsivity.

MDMA-assisted therapy: A new treatment model for social anxiety in autistic adults

The first study of 3,4-methylenedioxymethamphetamine (MDMA)-assisted therapy for the treatment of social anxiety in autistic adults commenced in the spring of 2014. The search for psychotherapeutic options for autistic individuals is imperative considering the lack of effective conventional treatments for mental health diagnoses that are common in this population. Serious Adverse Events (SAEs) involving the administration of MDMA in clinical trials have been rare and non-life threatening. To date, MDMA has been administered to over 1133 individuals for research purposes without the occurrence of unexpected drug-related SAEs that require expedited reporting per FDA regulations. Now that safety parameters for limited use of MDMA in clinical settings have been established, a case can be made to further develop MDMA-assisted therapeutic interventions that could support autistic adults in increasing social adaptability among the typically developing population. As in the case with classic hallucinogens and other psychedelic drugs, MDMA catalyzes shifts toward openness and introspection that do not require ongoing administration to achieve lasting benefits. This infrequent dosing mitigates adverse event frequency and improves the risk/benefit ratio of MDMA, which may provide a significant advantage over medications that require daily dosing. Consequently, clinicians could employ new treatment models for social anxiety or similar types of distress administering MDMA on one to several occasions within the context of a supportive and integrative psychotherapy protocol.

Subacute effects of ecstasy on mood: an exploration of associated risk factors

Ecstasy use may result in lowered mood, anxiety or aggression in the days following use. Yet, few studies have investigated what factors increase the risk of experiencing such symptoms. Ecstasy users (at least once in the last 12 months) who subsequently took ecstasy (n=35) over the period of one week, were compared on measures of mood, sleep, stress and drug use, with those who abstained from ecstasy (n=21) that week. Measures were administered the week prior to ecstasy use and one and three days following use, or the equivalent day for abstainers. Mood symptoms were assessed using the Kessler-10 self-report psychological distress scale, a subjective mood rating (1-10), and using the depression, anxiety and hostility items from the clinician-rated Brief Psychiatric Rating Scale. Timeline Followback methods were used to collect information on drug use and life stress in the past month. Self-reported sleep quality was also assessed. Ecstasy use was not associated with subacute depressive, anxiety or aggressive symptoms. Rather, lowered mood and increased psychological distress were associated with self-reported hours and quality of sleep obtained during the three-day follow-up. These findings highlight the importance of considering sleep disruption in understanding the short-term mood effects of ecstasy use.

MDMA induces Per1, Per2 and c-fos gene expression in rat suprachiasmatic nuclei

RATIONALE

±3,4-Methylenedioxymethamphetamine (MDMA, 'ecstasy') is a psychoactive drug that has marked effects on the serotonergic system. Serotonergic agonists are known to interact with the circadian pacemaker located in the suprachiasmatic nuclei (SCN).

OBJECTIVES

Given changes reported in the behavioral activity rhythm following MDMA treatment, the effects of MDMA on core clock gene (Per1, Per2) and c-fos expression were evaluated.

METHODS

Male Long-Evans rats (n = 72) were injected once with MDMA (5 mg/kg i.p.) or saline either at the middle of their 'rest' phase (Zeitgeber Time: ZT6) or the middle of their 'active' phase (Zeitgeber Time: ZT16) and killed at 30, 60, or 120 min posttreatment for gene expression analysis in the SCN using PCR. Behavioral rhythms of a separate group of rats (n = 20) were measured following treatment at ZT16 while they were held in constant darkness for 10 days posttreatment.

RESULTS

At ZT6, c-fos mRNA was significantly induced 120 min post-MDMA treatment but there were no significant changes in Per1 or Per2 mRNA expression. At ZT16, there were significant inductions of c-fos mRNA (30 and 60 min) and Per1 and Per2 mRNA (both 60 min) post-MDMA treatment. However, no differences in behavioral activity patterns were noted following MDMA treatment at ZT16.

CONCLUSIONS

These data provide evidence that MDMA has time of day dependent actions on SCN functioning, as evident from its induction of core clock genes that are important for generating and maintaining circadian rhythmicity.

Linking the pharmacological content of ecstasy tablets to the subjective experiences of drug users

RATIONALE

Most studies on the subjective effects of ecstasy are based on the assumption that the substance that was taken is 3,4-methylenedioxymethamphetamine (MDMA). However, many tablets sold as ecstasy contain other substances and MDMA in varying doses. So far, few attempts have been made to take this into account while assessing subjective effects.

OBJECTIVES

This study aims to link the pharmacological content of tablets sold as ecstasy to the subjective experiences reported by ecstasy users.

METHODS

Self-reported effects on ecstasy tablets were available from 5,786 drug users who handed in their tablets for chemical analysis at the Drug Information and Monitoring System (DIMS) in the Netherlands. Logistic regression was employed to link the pharmacological content of ecstasy tablets to the self-reported subjective effects and compare effects with MDMA to other substances present.

RESULTS

MDMA showed a strong association with desirable subjective effects, unparalleled by any other psychoactive substance. However, the association of MDMA was dose-dependent, with higher doses (>120 mg/tablet) likely to evoke more adverse effects. The novel psychostimulants mephedrone and p-fluoroamphetamine were considered relatively desirable, whereas meta-chlorophenylpiperazine (mCPP) and p-methoxymethamphetamine (PMMA) were strongly associated with adverse subjective effects. Also, 3,4-methylene-dioxyamphetamine (MDA) and benzylpiperazine (BZP) were not appreciated as replacement for MDMA.

CONCLUSION

Linking the pharmacological content of ecstasy sold on the street to subjective experiences contributes to a better understanding of the wide range of subjective effects ascribed to ecstasy and provides a strong rationale for the prolonged endurance of MDMA as the key ingredient of the ecstasy market.

Instability of the ecstasy market and a new kid on the block: mephedrone

Recently, several reports have indicated instability of the ecstasy market in the Netherlands and other EU countries. In the current study, we demonstrate this instability in the Netherlands, showing a decrease of ecstasy tablets containing 3,4-methylenedioxymetamphetamine (MDMA) by more than 50% in 2009. In addition, we describe a partial replacement of MDMA in tablets sold as ecstasy by a previously unseen substance, mephedrone (or 4-methylmethcathinone). Mephedrone was quantified and ecstasy tablets contained between 96 and 155 mg of this new compound. So far, no studies about mephedrone's effects have been published. For this study, we gathered information on the acute subjective effects of mephedrone from 70 regular ecstasy users. Overall, the majority of users considered the effects enjoyable. Mephedrone seemed to evoke effects similar to other amphetamine type psychostimulants, including MDMA. In contrast to MDMA, however, mephedrone induced strong feelings of craving in most users. If the unstable ecstasy market situation persists, the potential of mephedrone to substitute for MDMA might be substantial. Mephedrone, sold as ecstasy, is therefore likely to be a valid cause for health concern.

Ecstasy use and suicidal behavior among adolescents: findings from a national survey

The relationship between ecstasy use and suicidal behavior among adolescents in the United States was examined. Data from the adolescent subsample (ages 12-17, N = 19,301) of the 2000 National Household Survey on Drug Abuse were used in the analyses. Information on adolescent substance use, suicidal behaviors, and related sociodemographic, family, and individual factors was obtained in the survey. The rate of past year suicide attempt among adolescents with lifetime ecstasy use was almost double that of adolescents who had used other drugs only, and nine times that of adolescents with no history of illicit drug use. In multinomial logistic regression analyses controlling for related factors, the effect of ecstasy use remained significant. Adolescent ecstasy users may require enhanced suicide prevention and intervention efforts.

Procedural and declarative memory task performance, and the memory consolidation function of sleep, in recent and abstinent ecstasy/MDMA users

Ecstasy/MDMA use has been associated with various memory deficits. This study assessed declarative and procedural memory in ecstasy/MDMA users. Participants were tested in two sessions, 24 h apart, so that the memory consolidation function of sleep on both types of memory could also be assessed. Groups were: drug-naive controls (n = 24); recent ecstasy/MDMA users, who had taken ecstasy/MDMA 2-3 days before the first testing session (n = 25), and abstinent users, who had not taken ecstasy/MDMA for at least 8 days before testing (n = 17). Procedural memory did not differ between groups, but greater lifetime consumption of ecstasy was associated with poorer procedural memory. Recent ecstasy/MDMA users who had taken other drugs (mainly cannabis) 48-24 h before testing exhibited poorer declarative memory than controls, but recent users who had not taken other drugs in this 48-24-h period did not differ from controls. Greater lifetime consumption of ecstasy, and of cocaine, were associated with greater deficits in declarative memory. These results suggest that procedural, as well as declarative, memory deficits are associated with the extent of past ecstasy use. However, ecstasy/MDMA did not affect the memory consolidation function of sleep for either the declarative or the procedural memory task.

An investigation of the subacute effects of ecstasy on neuropsychological performance, sleep and mood in regular ecstasy users

The aim of this study was to differentiate the subacute from the chronic effects of ecstasy. Regular ecstasy users who subsequently chose to take ecstasy (experimental group: E, N = 16) were compared with regular ecstasy users who opted not to (control group: C, N = 16). Groups were assessed with neuropsychological and psychometric measures at drug-free baseline before ecstasy use and 1 and 4 days after use. Ecstasy users who consumed ecstasy (E) did not differ from those who did not (C) in relation to age, estimated IQ, personality or past substance use, including ecstasy. At baseline, E reported being more energetic, lively and cheerful whereas the day after ecstasy use they reported being more muddled, afraid, sad and dejected than C. However, this was not significant after controlling for sleep deprivation. Mood returned to baseline within 3 days and there were no group differences in Beck depression inventory scores at any of the three testing sessions. There were no subacute effects of ecstasy on working memory, story recall, impulsivity, or decision-making. However, at baseline and the day after use ecstasy users made poorer decisions, and were less sensitive to punishment, in the Somatic marker sensitivity test. These findings suggest that previous reports of marked subacute effects of ecstasy use may have been confounded by chronic polydrug use before use, co-substance use and sleep disturbances after use.

Test-re-test reliability of DSM-IV adopted criteria for 3,4-methylenedioxymethamphetamine (MDMA) abuse and dependence: a cross-national study

AIMS

This study evaluated the prevalence and reliability of DSM-IV adopted criteria for 3,4-methylenedioxymethamphetamine (MDMA) abuse and dependence with a purpose to determine whether it is best conceptualized within the category of hallucinogens, amphetamines or its own category.

DESIGN

Test-re-test study.

PARTICIPANTS

MDMA users (life-time use >5 times) were recruited in St Louis, Miami and Sydney (n=593). The median life-time MDMA consumption was 50 pills at the baseline.

MEASUREMENTS

The computerized Substance Abuse Module for Club Drug (CD-SAM) was used to assess MDMA abuse and dependence. The Discrepancy Interview Protocol (DIP) was used to determine the reasons for the discrepant responses between the two interviews. Reliability of diagnoses, individual diagnostic criteria and withdrawal symptoms was examined using the kappa coefficient (κ). findings for baseline data, 15% and 59% met MDMA abuse and dependence, respectively. Substantial test-re-test reliability of the diagnoses was observed consistently across cities (κ=0.69). 'Continued use despite knowledge of physical/psychological problems' (87%) and 'withdrawal' (68%) were the two most prevalent dependence criteria. 'Physically hazardous use' was the most prevalent abuse criterion. Six dependence criteria and all abuse criteria were reported reliably across cities (κ: 0.53-0.77). Seventeen of 19 withdrawal symptoms showed consistency in the reliability across cities. The most commonly reported reason for discrepant responses was 'interpretation of question changed'. Only a small proportion of the total discrepancies were attributed to lying or social desirability.

CONCLUSION

The adopted DSM-IV diagnostic classification for MDMA abuse and dependence was moderately reliable across cities. findings on MDMA withdrawal support the argument that MDMA should be separated from other hallucinogens in DSM.

Effects of priming injections of MDMA and cocaine on reinstatement of MDMA- and cocaine-seeking in rats

Exposure to self-administered drugs is sufficient to produce drug-seeking in animal models. In many cases priming injections of drugs that share discriminative stimulus properties with the self-administered drug also can lead to drug-seeking, suggesting that exposure might precipitate relapse. The present investigation examined the ability of MDMA or cocaine priming injections to reinstate extinguished drug-seeking in rats. Priming injections of cocaine (0-20.0 mg/kg) and MDMA (0.0-10.0 mg/kg) reinstated extinguished drug-taking for both the cocaine- and MDMA-trained rats. In a separate group of cocaine-trained rats that received repeated exposure to 10.0 mg/kg MDMA, the initial exposure to MDMA (10.0 mg/kg, i.p.) failed to reinstate extinguished responding but MDMA became an effective prime for reinstatement of extinguished cocaine-taking behavior with repeated exposure. Effects of MDMA in MDMA-trained rats was greater than the effect in cocaine-trained rats suggesting that extensive experience with MDMA self-administration might have sensitized rats to this effect. These findings show that extinguished MDMA self-administration, like self-administration of other drugs of abuse, can be reinstated by exposure to psychostimulants thereby precipitating relapse.

Reduced sensitivity to MDMA-induced facilitation of social behaviour in MDMA pre-exposed rats

The acute effects of the party drug 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy") in humans include feelings of love, closeness towards other people and an increased acceptance of others views and feelings. Some evidence suggests that regular MDMA users develop a subsensitivity to the positive effects of the drug and escalate their intake of the drug over time as a result. The current study investigated whether brief exposure to relatively high doses of MDMA in rats produces a subsequent attenuation in the ability of MDMA to enhance social interaction. Male Wistar rats were exposed to either MDMA (4 x 5 mg/kg over 4 h) or vehicle on two consecutive days. Twelve weeks later, MDMA pre-exposed rats displayed a significantly shorter period of time spent in social interaction than controls when tested in the drug-free state. MDMA pre-exposed rats also showed a blunted prosocial response to MDMA (2.5 mg/kg) relative to controls. This difference was overcome by increasing the MDMA dose to 5 mg/kg. The 5-HT(1A) agonist 8-OH-DPAT (250 microg/kg but not 125 microg/kg) increased social interaction and this effect did not differ in MDMA and vehicle pre-exposed rats. HPLC analysis showed a small but significant depletion of prefrontal 5-HT and 5-HIAA in MDMA pre-exposed rats. Prefrontal 5-HIAA concentrations were also reduced in the subset of vehicle and MDMA pre-exposed rats that received additional testing with MDMA. These results indicate that treatment with MDMA not only causes lasting reductions in social interaction in rats but causes an attenuation of the prosocial effects of subsequent MDMA administration. The lack of a differential response to 8-OH-DPAT agrees with other findings that the 5-HT(1A) receptor system remains functionally intact following MDMA pre-exposure and suggests that other neuroadaptations may underlie the lasting social deficits caused by MDMA.

Effect of illicit recreational drugs upon sleep: cocaine, ecstasy and marijuana

The illicit recreational drugs cocaine, ecstasy and marijuana have pronounced effects upon sleep. Administration of cocaine increases wakefulness and suppresses REM sleep. Acute cocaine withdrawal is often associated with sleep disturbances and unpleasant dreams. Studies have revealed that polysomnographically assessed sleep parameters deteriorate even further during sustained abstinence, although patients report that sleep quality remains unchanged or improves. This deterioration of objective sleep measures is associated with a worsening in sleep-related cognitive performance. Like cocaine, 3,4-methylenedioxymethamphetamine (MDMA; "ecstasy") is a substance with arousing properties. Heavy MDMA consumption is often associated with persistent sleep disturbances. Polysomnography (PSG) studies have demonstrated altered sleep architecture in abstinent heavy MDMA users. Smoked marijuana and oral Delta-9-tetrahydrocannabinol (THC) reduce REM sleep. Moreover, acute administration of cannabis appears to facilitate falling asleep and to increase Stage 4 sleep. Difficulty sleeping and strange dreams are among the most consistently reported symptoms of acute and subacute cannabis withdrawal. Longer sleep onset latency, reduced slow wave sleep and a REM rebound can be observed. Prospective studies are needed in order to verify whether sleep disturbances during cocaine and cannabis withdrawal predict treatment outcome.

Self reported sleep quality and cognitive performance in ecstasy users

OBJECTIVES

Research suggests that ecstasy users exhibit psychobiological changes relative to nonusers such as altered sleep patterns and cognitive deficits. In turn, it has been suggested that sleep quality may be a mediator of such cognitive deficits in ecstasy users. The present study sought to investigate this proposed relationship.

METHODS

Aspects of cognitive functioning in 104 ecstasy users and 103 nonusers obtained from our previous studies were reanalysed to explore the extent to which ecstasy-related group differences were attributable to differences in sleep quality. Cognitive function was assessed via the computation span test, consonant updating, paired associate learning, syllogistic reasoning and word fluency. Sleep quality was measured via the Epworth Sleepiness Scale (ESS), and the Karolinska Sleepiness Scale (KSS).

RESULTS

Ecstasy users performed worse than nonusers on all cognitive measures. While no differences were observed on the ESS, ecstasy users reported greater tiredness at the beginning of testing than nonusers. When the sleep variables were included as covariates, the effects of ecstasy on all cognitive measures remained significant.

CONCLUSIONS

The results of the present study suggest little evidence for the mediating effects of sleep on cognitive function in ecstasy users.