No difference in brain activation during cognitive performance between ecstasy (3,4-methylenedioxymethamphetamine) users and control subjects: a [H2(15)O]-positron emission tomography study

Mephedrone and MDMA: A comparative review

Mephedrone and MDMA are both constituents of party drugs, with mephedrone being relatively new compared to MDMA. This review compares current knowledge regarding the patterns of usage and neuropsychobiological effects of both mephedrone and MDMA. Both drugs share common psychoactive effects, the duration of which is significantly shorter with mephedrone use, attributing towards a pattern of binge use among users. Both drugs have also been associated with adverse health, psychiatric, and neurocognitive problems. Whilst there is extensive research into the psychobiological problems induced by MDMA, the evidence for mephedrone is comparatively limited. The adverse effect profile of mephedrone appears to be less severe than that of MDMA. Users often believe it to be safer, although both drugs have been associated with overdoses. The neurotoxic potential of mephedrone appears to be low, whereas MDMA can cause long-term damage to the serotonergic system, although this needs further investigation. The abuse liability of mephedrone is significantly greater than that of MDMA, raising concerns regarding the impact of lifetime usage on users. Given that mephedrone is relatively new, the effects of long-term exposure are yet to be documented. Future research focused on lifetime users may highlight more severe neuropsychobiological effects from the drug.

MDMA, serotonergic neurotoxicity, and the diverse functional deficits of recreational 'Ecstasy' users

Serotonergic neurotoxicity following MDMA is well-established in laboratory animals, and neuroimaging studies have found lower serotonin transporter (SERT) binding in abstinent Ecstasy/MDMA users. Serotonin is a modulator for many different psychobiological functions, and this review will summarize the evidence for equivalent functional deficits in recreational users. Declarative memory, prospective memory, and higher cognitive skills are often impaired. Neurocognitive deficits are associated with reduced SERT in the hippocampus, parietal cortex, and prefrontal cortex. EEG and ERP studies have shown localised reductions in brain activity during neurocognitive performance. Deficits in sleep, mood, vision, pain, psychomotor skill, tremor, neurohormonal activity, and psychiatric status, have also been demonstrated. The children of mothers who take Ecstasy/MDMA during pregnancy have developmental problems. These psychobiological deficits are wide-ranging, and occur in functions known to be modulated by serotonin. They are often related to lifetime dosage, with light users showing slight changes, and heavy users displaying more pronounced problems. In summary, abstinent Ecstasy/MDMA users can show deficits in a wide range of biobehavioral functions with a serotonergic component.

Sustaining attention to simple tasks: a meta-analytic review of the neural mechanisms of vigilant attention

Maintaining attention for more than a few seconds is essential for mastering everyday life. Yet, our ability to stay focused on a particular task is limited, resulting in well-known performance decrements with increasing time on task. Intriguingly, such decrements are even more likely if the task is cognitively simple and repetitive. The attentional function that enables our prolonged engagement in intellectually unchallenging, uninteresting activities has been termed vigilant attention. Here we synthesized what we have learned from functional neuroimaging about the mechanisms of this essential mental faculty. To this end, a quantitative meta-analysis of pertinent neuroimaging studies was performed, including supplementary analyses of moderating factors. Furthermore, we reviewed the available evidence on neural time-on-task effects, additionally considering information obtained from patients with focal brain damage. Integrating the results of both meta-analysis and review, we identified a set of mainly right-lateralized brain regions that may form the core network subserving vigilant attention in humans, including dorsomedial, mid- and ventrolateral prefrontal cortex, anterior insula, parietal areas (intraparietal sulcus, temporoparietal junction), and subcortical structures (cerebellar vermis, thalamus, putamen, midbrain). We discuss the potential functional roles of different nodes of this network as well as implications of our findings for a theoretical account of vigilant attention. It is conjectured that sustaining attention is a multicomponent, nonunitary mental faculty, involving a mixture of (a) sustained/recurrent processes subserving task-set/arousal maintenance and (b) transient processes subserving the target-driven reorienting of attention. Finally, limitations of previous studies are considered and suggestions for future research are provided.

Modelling the adverse effects associated with ecstasy use

AIMS

Ecstasy, the street name for 3,4-meththylenedioxymethamphetamine, has been associated with a range of psychiatric symptoms and impaired psychological health in both problem and recreational users. The purpose of the present paper is to determine how these impairments are related to the history of polydrug use, and the conditions under which individuals ingest ecstasy.

DESIGN

Associations between the variables of interest were investigated utilizing negative binomial regression.

SETTING

Liverpool and Preston in the North West of England.

PARTICIPANTS

A convenience sample of 159 recreational ecstasy/polydrug users (80 males, 79 females). The sample was composed primarily of undergraduates.

MEASUREMENTS

The dependent variable was the number of reported ecstasy-related adverse effects. Independent variables included quantitative aspects of ecstasy and other drug use, and the various beliefs and behaviours associated with ecstasy use.

FINDINGS

The number of adverse effects was associated positively with life-time exposure to ecstasy and negatively with period of abstinence from the drug. Adverse effects were more common among those who consumed ecstasy and alcohol concurrently, but were unrelated to other aspects of polydrug use. They were unaffected by whether the user took precautions when using the drug, and only weakly related to prior beliefs concerning the effects of ecstasy.

CONCLUSIONS

Greater life-time exposure to ecstasy and consuming the drug concurrently with alcohol increase the likelihood of experiencing adverse effects, including paranoia, poor general health, irritability, confusion and moodiness. Adverse effects decrease with the period of abstinence from the drug.

Modifiable risk factors of ecstasy use: risk perception, current dependence, perceived control, and depression

Risk perception, perceived behavioral control of obtaining ecstasy (PBC-obtaining), current ecstasy dependence, and recent depression have been associated with past ecstasy use, however, their utility in predicting ecstasy use has not been demonstrated. This study aimed to determine whether these four modifiable risk factors could predict ecstasy use after controlling for socio-demographic covariates and recent polydrug use. Data from 601 ecstasy users in the National Institute on Drug Abuse-funded TriCity Study of Club Drug Use, Abuse and Dependence were analyzed using multivariate logistic regression. Participants were interviewed twice within a 2-week period using standardized instruments. Thirteen percent (n = 80) of the participants reported using ecstasy between the two interviews. Low risk perception, high PBC-obtaining (an estimated ecstasy procurement time < 24h), and current ecstasy dependence were statistically associated with ecstasy use between the two interviews. Recent depression was not a significant predictor. Despite not being a target predictor, recent polydrug use was also statistically associated with ecstasy use. The present findings may inform the development of interventions targeting ecstasy users.

Neurotoxicity of drugs of abuse--the case of methylenedioxyamphetamines (MDMA, ecstasy), and amphetamines

Ecstasy (MDMA, 3,4-methylendioxymethamphetamine) and the stimulants methamphetamine (METH, speed) and amphetamine are popular drugs among young people, particularly in the dance scene. When given in high doses both MDMA and the stimulant amphetamines are clearly neurotoxic in laboratory animals. MDMA causes selective and persistent lesions of central serotonergic nerve terminals, whereas amphetamines damage both the serotonergic and dopaminergic systems. In recent years, the question of ecstasy-induced neurotoxicity and possible functional sequelae has been addressed in several studies in drug users. Despite large methodological problems, the bulk of evidence suggests residual alterations of serotonergic transmission in MDMA users, although at least partial recovery may occur after long-term abstinence. However, functional sequelae may persist even after longer periods of abstinence. To date, the most consistent findings associate subtle cognitive impairments with ecstasy use, particularly with memory. In contrast, studies on possible long-term neurotoxic effects of stimulant use have been relatively scarce. Preliminary evidence suggests that alterations of the dopaminergic system may persist even after years of abstinence from METH, and may be associated with deficits in motor and cognitive performance. In this paper, we will review the literature focusing on human studies.

Reward-related decision-making deficits and elevated impulsivity among MDMA and other drug users

BACKGROUND

The recreational drug, 3,4-methylenedioxymethamphetamine (MDMA; 'Ecstasy'), is a synthetic amphetamine derivative and a serotonin neurotoxin. MDMA use is associated with cognitive dysfunction and impulsivity, but since polydrug abuse is common among users it is difficult to attribute these problems specifically to MDMA. Moreover, few studies have examined reward-related cognitive processes. Our aim was to examine reward-related decision-making and impulsivity among MDMA users while controlling for polydrug use via appropriate comparison groups.

METHODS

We examined decision-making [Iowa Gambling Task, IGT; Bechara, A., Damasio, A.R., Damasio, H., Anderson, S.W., 1994. Insensitivity to future consequences following damage to human prefrontal cortex. Cognition 50, 7-15], self-reported impulsivity (Multidimensional Personality Questionnaire-Brief Form [constraint subscale]; Barratt Impulsiveness Scale; Zuckerman Sensation Seeking Scale), and drug use among 22 abstinent MDMA users, 30 other drug users, and 29 healthy non-drug controls.

RESULTS

MDMA and other drug users showed comparable patterns of decision-making and impulsivity. However, both drug groups demonstrated poorer IGT performance and elevated self-reported impulsivity relative to controls. Poorer decision-making was related to heavier drug use in the past year, heavier weekly alcohol use, and meeting lifetime substance use disorder (SUD) criteria for more drug classes. Elevated impulsivity was associated with heavier drug use, heavier weekly alcohol use, more lifetime SUDs, and higher self-reported depression levels.

CONCLUSIONS

These findings contradict the idea that MDMA is specifically associated with deficient decision-making. Drug users, in general, may be at risk for decision-making deficits and elevated impulsivity. Such behaviors may represent trait factors that lead to the initiation of drug and alcohol use, and/or they may represent behavior patterns that are exacerbated by extensive use.

Major depression: the relative contribution of gender, MDMA, and cannabis use

Previous research has suggested that 3,4-methylenedioxymethamphetamine (MDMA; ecstasy) users have elevated depressive symptomatology, although it is not clear whether this is due to MDMA or other drug use. This study aimed to investigate the contributions of MDMA and cannabis use to Major Depressive Disorder in MDMA users. A total of 226 MDMA users were studied. Participants (65% male) reported an average number of 35.8 uses of MDMA (SD = 45.6, range = 2-400). Participants were administered a Structured Clinical Interview for DSM-IV. Twenty-six individuals (11.5%) met lifetime criteria for Major Depressive Disorder. High rates of lifetime Cannabis Abuse (30.1%) and Cannabis Dependence (12.4%) were reported. No association was found between number of uses of MDMA and Major Depressive Disorder. Those with lifetime major depression were found, however, to have higher rates of lifetime cannabis use disorder (adjusted OR = 2.40). A logistic regression indicated that lifetime cannabis use disorder, but not MDMA use, was significantly associated with lifetime Major Depressive Disorder. Stratified analyses suggested that for males, neither drug use variable was associated with major depression. For females, a lifetime cannabis use disorder (adjusted OR = 4.99), but not MDMA use, was associated with lifetime Major Depressive Disorder. Results of this study suggest that although MDMA use was not found to be significantly associated with major depression for either gender, a lifetime cannabis use disorder was significantly associated with lifetime major depression for female, but not male, users of MDMA.

The dark side of ecstasy: neuropsychiatric symptoms after exposure to 3,4-methylenedioxymethamphetamine

3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) is a known neurotoxin in animals. This review discusses the history, pattern of use, pharmacology, acute and long-term effects of MDMA. Emphasis is given to the concern that MDMA may induce long-term cognitive and psychiatric effects. MDMA is an illegal substance, and investigations of the effects of exposure in human beings have limitations and weaknesses. There are numerous studies suggesting a correlation between MDMA exposure and psychopathology, and that the psychotropic effects may be long-lasting or permanent. However, it is not possible to conclude that there is a causal relationship between exposure and the increased psychopathology observed in MDMA users. Longitudinal studies are needed to assess whether MDMA causes persistent cognitive impairment and/or psychiatric symptoms in human beings.

Family, peer and individual factors related to methylenedioxymethamphetamine use in Taiwanese adolescents

Examination of the correlates of methylenedioxymethamphetamine (MDMA) use is crucial for the development and implementation of effective prevention programs for adolescents. The aim of the present study was therefore to identify the family, peer and individual factors that were related to MDMA use in Taiwanese adolescents. Two hundred adolescents who used MDMA and 200 who did not use MDMA were recruited into the study. The family, peer and individual factors related to MDMA use were examined using chi(2) automatic interaction detection (CHAID) analysis. The results indicated that the adolescents who had more friends involved with substance use, disruptive family and attitude favoring MDMA use were more likely to use MDMA. Multiple factors of family, peer and individuals were related to MDMA use among Taiwanese adolescents. This knowledge may be helpful when designing and implementing preventive intervention programs.

Is recreational ecstasy (MDMA) use associated with higher levels of depressive symptoms?

Due to potential serotonergic deficits, 3,4-methylenedioxymethamphetamine (MDMA or Ecstasy) may cause long-term mood disruptions in recreational Ecstasy users. The purpose of this review is to evaluate the evidence for a relationship between recreational Ecstasy use and higher levels of depressive symptoms. Eleven out of 22 studies initially have reported significantly higher depression scores in Ecstasy users in comparison to control participants. However, only three studies ultimately have revealed significantly higher depression scores in comparison to cannabis or polydrug controls. Furthermore, most studies have suffered from methodological weaknesses, and the levels of depressive symptoms that have been found in Ecstasy users have not been shown to be much higher than those found in normative groups. The evidence for an association specifically between Ecstasy use and higher levels of depressive symptoms is currently unconvincing, but the frequent concomitant use of Ecstasy and other illicit drugs has been shown to be associated with higher levels of depressive symptoms. Possible causes include polydrug use in general, MDMA-induced serotonergic deficits, individual effects of illicit drugs besides Ecstasy, combined effects of MDMA and other illicit drugs, and preexisting differences in the levels of depressive symptoms in Ecstasy users.

Serotonergic vulnerability and depression: assumptions, experimental evidence and implications

In recent years, the term serotonergic vulnerability (SV) has been used in scientific literature, but so far it has not been explicitly defined. This review article attempts to elucidate the SV concept. SV can be defined as increased sensitivity to natural or experimental alterations of the serotonergic (5-HTergic) system. Several factors that may disrupt the 5-HTergic system and hence contribute to SV are discussed, including genetic factors, female gender, personality characteristics, several types of stress and drug use. It is explained that SV can be demonstrated by means of manipulations of the 5-HTergic system, such as 5-HT challenges or acute tryptophan depletion (ATD). Results of 5-HT challenge studies and ATD studies are discussed in terms of their implications for the concept of SV. A model is proposed in which a combination of various factors that may compromise 5-HT functioning in one person can result in depression or other 5-HT-related pathology. By manipulating 5-HT levels, in particular with ATD, vulnerable subjects may be identified before pathology initiates, providing the opportunity to take preventive action. Although it is not likely that this model applies to all cases of depression, or is able to identify all vulnerable subjects, the strength of the model is that it may enable identification of vulnerable subjects before the 5-HT related pathology occurs.

Neuroimaging research in human MDMA users: a review

RATIONALE

Determining whether, under what circumstances, and to what extent 3,4-methylenedioxymethamphetamine (MDMA) exposure produces chronic changes in human brain function is a critical public health issue. MDMA is a widely used recreational drug commonly sold as "Ecstasy". Because findings from the animal literature have indicated that specific dosage regimens of MDMA can produce long-lasting alterations in serotonergic function, existing studies of MDMA effects in humans have examined brain serotonin (5-HT) transporters (5-HTT) and receptors or have examined brain structures or functions potentially affected by MDMA.

OBJECTIVES

The objectives of this review are to provide a background for interpreting human MDMA neuroimaging research, to examine existing neuroimaging data regarding the rationale for and limitations to human MDMA research, and to provide suggestions for improving the design and interpretation of future neuroimaging approaches.

RESULTS

Of the existing neuroimaging studies in human MDMA users, few experimental designs have been replicated across different research groups. Only investigations employing nuclear imaging methods to assay brain 5-HTT levels have been replicated across methods and research laboratories. These studies have found reduced levels of the 5-HTT in recently abstinent MDMA users with some evidence for normalization of 5-HTT levels with prolonged abstinence. However, the sensitivity of these methods is unknown.

CONCLUSIONS

The current state of neuroimaging in human MDMA users does not permit conclusions regarding the long-term effects of MDMA exposure. Future study designs might benefit from improved sample homogeneity, increased length of MDMA abstinence, longitudinal study design, test-retest measures, serotonergic specificity, and multimodal approaches.

MDMA use is associated with increased spatial BOLD fMRI visual cortex activation in human MDMA users

Previous animal studies have demonstrated that 3,4-methylenedioxymethamphetamine (MDMA) exposure causes serotonin axotomy that is greatest in occipital cortex (including primary visual cortex) where serotonergic axons innervate neurons and blood vessels. Human MDMA users have altered serotonergic function and reduced gray matter density in occipital cortex. The fMRI BOLD method is potentially sensitive to both the neuronal and vascular consequences of MDMA-induced serotonin toxicity. To test the hypothesis that MDMA users have altered visual system function, we used the fMRI BOLD technique to assay visual cortical activation after photic stimulation in a group of adult MDMA users. Because MDMA users worldwide are polydrug users and therefore difficult to match to comparison groups in terms of polydrug exposure, we conducted a primary within-group analysis examining the correlation between lifetime episodes of MDMA exposure and measures of visual cortical activation. The within-group correlational analysis in the MDMA user group revealed that the degree of prior MDMA exposure was significantly positively correlated with the number of activated pixels for photic stimulation (r=0.582, p=0.007). A secondary between-group comparison of MDMA users with non-MDMA users found overall greater levels of polydrug exposure in the MDMA user cohort but no significant differences in visual cortical activation measures between the two groups. Additional research is needed to clarify the origin and significance of the current findings.

Problematic versus non-problematic ecstasy/MDMA use: the influence of drug usage patterns and pre-existing psychiatric factors

Recreational ecstasy (3,4-methylenedioxymethamphetamine; MDMA) use has been increasingly associated with a number of psychiatric symptoms and psychological problems. However, previous studies assessing possible psychopathological effects have not identified whether users consider their ecstasy use "problematic" or not. In addition, research has generally failed to address the potential role of premorbid psychiatric status. This study aimed to assess whether premorbid psychiatric history and/or patterns of ecstasy use would be associated with the degree of self-reported problems attributable to ecstasy. Problematic ecstasy users (n = 53) who had reported problems attributable to their ecstasy use were compared with non-problematic ecstasy users (n = 62), polydrug controls (n = 62) and illegal drug-naive controls (n = 111) on a recreational drug use questionnaire; a questionnaire, which ascertained personal and family psychiatric histories, and the Brief Symptom Inventory (BSI). Problematic ecstasy users exhibited significantly higher scores on a number of dimensions of the BSI compared to illegal drug-naive and/or polydrug controls. Problematic ecstasy users also exhibited significantly elevated scores on somatization, depression, anxiety and negative psychobiology compared to non-problematic ecstasy users. BSI scores for the non-problematic ecstasy users did not differ from polydrug or illegal drug-naive controls. Problematic ecstasy users reported significantly higher levels of ecstasy use, including lifetime consumption, average dosage and binge consumption compared to non-problematic ecstasy users. Additionally, a greater number of problematic ecstasy users reported personal and family psychiatric histories compared to controls and non-problematic ecstasy users. This study demonstrates two distinct ecstasy using groups: non-problematic ecstasy users who are not showing signs of psychopathology and problematic ecstasy users who are showing evidence of a range of symptoms. This data therefore partially supports the link between ecstasy dosage and negative psychological sequelae, but highlights the importance of the need to consider ecstasy-related attributions, pre-existing mental health status and vulnerability.

Mood, cognition and serotonin transporter availability in current and former ecstasy (MDMA) users: the longitudinal perspective

Although 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) is a known serotonergic neurotoxin in different animal species, there is to date no conclusive evidence of its neurotoxicity in humans. MDMA use was associated with impairments of psychological well-being, verbal memory and altered serotonergic functioning in a number of cross-sectional studies. Due to inherent methodological limitations, such as the notorious polydrug use of ecstasy users and lack of control of possible pre-existing differences between ecstasy users and control participants, researchers have called for well-controlled, prospective longitudinal studies to shed more light on the issue of MDMA neurotoxicity to the human brain. This longitudinal study investigated whether mood, cognition and central serotonin transporters (SERT) would deteriorate with continued MDMA use and whether or not they would recover over increasing periods of MDMA abstinence. In a repeated-measures design, 11 current and ten ex-ecstasy users, and 11 polydrug (but not MDMA) and 15 drug-naive controls participated three times within approximately two years. Both ecstasy user groups reported a polydrug use pattern besides heavy ecstasy use. Subjective reports of ecstasy use or abstinence were verified by toxicological analyses. On each trial, the participants underwent a cognitive test battery and filled in the Symptom Check List. The availability of central SERT was assessed with positron emission tomography using the McN5652 ligand for all groups at t1, and only for the ecstasy user groups on follow-ups. The factor Group yielded significant results in the SCL-90 scales Global Severity Index, Anxiety, Obsessive/compulsive and Interpersonal sensitivity, with the ex-ecstasy users reporting the highest symptom scores. There were significant Group effects in all measures of verbal memory, with the lowest performance in the group of ex-ecstasy users. The repeated-measures analyses yielded no significant Group x Time interactions in any SCL-90 scales or measures of memory performance, with the exception of AVLT 1 immediate recall. Thus the ex-ecstasy users' psychopathological symptoms and memory performance failed to improve, and the current ecstasy users' failed to deteriorate, over time relative to the other groups. While there was a significant effect of Group in all brain regions examined (except the control region white matter), the current users' SERT availability seems to have recovered in the mesencephalon, as indicated by a significant Group x Time interaction. Reduced SERT availability might be a transient effect of heavy ecstasy use, since it partially recovered as the current users reduced their MDMA use. However, this measure may not necessarily be a valid indicator of the number or integrity of serotonergic neurons. Ex-ecstasy users' verbal memory showed no sign of improvement even after over 2.5 years of abstinence and thus may represent persistent functional consequences of MDMA neurotoxicity. However, alternative causes such as pre-existing group differences cannot be completely ruled out in spite of the longitudinal design.

Ecstasy use and self-reported depression, impulsivity, and sensation seeking: a prospective cohort study

Although there are indications that ecstasy users have higher levels of depression, impulsivity, and sensation seeking, it is unknown whether these are consequences of ecstasy use or predisposing factors for starting ecstasy use. We prospectively assessed the predictive value of depression, impulsivity, and sensation seeking on future first time ecstasy use. We also assessed whether depression, impulsivity, and sensation seeking had changed after first ecstasy use. Depression, impulsivity, and sensation seeking were assessed using self-report questionnaires in 188 ecstasy-naive volunteers with high probability for future ecstasy use. After a mean follow-up of 17 months, measurements were repeated in 59 incident ecstasy users (mean 6.0 tablets) and 61 matched persistent ecstasy-naive volunteers. Only experience seeking (subscale of the sensation seeking scale) predicted future ecstasy use (OR -- 1.05, 95% CI 1.00 to 1.10), but after adjustment for potential confounders this was not significant anymore. At follow-up, significant effects of ecstasy use on the general and the disinhibition subscale of the sensation seeking scale were observed (after adjustment for potential confounders: regression coefficient B 0.51, 95% CI 0.20 to 0.83 and B -- 3.25, 95% CI 1.74 to 4.76, respectively). These data indicate that depression, impulsivity, and sensation seeking do not predict first time ecstasy use in a population of young adults with the intention to start using ecstasy and that low level ecstasy use does not seem to cause depression or impulsivity. However, low level ecstasy use may increase (certain aspects of) sensation seeking.

MDMA in humans: factors which affect the neuropsychobiological profiles of recreational ecstasy users, the integrative role of bioenergetic stress

Many recreational ecstasy/MDMA users display neuropsychobiological deficits, whereas others remain problem free. This review will investigate some of the drug and non-drug factors which influence the occurrence of these deficits. Acute and chronic MDMA usage are both important. Intensive use within a session is often associated with more problems. In term of lifetime usage, novice users generally remain unimpaired, whereas most heavy users report memory or other psychobiological problems which they attribute to ecstasy. These complaints are confirmed by objective deficits in working memory, attention, frontal-executive, and episodic memory tasks. Psychobiological deficits include disturbed sleep, sexual dysfunction, reduced immuno-competence, and increased oxidative stress. Further MDMA-related factors which may contribute to these changes, include acute and chronic tolerance, and drug dependence. Around 90ñ95% of ecstasy/MDMA users also take cannabis, and this can independently contribute to the adverse neuropsychobiological pro.les; although in some situations the acute co-use of these two drugs may be interactive rather than additive, since cannabis has relaxant and hypothermic properties. Alcohol, nicotine, amphetamine, and other drugs, can also affect the psychobiological pro.les of ecstasy polydrug users in complex ways. Pure MDMA users are rare but they have been shown to display significant neurocognitive deficits. Psychiatric aspects are debated in the context of the diathesis-stress model. Here the stressor of ecstasy polydrug drug use, interacts with various predisposition factors (genetic, neurochemical, personality), to determine the psychiatric outcome. Recreational MDMA is typically taken in hot and crowded dances/raves. Prolonged dancing, feeling hot, and raised body temperature, can also be associated with more psychobiological problems. This is consistent with the animal literature, where high ambient temperature and other metabolic stimulants boost the acute effects of MDMA, and cause greater serotonergic neurotoxicity. In conclusion, the neuropsychobiological effects of MDMA are modulated by a wide range of drug and non-drug factors. These multiple influences are integrated within a bioenergetic stress model, where factors which heighten acute metabolic distress lead to more neuropsychobiological problems.

Neurotoxicity of methylenedioxyamphetamines (MDMA; ecstasy) in humans: how strong is the evidence for persistent brain damage?

BACKGROUND

The popular dance drug ecstasy (3,4-methylenedioxymethamphetamine: MDMA and some analogues) causes selective and persistent neurotoxic damage of central serotonergic neurones in laboratory animals. Serotonin plays a role in numerous functional systems in the central nervous system (CNS). Consequently, various abnormalities including psychiatric, vegetative, neuroendocrine and cognitive disorders could be expected in humans following MDMA-induced neurotoxic brain damage.

AIMS

In recent years, the question of ecstasy-induced neurotoxicity and possible functional sequelae has been addressed in several studies with drug users. The aim of this paper was to review this literature and weigh the strength of the evidence for persistent brain damage in ecstasy users.

METHODS

We used Medline to view all available publications on 'ecstasy' or 'MDMA'. All available studies dealing with ecstasy users entered this analysis.

FINDINGS AND CONCLUSIONS

Despite large methodological problems the bulk of evidence suggests residual alterations of serotonergic transmission in MDMA users, although at least partial restitution may occur after long-term abstinence. However, functional sequelae may persist even after longer periods of abstinence. To date, the most consistent findings associate subtle cognitive, particularly memory, impairments with heavy ecstasy use. However, the evidence cannot be considered definite and the issues of possible pre-existing traits or the effects of polydrug use are not resolved.

RECOMMENDATIONS

Questions about the neurotoxic effects of ecstasy on the brain remain highly topical in light of its popularity among young people. More longitudinal and prospective studies are clearly needed in order to obtain a better understanding of the possible long-term sequelae of ecstasy use in humans.

Cognitive function and mood in MDMA/THC users, THC users and non-drug using controls

Repeated ecstasy (MDMA) use is reported to impair cognition and cause increased feelings of depression and anxiety. Yet, many relevant studies have failed to control for use of drugs other than MDMA, especially marijuana (THC). To address these confounding effects we compared behavioural performance of 11 MDMA/THC users, 15 THC users and 15 non-drug users matched for age and intellect. We tested the hypothesis that reported feelings of depression and anxiety and cognitive impairment (memory, executive function and decision making) are more severe in MDMA/THC users than in THC users. MDMA/THC users reported more intense feelings of depression and anxiety than THC users and non-drug users. Memory function was impaired in both groups of drug users. MDMA/THC users showed slower psychomotor speed and less mental flexibility than non-drug users. THC users exhibited less mental flexibility and performed worse on the decision making task compared to non-drug users but these functions were similar to those in MDMA/THC users. It was concluded that MDMA use is associated with increased feelings of depression and anxiety compared to THC users and non-drug users. THC users were impaired in some cognitive abilities to the same degree as MDMA/THC users, suggesting that some cognitive impairment attributed to MDMA is more likely due to concurrent THC use.

Event-related potentials (ERPs) in ecstasy (MDMA) users during a visual oddball task

Ecstasy is the common name for a drug mainly containing a substance identified as 3,4-methylenedioxymethamphetamine (MDMA). It has become popular with participants in "raves", because it enhances energy, endurance and sexual arousal, together with the widespread belief that MDMA is a safe drug [Byard, R.W., Gilbert, J., James, R., Lokan, R.J., 1998. Amphetamine derivative fatalities in South Australia. Is "ecstasy" the culprit? Am. J. Forensic Med. Pathol. 19, 261-265]. However, it is suggested that this drug causes a neurotoxicity to the serotonergic system that could lead to permanent physical and cognitive problems. In order to investigate this issue, and during an ERP recording with 32 channels, we used a visual oddball design, in which subjects (14 MDMA abusers and 14 paired normal controls) saw frequent stimuli (neutral faces) while they had to detect as quickly as possible rare stimuli with happy or fearful expression. At a behavioral level, MDMA users imply longer latencies than normal controls to detect rare stimuli. At the neurophysiological level, ERP data suggest as main result that the N200 component, which is involved in attention orienting associated to the detection of stimulus novelty (e.g. [Campanella, S., Gaspard, C., Debatisse, D., Bruyer, R., Crommelinck, M., Guerit, J.M., 2002. Discrimination of emotional facial expression in a visual oddball task: an ERP study. Biol. Psychol. 59, 171-186]), shows shorter latencies for fearful rare stimuli (as compared to happy ones), but only for normal controls. This absence of delay was interpreted as an attentional deficit due to MDMA consumption.

Ecstasy (MDMA) exposure and neuropsychological functioning: a polydrug perspective

Ecstasy (MDMA) is a popular drug that can act as a selective serotonin neurotoxin in several species. The goal of the present study was to examine the relationship between ecstasy exposure and cognitive functioning after controlling for other drug use and demographic variables. Furthermore, we assessed whether gender was a moderator of the relationship between cognitive functioning and ecstasy use. Data were collected from 31 men and 34 women with a wide range of ecstasy use (17 marijuana users with no ecstasy use and 48 ecstasy users ranging from low to heavy use). Participants were interviewed and administered a battery of neuropsychological tests. The primary finding was that ecstasy exposure was significantly related to poorer verbal learning and memory ability in a dose-dependent manner, while no such relationship was observed between ecstasy exposure and executive functioning or attentional ability. Gender was found to significantly moderate the relationship between ecstasy consumption and design fluency. These results suggest primary memory dysfunction among abstinent recreational ecstasy users. This finding is consistent with reports of hippocampal vulnerability, particularly among heavy users.

Mental disorders in current and former heavy ecstasy (MDMA) users

BACKGROUND

Ecstasy use has often been found to be associated with psychopathology, yet this research has so far been based largely on subjective symptom ratings.

AIMS

To investigate whether ecstasy users suffered from long-term psychopathological consequences.

MEASUREMENTS

We compared the prevalence of Diagnostic and Statistical Manual version IV (DSM-IV) mental disorders in 30 current and 29 former ecstasy users, 29 polydrug and 30 drug-naive controls. Groups were approximately matched by age, gender and level of education. The current ecstasy users reported a life-time dose of an average of 821 and the former ecstasy users of 768 ecstasy tablets.

FINDINGS

Ecstasy users did not significantly differ from controls in the prevalence of mental disorders, except those related to substance use. Substance-induced affective, anxiety and cognitive disorders occurred more frequently among ecstasy users than polydrug controls. The life-time prevalence of ecstasy dependence amounted to 73% in the ecstasy user groups. More than half of the former ecstasy users and nearly half of the current ecstasy users met the criteria of substance-induced cognitive disorders at the time of testing. Logistic regression analyses showed the estimated life-time doses of ecstasy to be predictive of cognitive disorders, both current and life-time.

CONCLUSIONS

The motivation for ecstasy use is not likely to be self-medication of pre-existing depressive or anxiety disorders as these did not occur more frequently in the ecstasy users than in control groups or in the general population. Cognitive disorders still present after over 5 months of ecstasy abstinence may well be functional consequences of serotonergic neurotoxicity of 3,4-methylenedioxymethamphetamine (MDMA).

The P3 in 'ecstasy' polydrug users during response inhibition and execution

Substance abuse and associated externalizing disorders are characterized by behavioural disinhibition and low impulse control, with reduced neural inhibition postulated to be the common underlying brain mechanism. The P3 component of event-related potentials (ERPs) is a widely used neurophysiological measure thought to reflect inhibitory brain processes, but as yet has not been assessed in ecstasy users. We recorded ERPs evoked by a Continuous Performance Test (CPT) in 16 current ecstasy polydrug users and 17 controls. The CPT included conditions where a prepared motor response had to be executed (Go) or inhibited (NoGo). Both controls and ecstasy users showed normal, robust patterns of P3 anteriorization and delay in the NoGo compared to the Go condition. Ecstasy users had lower P3 amplitudes at midline electrodes and a less anterior location of NoGo P3 peaks. These effects became weaker after statistically controlling for age, educational level and lifetime cannabis use. While lower P3 amplitudes are consistent with higher levels of neural disinhibition in ecstasy polydrug users, the normal switch pattern between response execution and inhibition, and the less anterior location of the NoGo P3, do not indicate disturbed inhibitory brain mechanisms.

Long-term effects of MDMA (Ecstasy) on the human central nervous system revealed by visual evoked potentials

Several studies indicate long-term cognitive impairment of MDMA (ecstasy) users. In the present study we attempted to establish whether electrophysiological correlates of low-level cognitive processes present a long-term alteration, dependent on the level of use of ecstasy. We addressed this issue by investigating amplitude and latency of VEPs related to a very simple discrimination task involving sustained attention (arousal). Eight heavy-MDMA users, eight moderate-MDMA users and 18 drug-free control subjects were asked to discriminate whether the digit at the centre of the screen was 1 or 2. None of the subjects (except one) had used MDMA in the 6 months previous testing. We measured psychophysical performance and EEG, recorded in Oz and Fz during task execution. The heavy-MDMA users made significantly more errors than the other two groups (p < .05). Moreover, they presented reduced amplitude but not latency of VEPs in both Oz and Fz. The effect in Oz is present in P200 (for heavy users only, p < .05) and in P300 components (for both MDMA groups; heavy users: p < .001, moderate users: p < .0.5). In Fz, the amplitude effect is present in N250 (for heavy users only, p < .05) and in P300 components (for both MDMA groups; heavy users: p < .05, moderate users: p < .05). The three groups do not differ in early components, reflecting low-level processing. These results provide evidence of long-term electrophysiological abnormality displayed by ecstasy users and agree with the suggestion that even typical recreational doses of ecstasy are sufficient to cause long-term altered cortical activity in humans.

Self-reported depressive symptomatology in community samples of polysubstance misusers who report Ecstasy use: a meta-analysis

National drugs information strategies convey the message that use of Ecstasy is associated with an increase in both the incidence and severity of major depressive disorder. However, very little primary research supports this. Unlike apparent deficits in higher cognitive functions, most published studies have found no difference in self-reported depressive symptomatology between Ecstasy users and controls. To investigate this further, we conducted a meta-analysis of studies investigating depressive symptomatology in recreational users of Ecstasy. According to selection criteria, we identified 25 relevant studies. A statistically significant effect size (ES) of 0.31 (95% confidence interval 0.17-0.37, p < 0.001) was calculated. Significance remained after examining the small number of studies that controlled for cannabis use (n = 9, p < 0.001) but, in general, drug histories were poorly reported. There was an association between ES and lifetime Ecstasy exposure (p < 0.001), but not for other use parameters or abstention (p > 0.05). These data indicate that there is an association between Ecstasy use and depressive symptomatology, but this is small and unlikely to be clinically relevant. In addition, the self-report scales used may be heavily confounded by the somatic effects of substance misuse. Public health strategies derived from psychopharmacological investigations should acknowledge the potential negative effects of substance misuse but qualify the difficulties in interpreting research studies.

Functional MRI study of working memory in MDMA users

RATIONALE

Methylene-dioxymethamphetamine (MDMA) is known to cause degeneration of serotonin nerve terminals after acute doses in animals. Similarly, behavioral studies in human MDMA users regularly find abnormalities in memory, mood, and impulse control. However, studies of brain function using brain imaging in MDMA users have been less consistent.

OBJECTIVES

The purpose of this study was to determine, using functional magnetic resonance imaging (fMRI), whether individuals with a self-reported history of MDMA use would differ from non-MDMA using controls on activation while performing a working memory task.

METHODS

Fifteen MDMA using subjects and 19 non-MDMA using controls underwent fMRI scanning while performing the immediate and delayed memory task (IMT/DMT). The study was based on a block design in which the delayed memory task (DMT) alternated with the immediate memory task (IMT), which served as a control condition. FMRI scans were acquired on a 1.5 T scanner, using a gradient echo echoplanar pulse sequence.

RESULTS

Random effects SPM99 analysis showed significantly greater activation (whole volume corrected cluster P<0.05) during the DMT relative to the IMT in the MDMA subjects compared with the control subjects in the medial superior frontal gyrus, in the thalamus extending into putamen, and in the hippocampus.

CONCLUSIONS

Although these effects could be due to other drugs used by MDMA users, these results are consistent with behavioral problems that are associated with MDMA use, and with animal studies on the effects of MDMA on brain function.

Neural mechanisms of working memory in ecstasy (MDMA) users who continue or discontinue ecstasy and amphetamine use: evidence from an 18-month longitudinal functional magnetic resonance imaging study

BACKGROUND

Working memory processing in ecstasy (3,4-methylenedioxymethamphetamine) users is associated with neural alterations as measured by functional magnetic resonance imaging. Here, we examined whether cortical activation patterns change after prolonged periods of continued use or abstinence from ecstasy and amphetamine.

METHODS

We used an n-back task and functional magnetic resonance imaging in 17 ecstasy users at baseline (t(1)) and after 18 months (t(2)). Based on the reported drug use at t(2) we separated subjects with continued ecstasy and amphetamine use from subjects reporting abstinence during the follow-up period (n = 9 and n = 8, respectively).

RESULTS

At baseline both groups had similar task performance and similar cortical activation patterns. Task performance remained unchanged in both groups. Furthermore, there were no detectable functional magnetic resonance imaging signal changes from t(1) to t(2) in the follow-up abstinent group. However, the continuing users showed a dose-dependent increased parietal activation for the 2-back task after the follow-up period.

CONCLUSIONS

Our data suggest that ecstasy use, particularly in high doses, is associated with greater parietal activation during working memory performance. An altered activation pattern might appear before changes in cognitive performance become apparent and, hence, may reflect an early stage of neuronal injury from the neurotoxic drug ecstasy.

Relationship between ecstasy use and depression: a study controlling for poly-drug use

RATIONALE

3,4-Methylenedioxymethamphetamine (MDMA or "ecstasy") causes serotonin neuron damage in laboratory animals. The serotonin system is known to be important in the regulation of mood. Previous research has shown that MDMA users score higher on self-report ratings of depression than controls. However, MDMA users commonly take other illicit substances and many studies do not fully control for poly-drug use.

OBJECTIVES

The aim of this study was to examine the relationship between MDMA use and affective disturbance, while fully controlling for poly-drug use.

METHODS

Participants were 30 current MDMA users, 30 poly-drug controls who had never used MDMA, 30 drug-naïve controls with no history of illicit drug use and 20 ex-MDMA users. The current MDMA users and poly-drug controls were well matched on all indices of non-MDMA drug use. All participants were administered the Beck Depression Inventory (BDI) and the Affective Go/No-go task, which has been shown to be sensitive to depression.

RESULTS

The current and ex-MDMA users scored significantly higher on the BDI than the drug-naive controls, but were not significantly different from the poly-drug controls. There were no differences between the groups in terms of affective bias scores on the Affective Go/No-go task.

CONCLUSIONS

Increased scores on self-report depression scales in MDMA users are not entirely attributable to MDMA use. MDMA users do not show the same attentional bias towards negatively toned material as depressed patients.

Ecstasy intoxication: the toxicological basis for treatment

Youngsters are increasingly using 3,4 methylenedioxymethamphetamine, known as ecstasy, because it is wrongly believed that it does not induce harm. However, there are many reports of adverse effects, including acute intoxication, abuse potential, and possible neurotoxic effects. Therefore, health care providers need to promptly recognize the symptoms of systemic intoxication in order to initiate early treatment. The drug is used by the oral route for long hours during crowded dance parties. Acutely, ecstasy increases the release of serotonin and decreases its reuptake, leading to hypertension, hyperthermia, trismus, and vomiting. There is debate on whether recreational doses of ecstasy cause permanent damage to human serotonergic neurons. Ecstasy users showed a high risk of developing psychopathological disturbances. The prolonged use of ecstasy might induce dependence, characterized by tolerance and hangover. Acute ecstasy intoxication needs emergency-type treatment to avoid the dose-dependent increase in adverse reactions and in severity of complications. There are no specific antidotes to be used during acute intoxication. Supportive measures and medical treatment for each one of the complications should be implemented, keeping in mind that symptoms originate mainly from the central nervous system and the cardiovascular system.

Neural correlates of working memory in pure and polyvalent ecstasy (MDMA) users

Poor cognitive performance in ecstasy (3,4-methylenedioxymethamphetamine; MDMA) users has been related to the well-recognized neurotoxic effects of the drug upon central serotonergic and possibly also dopaminergic systems. However, concomitant use of other drugs has been a critical confound in most investigations. In this study we used an n-back task and fMRI to investigate working memory performance and related cerebral activation in eight, currently abstinent pure MDMA users and two matched groups of polyvalent MDMA users and non-users. Pure MDMA users presented lower activations than controls and/or polyvalent users, most notably in inferior temporal regions, the angular gyrus and the striate cortex, whereas polyvalent users did not differ from controls. Our results suggest that altered brain activation patterns during cognitive processing in ecstasy users may be mainly associated with prior MDMA use. Concomitant use of other drugs may modify this effect.

Cerebral activation in abstinent ecstasy (MDMA) users during a working memory task: a functional magnetic resonance imaging (fMRI) study

The popular recreational drug ecstasy (3,4-methylenedioxymethamphetamine=MDMA and related congeners) is neurotoxic upon central serotonergic systems in animal studies. So far, the most convincing evidence for neurotoxicity-related functional deficits in humans derives from neurocognitive studies demonstrating dose-related long-term learning and memory problems in ecstasy users. In our study we used functional magnetic resonance imaging (fMRI) and a working memory task to investigate cerebral activation in eleven heavy, but currently abstinent MDMA users and two equally sized groups of moderate users and non-users. There were no significant group differences in working memory performance and no differences in cortical activation patterns for a conservative level of significance. However, for a more liberal statistical criterion, both user groups showed stronger activations than controls in right parietal cortex. Furthermore, heavy users had a weaker blood oxygenation level-dependent (BOLD) response than moderate users and controls in frontal and temporal areas. Our results may indicate subtle altered brain functioning associated with prior MDMA use, although alternative interpretations of these group differences must be considered.

MDMA ('ecstasy') and other 'club drugs'. The new epidemic

Unfortunately, perceptions that the club drugs can be safe endure. Some groups, such as the Multidisciplinary Association for Psychedelic Study, continue to lobby for the legalization of MDMA for research purposes [76]. DanceSafe is an organization that seeks to educate the "nonaddicted" user to decrease the risks [82]. The DanceSafe Web site offers tips on the safe use of MDMA, such as attention to hydration status and ambient temperature. It also offers free testing of tablets submitted by mail and sells home testing kits to determine the content of pills sold as "ecstasy." Although much remains unknown about the long-term consequences of MDMA and the club drugs, there are clearly enough short-term dangers to prompt more aggressive education and surveillance for its use. Scare tactics and exaggerations often are ignored [53], while Web sites full of anecdotal or incomplete information may lead the unaware user to increased use [113]. Organizations such as DanceSafe imply that proper education decreases addiction and that only uneducated users or addicts suffer the life-altering consequences of drug use. The fallacy in the mission of educating "nonaddicted" users is evident. Peer-based education, with a focus on both he short-term dangers and long-term consequences, may be a more effective approach [9]. Both new and established drugs of abuse continue to plague teens and young adults. Pediatric, family practice, and Med-Peds physicians, and pediatric pharmacologists need to remain vigilant about patterns and trends of drug abuse. MDMA and the other "club drugs" are not benign. Their effects target the brain, alter neurochemistry, and possibly cause irreversible structural damage. What may seem like a harmless drug in a weekend dance club has the potential for major public health problems in years to come [109]. Effective education and timely intervention may prevent these addictive drugs from becoming a way of life, a lifestyle that may have a literal "dead end."

Investigating the potential neurotoxicity of Ecstasy (MDMA): an imaging approach

Human users of 3,4-methylenedioxymethamphetamine (MDMA, 'Ecstasy') users may be at risk of developing MDMA-induced neuronal injury. Previously, no methods were available for directly evaluating the neurotoxic effects of MDMA in the living human brain. However, development of in vivo neuroimaging tools has begun to provide insights into the effects of MDMA in the human brain. In this review, contributions of brain imaging studies on the potential neurotoxic effects of MDMA and functional consequences are highlighted. An overview is given of PET, SPECT and MR spectroscopy studies, most of which show evidence of neuronal injury in MDMA users. Different neuroimaging tools are discussed that have investigated potential functional consequences of MDMA-induced 5-HT neurotoxic lesions. Finally, the contribution of brain imaging in future studies is discussed, emphasising the crucial role it will play in our understanding of MDMA's short- and long-term effects in the human brain. Copyright 2001 John Wiley & Sons, Ltd.

Which neuroreceptors mediate the subjective effects of MDMA in humans? A summary of mechanistic studies

In preclinical studies, 3,4-methylenedioxymethamphetamine (MDMA, 'Ecstasy') has been shown to release serotonin (5-HT), dopamine and norepinephrine. However, the role of these neurotransmitters and their corresponding receptor sites in mediating the subjective effects of MDMA has not yet been studied in humans. Therefore, we investigated the effects of three different neuroreceptor pretreatments on the subjective, cardiovascular and adverse effects of MDMA (1.5 mg/kg orally) in 44 healthy human volunteers. Pretreatments were: the selective serotonin reuptake inhibitor citalopram (40 mg intravenously) in 16 subjects, the 5-HT(2) antagonist ketanserin (50 mg orally) in 14 subjects, and the D(2) antagonist haloperidol (1.4 mg intravenously) in 14 subjects. Each of these studies used a double-blind placebo-controlled within-subject design and all subjects were examined under placebo, pretreatment, MDMA and pretreatment plus MDMA conditions. Citalopram markedly reduced most of the subjective effects of MDMA, including positive mood, increased extraversion and self-confidence. Cardiovascular and adverse effects of MDMA were also attenuated by citalopram. Haloperidol selectively reduced MDMA-induced positive mood but had no effect on other subjective effects of MDMA or the cardiovascular or adverse responses to MDMA. Ketanserin selectively reduced MDMA-induced perceptual changes and emotional excitation. These results indicate that the overall psychological effects of MDMA largely depend on carrier-mediated 5-HT release, while the more stimulant-like euphoric mood effects of MDMA appear to relate, at least in part, to dopamine D(2) receptor stimulation. The mild hallucinogen-like perceptual effects of MDMA appear to be due to serotonergic 5-HT(2) receptor stimulation. Copyright 2001 John Wiley & Sons, Ltd.