Reasoning deficits in ecstasy (MDMA) polydrug users

Of mice and men on MDMA: A translational comparison of the neuropsychobiological effects of 3,4-methylenedioxymethamphetamine ('Ecstasy')

MDMA (3,4-methylendioxymethamphetamine), also known as Ecstasy, is a stimulant drug recreationally used by young adults usually in dance clubs and raves. Acute MDMA administration increases serotonin, dopamine and noradrenaline by reversing the action of the monoamine transporters. In this work, we review the studies carried out over the last 30 years on the neuropsychobiological effects of MDMA in humans and mice and summarise the current knowledge. The two species differ with respect to the neurochemical consequences of chronic MDMA, since it preferentially induces serotonergic dysfunction in humans and dopaminergic neurotoxicity in mice. However, MDMA alters brain structure and function and induces hormonal, psychomotor, neurocognitive, psychosocial and psychiatric outcomes in both species, as well as physically damaging and teratogen effects. Pharmacological and genetic studies in mice have increased our knowledge of the neurochemical substrate of the multiple effects of MDMA. Future work in this area may contribute to developing pharmacological treatments for MDMA-related disorders.

Mood Fluctuation and Psychobiological Instability: The Same Core Functions Are Disrupted by Novel Psychoactive Substances and Established Recreational Drugs

Many novel psychoactive substances (NPS) have entered the recreational drug scene in recent years, yet the problems they cause are similar to those found with established drugs. This article will debate the psychobiological effects of these newer and more traditional substances. It will show how they disrupt the same core psychobiological functions, so damaging well-being in similar ways. Every psychoactive drug causes mood states to fluctuate. Users feel better on-drug, then feel worse off-drug. The strength of these mood fluctuations is closely related to their addiction potential. Cyclical changes can occur with many other core psychobiological functions, such as information processing and psychomotor speed. Hence the list of drug-related impairments can include: homeostatic imbalance, HPA axis disruption, increased stress, altered sleep patterns, neurohormonal changes, modified brain rhythms, neurocognitive impairments, and greater psychiatric vulnerability. Similar patterns of deficit are found with older drugs such as cocaine, nicotine and cannabis, and newer substances such as 3,4-methylenedioxymethamphetamine (MDMA), mephedrone and spice. All psychoactive drugs damage human well-being through similar basic neuropsychobiological mechanisms.

Recreational 3,4-methylenedioxymethamphetamine or 'ecstasy': Current perspective and future research prospects

AIMS

The purpose of this article is to debate current understandings about the psychobiological effects of recreational 3,4-methylenedioxymethamphetamine (MDMA or 'ecstasy'), and recommend theoretically-driven topics for future research.

METHODS

Recent empirical findings, especially those from novel topic areas were reviewed. Potential causes for the high variance often found in group findings were also examined.

RESULTS AND CONCLUSIONS

The first empirical reports into psychobiological and psychiatric aspects from the early 1990s concluded that regular users demonstrated some selective psychobiological deficits, for instance worse declarative memory, or heightened depression. More recent research has covered a far wider range of psychobiological functions, and deficits have emerged in aspects of vision, higher cognitive skill, neurohormonal functioning, and foetal developmental outcomes. However, variance levels are often high, indicating that while some recreational users develop problems, others are less affected. Potential reasons for this high variance are debated. An explanatory model based on multi-factorial causation is then proposed.

FUTURE DIRECTIONS

A number of theoretically driven research topics are suggested, in order to empirically investigate the potential causes for these diverse psychobiological deficits. Future neuroimaging studies should study the practical implications of any serotonergic and/or neurohormonal changes, using a wide range of functional measures.

Recreational stimulants, herbal, and spice cannabis: The core psychobiological processes that underlie their damaging effects

AIMS

Recreational drugs are taken for their positive mood effects, yet their regular usage damages well-being. The psychobiological mechanisms underlying these damaging effects will be debated.

METHODS

The empirical literature on recreational cannabinoids and stimulant drugs is reviewed. A theoretical explanation for how they cause similar types of damage is outlined.

RESULTS

All psychoactive drugs cause moods and psychological states to fluctuate. The acute mood gains underlie their recreational usage, while the mood deficits on withdrawal explain their addictiveness. Cyclical mood changes are found with every central nervous system stimulant and also occur with cannabis. These mood state changes provide a surface index for more profound psychobiological fluctuations. Homeostatic balance is altered, with repetitive disturbances of the hypothalamic-pituitary-adrenal axis, and disrupted cortisol-neurohormonal secretions. Hence, these drugs cause increased stress, disturbed sleep, neurocognitive impairments, altered brain activity, and psychiatric vulnerability. Equivalent deficits occur with novel psychoactive stimulants such as mephedrone and artificial "spice" cannabinoids. These psychobiological fluctuations underlie drug dependency and make cessation difficult. Psychobiological stability and homeostatic balance are optimally restored by quitting psychoactive drugs.

CONCLUSIONS

Recreational stimulants such as cocaine or MDMA (3.4-methylenedioxymethamphetamine) and sedative drugs such as cannabis damage human homeostasis and well-being through similar core psychobiological mechanisms.

Why all stimulant drugs are damaging to recreational users: an empirical overview and psychobiological explanation

AIMS

Stimulant drugs such as nicotine and Ecstasy/3, 4-methylenedioxymethamphetamine (MDMA) are taken for positive reasons, yet their regular use leads to deficits rather than gains. This article outlines the psychobiological rationale for this paradox.

METHODS

The empirical literature on nicotine, cocaine, amphetamine, Ecstasy/MDMA, and mephedrone are reviewed. A theoretical explanation for why they are problematic to humans is then described.

RESULTS

The acute effects of central nervous system (CNS) stimulants are typically positive, with greater alertness and emotional intensity. However, in the post-drug recovery period, the opposite feelings develop, with lethargy and low moods. All recreational stimulants cause mood fluctuation, although it is most pronounced in drugs with rapid onset and comedown (e.g. nicotine and cocaine), explaining why they are the most addictive. Parallel fluctuations occur across many psychological and neurocognitive functions, with users suffering various off-drug deficits. CNS stimulants also affect the hypothalamic-pituitary-adrenal axis, impairing sleep, disrupting homeostasis, and exacerbating psychiatric distress. Neuroimaging studies reveal altered brain activity patterns in regular users. These problems are related to lifetime usage but commence in novice users.

CONCLUSIONS

Repetitive CNS stimulation is potentially damaging to the organism, both acutely and chronically. The review describes the various psychobiological systems through which recreational stimulant drugs impair human well-being.

Reasoning deficits among illicit drug users are associated with aspects of cannabis use

Deficits in deductive reasoning have been observed among ecstasy/polydrug users. The present study seeks to investigate dose-related effects of specific drugs and whether these vary with the cognitive demands of the task. One hundred and five participants (mean age 21.33, SD 3.14; 77 females, 28 males) attempted to generate solutions for eight one-model syllogisms and one syllogism for which there was no valid conclusion. All of the one-model syllogisms generated at least one valid conclusion and six generated two valid conclusions. In these six cases, one of the conclusions was classified as common and the other as non-common. The number of valid common inferences was negatively associated with the aspects of short-term cannabis use and with measures of IQ. The outcomes observed were more than simple post-intoxication effects since cannabis use in the 10 days immediately before testing was unrelated to reasoning performance. Following adjustment for multiple comparisons, the number of non-common valid inferences was not significantly associated with any of the drug-use measures. Recent cannabis use appears to impair the processes associated with generating valid common inferences while not affecting the production of non-common inferences. It is possible, therefore, that the two types of inference may recruit different executive resources, which may differ in their susceptibility to cannabis-related effects.

Human psychobiology of MDMA or 'Ecstasy': an overview of 25 years of empirical research

AIMS

This paper aimed to review how scientific knowledge about the human psychobiology of MDMA has developed over time.

METHODS

In this paper, the empirical findings from earlier and later studies will be reviewed.

RESULTS

When MDMA was a 'novel psychoactive substance', it was not seen as a drug of abuse, as it displayed loss of efficacy. However, recreational users display a unique pattern of increasing doses, deteriorating cost-benefit ratios, and voluntary cessation. MDMA increases body temperature and thermal stress, with cortisol levels increased by 800% in dance clubbers. It can be extremely euphoric, although negative moods are also intensified. MDMA causes apoptosis (programmed cell death) and has been investigated for cancer therapy because of its anti-lymphoma properties. Recreational users show deficits in retrospective memory, prospective memory, higher cognition, problem solving, and social intelligence. Basic cognitive skills remain intact. Neuroimaging studies show reduced serotonin transporter levels across the cerebral cortex, which are associated with neurocognitive impairments. Deficits also occur in sleep architecture, sleep apnoea, complex vision, pain, neurohormones, and psychiatric status. Ecstasy/MDMA use during pregnancy leads to psychomotor impairments in the children.

CONCLUSIONS

The damaging effects of Ecstasy/MDMA are far more widespread than was realized a few years ago, with new neuropsychobiological deficits still emerging.

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.

Neurobehavioral outcomes of infants exposed to MDMA (Ecstasy) and other recreational drugs during pregnancy

3,4-methylenedioxymethamphetamine (MDMA) or "Ecstasy" is one of the most widely used illicit recreational drugs among young adults. MDMA is an indirect monoaminergic agonist and reuptake inhibitor that primarily affects the serotonin system. Preclinical studies in animals have found prenatal exposure related to neonatal tremors and long-term learning and memory impairments. To date, there are no prospective studies of the sequelae of prenatal exposure to MDMA in humans, despite concerns about its potential for harmful effects to the fetus. The present study is the first to prospectively identify MDMA-using women during pregnancy and to document patterns and correlates of use with neonatal and early infancy outcomes of offspring. All mothers and infants were prospectively recruited through the Case Western Reserve University (CWRU) and University of East London (UEL) Drugs and Infancy Study (DAISY) that focused on recreational drug use in pregnant women. Women were interviewed about substance use prior to and during pregnancy and infants were seen at 1 and 4 months using standardized, normative assessments of neonatal behavior, and cognitive and motor development, including the NICU Network Neurobehavioral Scale (NNNS), the Bayley Mental and Motor Development Scales (MDI, PDI), and the Alberta Infant Motor Scales (AIMS). The sample was primarily middle class with some university education and in stable partner relationships. The majority of women recruited had taken a number of illicit drugs prior to or during pregnancy. Group differences between those polydrug using women who had specifically used MDMA during pregnancy (n=28) and those who had not (n=68) were assessed using chi-square and t-tests. MDMA and other drug effects were assessed through multiple regression analyses controlling for confounding variables. Women who used MDMA during pregnancy had fewer prior births and more negative sequelae associated with their drug use, including more health, work, and social problems. MDMA exposed infants differed in sex ratio (more male births) and had poorer motor quality and lower milestone attainment at 4 months, with a dose-response relationship to amount of MDMA exposure. These findings suggest risk to the developing infant related to MDMA exposure and warrant continued follow-up to determine whether early motor delays persist or resolve.

Visuospatial working memory impairment in current and previous ecstasy/polydrug users

OBJECTIVE

Previous research suggests that ecstasy users are impaired in processing visuospatial information. However, for the most part, the deficits observed appear to involve the recall and recognition of complex visual and geometric patterns. The present research sought to determine whether ecstasy use was associated with deficits in serial spatial recall and visuospatial working memory (VSWM).

METHODS

Thirty-eight current ecstasy/polydrug users, 16 previous ecstasy/polydrug users and 52 non ecstasy users completed serial simple spatial recall and VSWM tasks.

RESULTS

Both the current and previous users of ecstasy exhibited deficits on the VSWM task. Following controls for group differences in aspects of cannabis and cocaine use, the overall group effect fell to just below statistical significance. However, the difference contrast comparing users with nonusers continued to demonstrate a statistically significant ecstasy-related VSWM deficit.

CONCLUSIONS

Ecstasy users were impaired in processing visuospatial information especially under conditions of high processing demand. The results are consistent with ecstasy-related impairment either in the short-term posterior parietal and occipital area store or the dorsolateral prefrontal cortex processes, which augment it under conditions of higher processing demands. Further research is needed to pinpoint the actual source of the ecstasy/polydrug-related VSWM deficits that have been observed here and elsewhere.

Everyday and prospective memory deficits in ecstasy/polydrug users

The impact of ecstasy/polydrug use on real-world memory (i.e. everyday memory, cognitive failures and prospective memory [PM]) was investigated in a sample of 42 ecstasy/polydrug users and 31 non-ecstasy users. Laboratory-based PM tasks were administered along with self-reported measures of PM to test whether any ecstasy/polydrug-related impairment on the different aspects of PM was present. Self-reported measures of everyday memory and cognitive failures were also administered. Ecstasy/polydrug associated deficits were observed on both laboratory and self-reported measures of PM and everyday memory. The present study extends previous research by demonstrating that deficits in PM are real and cannot be simply attributed to self-misperceptions. The deficits observed reflect some general capacity underpinning both time- and event-based PM contexts and are not task specific. Among this group of ecstasy/polydrug users recreational use of cocaine was also prominently associated with PM deficits. Further research might explore the differential effects of individual illicit drugs on real-world memory.

Is emotional intelligence impaired in ecstasy-polydrug users?

Previous findings report use of the drug ecstasy (MDMA) to be associated with lower emotional intelligence (EI), and compromised functioning in brain areas responsible for emotion. This study explored the relationship between ecstasy use, EI, mood and parenting styles. Questionnaire measures of drug use, lifestyle, parenting style and EI were obtained, with separate IQ measures for fluid intelligence (Ravens matrices) and pre-morbid intelligence [National Adult Reading Test (NART)]. Current mood measures were obtained from an adjective checklist. The sample comprised 78 ecstasy/polydrug users, 38 cannabis only users and 34 non-drug users. Drug use was categorised at three levels (non-user, cannabis-only user and ecstasy-polydrug user). Factorial ANOVA using drug use as an independent variable showed no significant group effects in EI. EI showed significant correlations with current mood that were positive for arousal and negative for both anxiety and depression. EI was also significantly and positively correlated with the perceived degree of parental control. Regression analyses showed that these relationships remained significant after controlling for differences in IQ, age, gender, and ecstasy use. Adverse mood effects specifically associated with ecstasy use were significantly related to lower EI, and were independent of IQ, age and gender. Higher EI was significantly associated with ecstasy-related precautions used when taking this drug. Contrary to earlier findings, ecstasy-polydrug users did not differ from non-users on EI. However, self-reported ecstasy-related mood disturbances were related to lower EI, with the compromising of orbitofrontal cortical functioning being possible here.

Cortisol and 3,4-methylenedioxymethamphetamine: neurohormonal aspects of bioenergetic stress in ecstasy users

AIMS

3,4-Methylenedioxymethamphetamine (MDMA) can affect both neurotransmitter and neurohormonal activity. This review will debate the role of the metabolic activation hormone cortisol for the psychobiological effects of ecstasy/MDMA.

METHODS

The empirical literature on cortisol release following acute MDMA administration and cortisol functioning in drug-free recreational ecstasy/MDMA users will be reviewed. This will be followed by an overview of cortisol as a bioenergetic stress neurohormone, and a debate on how it could be modulating the acute and chronic psychobiological effects of MDMA.

RESULTS

Cortisol release is increased by stimulatory factors, including physical activity, thermal stress and stimulant drugs. In laboratory studies MDMA leads to an acute cortisol increase of around 150% in sedentary humans. In MDMA-using dance clubbers, the cortisol levels are increased by around 800%, possibly due to the combined factors of stimulant drug, physical exertion and psychosocial stimulation. Regular ecstasy/MDMA users also demonstrate changes in baseline cortisol levels and cortisol reactivity, with compromised hypothalamic-pituitary-adrenal activity. Nonpharmacological research has shown how cortisol is important for psychological aspects such as memory, cognition, sleep, impulsivity, depression and neuronal damage. These same functions are often impaired in recreational ecstasy/MDMA users, and cortisol may be an important modulatory co-factor.

CONCLUSIONS

The energizing hormone cortisol is involved in the psychobiology of MDMA, probably via its effects on energy metabolism. Acute cortisol release may potentiate the stimulating effects of MDMA in dance clubbers. Chronically, cortisol may contribute to the variance in functional and structural consequences of repeated ecstasy usage.

Auditory event-related potentials (P3) and cognitive performance in recreational ecstasy polydrug users: evidence from a 12-month longitudinal study

RATIONALE

There is important preclinical evidence of the long-lasting neurotoxic and selective effects of ecstasy (MDMA) on serotonin systems in nonhuman primates. In humans, long-term recreational use of ecstasy has been mainly associated with memory impairment.

OBJECTIVE

The first aim of our study was to evaluate the cognitive and electrophysiological long-term alterations associated with lifetime ecstasy use within a sample of ecstasy polydrug users along a 1-year follow-up. Our second aim was to explore the relationship between specific cognitive functions and P300 (P3) event-related potentials (ERPs) in ecstasy users.

MATERIALS AND METHODS

We conducted auditory P3 latency and amplitude and administered a battery of cognitive tests to three groups of subjects: 14 current ecstasy polydrug users, 13 current cannabis users, and 22 controls free of illicit drugs in two evaluations during 1 year.

RESULTS

We found significant differences between ecstasy users and controls on cognitive measures of word fluency, processing speed, and memory recognition after 1-year follow-up. We found no significant differences between ecstasy and cannabis users or cannabis users and controls on cognitive tests. Lifetime ecstasy use was associated with poorer memory recognition. No group differences were shown on P3 latency or amplitude. Significant correlations emerged between P3 latency and cannabis lifetime use (higher cannabis use was related to faster latency, showing a paradoxical effect) but not with ecstasy exposure.

CONCLUSIONS

Our findings provide evidence of mild long-term cognitive deficits among ecstasy polydrug users. Both ecstasy use and the dynamic interaction between ecstasy and cannabis effects may account for these deficits. No significant P3 alterations were found in ecstasy users.

Cognitive performance in recreational ecstasy polydrug users: a two-year follow-up study

There is important preclinical evidence of long lasting neurotoxic and selective effects of ecstasy MDMA on serotonin systems in non-human primates. In humans long-term recreational use of ecstasy has been mainly associated with learning and memory impairments. The aim of the present study was to investigate the neuropsychological profile associated with ecstasy use within recreational polydrug users, and describe the cognitive changes related to maintained or variable ecstasy use along a two years period. We administered cognitive measures of attention, executive functions, memory and learning to three groups of participants: 37 current polydrug users with regular consumption of ecstasy and cannabis, 23 current cannabis users and 34 non-users free of illicit drugs. Four cognitive assessments were conducted during two years. At baseline, ecstasy polydrug users showed significantly poorer performance than cannabis users and non-drug using controls in a measure of semantic word fluency. When ecstasy users were classified according to lifetime use of ecstasy, the more severe users (more than 100 tablets) showed additional deficits on episodic memory. After two years ecstasy users showed persistent deficits on verbal fluency, working memory and processing speed. These findings should be interpreted with caution, since the possibility of premorbid group differences cannot be entirely excluded. Our findings support that ecstasy use, or ecstasy/cannabis synergic effects, are responsible for the sub-clinical deficits observed in ecstasy polydrug users, and provides additional evidence for long-term cognitive impairment owing to ecstasy consumption in the context of polydrug use.

"At least one" problem with "some" formal reasoning paradigms

In formal reasoning, the quantifier "some" means "at least one and possibly all." In contrast, reasoners often pragmatically interpret "some" to mean "some, but not all" on both immediate-inference and Euler circle tasks. It is still unclear whether pragmatic interpretations can explain the high rates of errors normally observed on syllogistic reasoning tasks. To address this issue, we presented participants (reasoners) in the present experiments either standard quantifiers or clarified quantifiers designed to precisely articulate the quantifiers' logical interpretations. In Experiment 1, reasoners made significantly more logical responses and significantly fewer pragmatic responses on an immediate-inference task when presented with logically clarified as opposed to standard quantifiers. In Experiment 2, this finding was extended to a variant of the immediate-inference task in which reasoners were asked to deduce what followed from premises they were to assume to be false. In Experiment 3, we used a syllogistic reasoning task and observed that logically clarified premises reduced pragmatic and increased logical responses relative to standard ones, providing strong evidence that pragmatic responses can explain some aspects of the errors made in the syllogistic reasoning task. These findings suggest that standard quantifiers should be replaced with logically clarified quantifiers in teaching and in future research.

Dance clubbing on MDMA and during abstinence from Ecstasy/MDMA: prospective neuroendocrine and psychobiological changes

BACKGROUND/AIMS

The present study is the first to prospectively compare a group of recreational Ecstasy users when dance clubbing on 3,4-methylenedioxymethamphetamine (MDMA) and when clubbing during abstinence from Ecstasy/MDMA.

METHODS

Twelve normal healthy volunteers (mean age = 23.2 years) were assessed at a Saturday night dance club under self-administered MDMA. On the other weekend they went to the same dance club without taking MDMA (order counterbalanced). Both conditions involved 5 test sessions conducted at similar times: pre-drug baseline, 1 h post-drug clubbing, 2.5 h post-drug clubbing, and 2 and 4 days later. The assessments included body and ambient temperature, physical activity (pedometer), as well as self-ratings for mood state, physical activity, thermal comfort and thirst. Saliva samples were analyzed for MDMA, cortisol and testosterone.

RESULTS

The cortisol levels increased significantly by 800% when dance clubbing on MDMA, while testosterone increased significantly by 75%; neither neuroendocrine measure was altered during abstinence. Saliva analyses confirmed the presence of MDMA when dancing on Ecstasy and its absence when dancing off Ecstasy. The pedometer values and self-rated levels of dancing were similar at both weekends. Hot and cold flushes and feeling hot increased significantly under MDMA. The mean body temperature did not change significantly, although there was a borderline trend for increased values after MDMA. Feelings of happiness and excitement increased under MDMA, although they were not significantly greater than when clubbing during abstinence.

CONCLUSIONS

Neurohormonal release may be an important part of the acute MDMA experience. The large cortisol increase provides further data on the bioenergetic stress model of recreational Ecstasy/MDMA.

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.

Neurocognitive function in current and ex-users of ecstasy in comparison to both matched polydrug-using controls and drug-naïve controls

RATIONALE

Despite years of research and much controversy surrounding the effects of ecstasy use, findings are equivocal. Attempting to reduce methodological problems, such as concurrent use of other recreational drugs, could lead to a clearer picture of the effects of ecstasy use on cognitive function.

OBJECTIVES

The aim of this study is to investigate the effects of both prolonged abstention from ecstasy use and current use on cognitive function while controlling for the regular use of other recreational drugs used by ecstasy users (alcohol, cannabis, cocaine, amphetamines and lysergic acid diethylamide).

MATERIALS AND METHODS

A range of cognitive functions (including working memory, episodic memory, verbal learning and executive functions) was assessed in 109 participants: 25 current ecstasy users, 28 ex-ecstasy users (abstinent for at least 1 year), 29 polydrug-using controls (matched to both ecstasy-using groups for the use of other recreational drugs) and 27 drug-naïve controls.

RESULTS

There was an overall tendency for impaired verbal learning and memory in both current ecstasy users and polydrug controls. There was also evidence of reduced response inhibition in the current ecstasy users and polydrug controls, which appeared to be related to recency of drug use. However, the majority of tests showed no group differences.

CONCLUSIONS

The results suggest that recreational drug use in general, rather than ecstasy use per se, can lead to subtle cognitive impairments and that recent drug use appears to impact strongest on cognitive performance. This study highlights the importance of controlling for the use of all recreational drugs and, in particular, recent drug use when investigating 'effects of ecstasy' on cognitive function.

Information processing speed in ecstasy (MDMA) users

Previous research draws parallels between ecstasy-related and age-related deficits in cognitive functioning. Age-related impairments in working memory have been attributed to a slow down in information processing speed. The present study compared 29 current ecstasy users, 10 previous users and 46 non-users on two tests measuring information processing speed and a computation span task measuring working memory. Results showed that ecstasy users performed worse than non-ecstasy users in the letter comparison task although the overall difference was not significant (p=0.089). Results from the pattern recognition task showed that current ecstasy users produced significantly more errors than the other two groups (p<0.01). When results were combined for both the letter and pattern tasks, once again current ecstasy users produced significantly more errors than non-ecstasy users (p<0.01). Working memory deficits obtained were statistically significant with both ecstasy using groups performing significantly worse than non-users on the computation span measure (p<0.01). Moreover, ANCOVA with measures of processing speed as covariates failed to eliminate the group difference in computation span (p<0.01). Therefore, it is likely the mechanism responsible for impairments in the computation span measure is not the same as that in elderly adults where processing speed generally removes most of the age-related variance. Also of relevance is the fact that the ecstasy users reported here had used a range of other drugs making it difficult to unambiguously attribute the results obtained to ecstasy use.

The effects of concurrent cannabis use among ecstasy users: neuroprotective or neurotoxic?

The research evidence regarding the potential effects of ecstasy suggests that it may be neurotoxic and that its use is associated with cognitive impairment. In recent years evidence has emerged suggesting that cannabinoids, the active ingredients in cannabis, can be neuroprotective under certain conditions. Given that many ecstasy users also consume cannabis at the same time, the possibility emerges that these individuals might be less susceptible to ecstasy-related impairment. The present paper reanalyses the data from a number of previous studies, contrasting the performance of those individuals who generally consume cannabis and ecstasy at the same time with those who generally consume ecstasy on its own. The two ecstasy-using groups are compared with non-ecstasy users on a range of measures including processing speed, random letter generation, verbal and visuo-spatial working memory span, reasoning and associative learning. The two ecstasy user groups did not differ significantly from each other on any of the measures. Both user groups were significantly worse than non-ecstasy users on measures of associative learning, verbal and visuo-spatial working memory and reasoning. The results suggest that consuming cannabis at the same time as ecstasy does not reduce the likelihood of cognitive impairment.

Dancing hot on Ecstasy: physical activity and thermal comfort ratings are associated with the memory and other psychobiological problems reported by recreational MDMA users

BACKGROUND

Non-drug factors such as ambient temperature can heighten the adverse effects of MDMA (3,4-methylendioxymethamphetamine) in animals. We assessed whether dancing and feeling hot on Ecstasy would be associated with more psychobiological problems in recreational users.

METHODS

In an internet study, 206 unpaid participants (modal age 16-24) reported that they had used recreational Ecstasy/MDMA. They completed a drug use questionnaire, the Prospective Memory Questionnaire (PMQ), questions about dancing and feeling hot when on Ecstasy, and psychobiological problems afterwards.

RESULTS

Those who danced 'all the time' when on Ecstasy, reported significantly more PMQ memory problems than the less intensive dancers. Prolonged dancing was also associated with more complaints of depression, memory problems, concentration and organizational difficulties afterwards. Feeling hot when on Ecstasy was associated with poor concentration in the comedown period, and with mood fluctuation and impulsivity off-drug. PMQ long-term problems demonstrated a significant curvilinear relationship with thermal self-ratings; more memory problems were noted by those who felt very hot, and by those who did not feel hot when on Ecstasy.

CONCLUSIONS

Non-drug factors such as dancing and feeling hot are associated with the incidence of psychobiological problems reported by recreational Ecstasy/MDMA users.

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.