Mood disorders and serotonin transporter density in ecstasy users--the influence of long-term abstention, dose, and gender

RATIONALE

Neurotoxic effects of 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") on the serotonin (5-HT) system have been described in animals and humans, but little is known about long-term effects of ecstasy use on mood.

OBJECTIVES

To investigate short-term and long-term effects of ecstasy use on mood and its association with 5-HT neurotoxicity, dose, and gender in humans.

METHODS

Fifteen moderate ecstasy users, 23 heavy ecstasy users, 16 former heavy ecstasy users and 15 drug-using, but ecstasy-naive controls were included. Mood was assessed using the Composite International Diagnostic Interview (CIDI) and the Beck Depression Inventory (BDI). Outcomes were correlated with 5-HT transporter (SERT) density, assessed with [123I]beta-CIT single photon emission computed tomography (SPECT).

RESULTS

The prevalence of mood disorders assessed by CIDI did not differ between all groups. The overall test for differences in BDI scores between groups was near significance (P=0.056), with BDI scores higher in former heavy ecstasy users than in ecstasy-naive controls (P=0.045). BDI scores were correlated with the total number of ecstasy tablets used (r=0.310; P=0.021). No associations between CIDI or BDI outcomes and SERT density or gender were observed.

CONCLUSIONS

These results suggest that ecstasy use is not associated with clinical depression (CIDI). However, the number of ecstasy tablets taken lifetime was associated with higher BDI scores for depressive mood, and this relationship seemed to persist after ecstasy use had stopped. We did not find that depressed mood in ecstasy users was associated with decrease in SERT density. Prospective studies are needed to establish the causal relationship between ecstasy use and depressed mood.

Empathy and aggression: two faces of ecstasy? A study of interpretative cognitive bias and mood change in ecstasy users

RATIONALE

As central 5-hydroxytryptamine (5-HT) is attenuated for a period following a single dose of MDMA ("ecstasy") and low 5-HT is associated with aggression, then MDMA users may be more aggressive in the days following an acute dose of the drug.

OBJECTIVE

This study therefore aimed to determine if acute use of MDMA is associated with aggression 4 and 7 days later.

METHODS

Twenty-nine MDMA users and 32 controls were compared on self-rated aggression and depression on the night of drug use (day 0), 4 and 7 days later. On day 4, participants performed an interpretative bias task in which they processed ambiguous sentences that could be interpreted in either an aggressive or neutral way (e.g. "The painter drew the knife").

RESULTS

MDMA users had faster response times in completing ambiguous aggressive sentences than neutral sentences; controls showed the opposite pattern of performance. In a subsequent recognition task, MDMA users were more confident in judging, and responded faster to, aggressive than neutral sentences; controls again showed the opposite pattern of effects. The level of aggressive interpretative bias positively correlated with extent of MDMA use. Midweek, MDMA users had higher self-rated aggression and depression scores than controls; on day 7, scores of both groups were similar.

CONCLUSIONS

MDMA users display a cognitive bias towards interpreting ambiguous information in an aggressive way a few days after taking the drug. Self-rated mid-week low mood and mid-week aggression do not persist 7 days after use of the drug. This pattern of results is consistent both with the acute and residual effects of MDMA on central 5-HT and with the notion that 5-HT plays a role in modulating human aggression.

Preliminary evidence of hippocampal dysfunction in adolescent MDMA ("ecstasy") users: possible relationship to neurotoxic effects

RATIONALE

3,4-Methylenedioxymethamphetamine (MDMA or ecstasy) is a potent and selective serotonin neurotoxin whose use is growing among adolescents. Although cognitive deficits among adult MDMA users are well documented, little is known of the cognitive and brain functional sequelae of MDMA use during adolescence.

OBJECTIVE

We tested for evidence of cognitive deficits and changes in brain function in a pilot sample of adolescent MDMA users, who were compared with adolescent non-users of MDMA.

METHODS

Selective and divided attention and verbal working memory were examined in six adolescent MDMA users and six non-users of MDMA who were similar in age, gender, IQ, and other substance use. Brain function was assessed during performance of the working memory task using functional magnetic resonance imaging (fMRI).

RESULTS

MDMA users had significantly prolonged reaction times during tests of selective and divided attention, and failed to deactivate the left hippocampus normally during high verbal working memory load.

CONCLUSIONS

MDMA use in adolescence may be associated with cognitive impairments and dysfunction of inhibitory circuits within the hippocampus. Further work is urgently needed to delineate the developmental impact and long-term functional and clinical significance of MDMA use during adolescence.

Chronic MDMA (ecstasy) use, cognition and mood

RATIONALE

It has been suggested that 3,4-methylenedioxymethamphetamine (MDMA or ecstasy) causes damage to the serotonergic system, and that this damage results in cognitive and mood impairments.

OBJECTIVES

To examine the effect of chronic MDMA usage on a wide battery of cognitive tests and psychological abilities and processes.

METHODS

In the present study, the performance of 17 participants with a history of MDMA use was compared to the performance of 15 control subjects on a battery of neuropsychological tests. This battery included tests for depression, immediate word recall, delayed recall, attention and working memory.

RESULTS

Results indicated that the MDMA group had significantly higher scores for depression than the control group, and displayed poorer delayed recall and verbal learning than controls after accounting statistically for the effects of cannabis and depression.

CONCLUSIONS

These results suggest that MDMA users exhibit difficulties in coding information into long-term memory, display impaired verbal learning, are more easily distracted, and are less efficient at focusing attention on complex tasks.

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.

The application of the principles of clinical drug development to pharmacological challenge tests of the serotonergic system

Pharmacological challenge tests of the serotonergic system have extensively been used during the past 20 years and new tests are in development. It is of crucial importance to standardize challenge tests to ascertain that observed variability is due to the state of the challenged system and not caused by variability of the test itself. This is even more important now that challenge tests increasingly are used in complex studies (e.g. in combination with neuroimaging and in large population studies with repeated tests over time). The Guideline for Good Clinical Practice may be of great help in the standardization of these tests. This is a recently developed guideline for pharmaceutical drug-development, which increasingly is used as a reference for all research in humans. To exemplify the possible usefulness of this approach, we apply it to meta-chlorophenylpiperazine, one of the most commonly used drugs in serotonergic challenge tests. We conclude that much can be learned from the development of this particular challenge. In the discussion, we address general issues that emerged from this review and their relevance to the development of future challenge tests.

‘Ecstasy’-induced subarachnoid haemorrhage: an under-reported neurological complication?

In the face of escalating recreational use of 'Ecstasy' (3,4-methylenedioxymethamphetamine, MDMA), physicians need to be aware of its possible adverse effects. We report two young patients who suffered subarachnoid haemorrhage following ingestion of 'Ecstasy' tablets. Angiographic studies demonstrated features consistent with vasculitis in both cases. Recognition of this association is important and highlights the significance of eliciting a careful drug history, particularly in cases of 'angiogram negative' subarachnoid haemorrhage.

[Acute liver failure caused by Ecstasy]

Ecstasy is a synthetic amphetamine widely used as a "week-end" recreational drug because it produces euphoria and eliminate the sense of fatigue. It was initially considered to be a drug with few toxic effects, but later various complications and even fatal cases have been reported. Although the 23 year old woman already tried the Ecstasy in the past, but during the month before the admission she took 8 pills. She became icteric after 6 days taking the last pill and 3 days later her prothrombin level became very low. Due to the rapid deterioration we planed liver transplantation, but since there was no acceptable donor, we could only make plasmapheresis. The autopsy proved sever liver necrosis.

Risk of valvular heart disease associated with use of fenfluramine

BACKGROUND

Estimates of excess risk of valvular heart disease among prior users of fenfluramine and dexfenfluramine have varied widely. Two major forms of bias appear to contribute to this variability and also result in a systematic under-estimation of risk. The first, a form of nondifferential misclassification, is the result of including background, prevalent cases among both exposed and unexposed persons in calculations of risk. The second bias results from not considering the relatively short duration of exposure to drugs.

METHODS

We examined data from all available echocardiographic studies reporting the prevalence of aortic regurgitation (AR) and mitral regurgitation (MR) among persons exposed to fenfluramine or dexfenfluramine and a suitable control group. We also included one study in which previously existing AR or MR had been excluded. We corrected for background prevalent cases, estimated incidence rates in unexposed persons, and performed a person-years analysis of apparent incidence rates based on exposure time to provide an unbiased estimate of relative risk.

RESULTS

Appearance of new AR was strongly related to duration of exposure (R2 = 0.75, p < 0.0001). The summary relative risk for mild or greater AR was 19.6 (95% CI 16.3-23.5, p < 0.00001); for moderate or greater MR it was 5.9 (95% CI 4.0-8.6, p < 0.00001).

CONCLUSION

These findings provide strong support for the view that fenfluramine and dexfenfluramine are potent causal factors in the development of both aortic and mitral valvular heart disease.

Long-term effectiveness of risperidone and olanzapine in resistant or intolerant schizophrenic patients. A mirror study

OBJECTIVE

To evaluate the long-term effectiveness of the second generation antipsychotics, risperidone and olanzapine on hospitalization, clinical response, and adherence to therapy after switching from conventional antipsychotics or clozapine in a naturalistic setting of schizophrenic patients.

METHOD

Data were registered for periods of identical duration before and after switching.

RESULTS

Fifty-seven patients were included. Mean study period was 3.1 +/- 0.2 years. Mean number of in-patient days after switching declined by 78% of the level before switching (P=0.0002). There was no significant differences in ratio responders/non-responders between the subgroups. The number of patients with extrapyramidal symptoms (EPS) was significantly reduced after switching. However, intolerable weight gain led to a lack of adherence to therapy in 18% of the olanzapine-treated patients.

CONCLUSION

Long-term treatment with the second generation antipsychotics, risperidone and olanzapine significantly improved the clinical outcome. However, weight gain may be a significant reason for discontinuation of treatment and reducing the long-term adherence to therapy.

Mood, cognition and serotonin transporter availability in current and former ecstasy (MDMA) users

RATIONALE

Chronic recreational ecstasy (MDMA) use has often been reported to be associated with psychopathology, memory impairments and serotonergic alterations. However, the findings have not been consistent.

OBJECTIVES

To attempt to replicate these findings, to investigate whether such alterations would be reversible and whether they could be predicted by parameters of previous drug use.

METHODS

In a cross-sectional design, 30 current and 31 ex-ecstasy users with ecstasy abstinence of at least 5 months, and 29 polydrug and 30 drug-naive controls were compared on measures of psychopathology, cognitive performance and serotonin transporter availability.

RESULTS

The groups did not differ significantly in age, gender distribution, education level and premorbid intelligence. The ecstasy groups did not differ significantly from polydrug controls on most of the relevant parameters of concomitant illegal drug use. Reported drug use was confirmed by hair and urine analyses. All three groups of drug users exhibited significantly elevated psychopathology compared with drug-naive controls. Only ex-ecstasy users were significantly impaired on verbal recall. Current ecstasy users showed significantly reduced distribution volume ratios of serotonin transporter availability in the mesencephalon and caudate nucleus. Regression analyses indicated that psychopathology and serotonergic alterations were best predicted by the number of ecstasy tablets taken on a typical event.

CONCLUSION

The results indicate that verbal memory impairments were possibly aggravated after prolonged ecstasy abstinence while there was tentative evidence of serotonergic recovery. On the other hand, self-reported elevated psychopathology appeared to be associated with polydrug use in general and not specifically with ecstasy use.

Reduced social interaction following 3,4-methylenedioxymethamphetamine is not associated with enhanced 5-HT 2C receptor responsivity

This study examined the long-term change in serotonergic (5-hydroxytryptamine, 5-HT) neuronal function and 5-HT(2C) receptor agonist-induced behaviour following treatment of young rats with 3,4-methylenedioxymethamphetamine (MDMA). On post-natal day (PND) 28, Lister-hooded rats received either MDMA (15 mg/kg i.p.) or saline (1 ml/kg i.p.) twice daily for 3 days. On PND 50 social interaction was assessed between treatment-matched pairs of rats derived from separate litters. The effect of either the 5-HT(2C) receptor agonist, m-chlorophenylpiperazine (m-CPP, 2.5 or 1 mg/kg i.p., respectively) or saline was examined on open-field exploration (PND 52) and elevated plus-maze behaviour (PND 56). Acutely, MDMA produced hyperlocomotion and hypothermia compared with saline injection (p<0.001). Following 20 days abstinence, social interaction was decreased by 26% (p<0.05) in MDMA pre-treated rats compared with saline controls, without any change in locomotion. There was no difference in open-field or elevated plus-maze behaviour between pre-treatment groups. m-CPP caused hypolocomotion in the open-field and decreased both the percentage entries into, and time spent in, the open arms of the elevated plus-maze to a comparable extent in MDMA and saline pre-treated rats. Hippocampal and frontal cortical 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) were significantly reduced in MDMA pre-treated rats, without any change in [(3)H]paroxetine binding or plasma corticosterone levels. These data suggest that the MDMA-induced reduction in social interaction is not mediated via alteration of 5-HT(2C) receptor function.

The content of ecstasy tablets: implications for the study of their long-term effects

AIMS

To examine the variation in the content of ecstasy tablets seized in the north-west of England during 2001 and to compare it to the UK average from 1991 to 2001.

MEASUREMENTS

All tablets submitted to the Forensic Science Service in the north-west of England during 2001 were analysed by high performance liquid chromatography with diode array detection (HPLC-DAD). The mean MDMA content of these tablets are reported and compared to results from all Forensic Science Service laboratories in the United Kingdom from 1991 to 2001. Multiple samples (n= 80) from a single large seizure of White Dove tablets were analysed to determine the variation due to manufacturing.

FINDINGS

All tablets submitted from the north-west of England to the Forensic Science Service in 2001 were found to contain 3,4-methylenedioxymethamphetamine (MDMA) and some also contained 3,4-methylenedioxyethamphetamine (MDEA). The MDMA content of these tablets ranged from 20 to 109 mg and the mean was in the 60-69 mg range. Mitsubishi tablets were the most common type and they were found across the whole range. The low variation of MDMA content in the White Dove tablets suggests that these tablets were well manufactured. The data from the north-west of England in 2001 are in agreement with tablet analyses over the past 10 years which show that the average MDMA content is falling.

CONCLUSIONS

The amount of MDMA in ecstasy tablets is axiomatic to the discussion of their long-term effects. In order for the observed differences in ecstasy users to be the result of MDMA-induced neurotoxicity it is necessary for them to have ingested one or more neurotoxic doses. These data indicate that the amount of MDMA in ecstasy tablets is dropping and that dose-effect relationships need to take this into account.

Effect of fenfluramine-derivative diet pills on cardiac valves: a meta-analysis of observational studies

BACKGROUND

Fenfluramine-derivative diet pills were withdrawn from the market in 1997 because of an association with valvular regurgitation, but subsequent estimates of the prevalence of this condition have varied widely. We systematically reviewed evidence regarding the prevalence of valvular disease after fenfluramine exposure.

METHODS

We searched multiple databases with multiple search terms. Conference proceedings from 1997 onward were searched by index. Authors of eligible studies were contacted to identify unpublished works. Selection criteria were liberally determined. Ten of the identified 11 articles met these criteria. Reviewers assessed the studies' methodologic quality by use of a standard form to evaluate selection, attrition, performance, and detection bias. The studies were analyzed in 2 groups on the basis of length of exposure (<90 days or >90 days). The Mantel-Haenszel method was used to summarize data. Quantitative and qualitative tests for heterogeneity were performed. Tests for publication bias were also done.

RESULTS

Tests for heterogeneity were nonsignificant after removing 1 outlier trial. The pooled prevalence of valvular regurgitation meeting Food and Drug Administration criteria (at least mild aortic regurgitation or at least moderate mitral regurgitation) among patients treated for >90 days was 12.0% compared with 5.9% for the unexposed group (prevalence odds ratio 2.2, 95% CI 1.7-2.7). The combined analyses also identified a small but statistically significant increase in mitral regurgitation not previously identified by individual studies (exposed 3.5%, unexposed 1.8%, prevalence odds ratio 1.6, 95% CI 1.05-2.3). Among patients exposed for <90 days, a trend toward more regurgitation was not statistically significant by either combined Food and Drug Administration criteria (exposed 6.8%, unexposed 5.8%, prevalence odds ratio 1.4, 95% CI 0.8-2.4) or by individual valve.

CONCLUSIONS

These data indicate that fenfluramine-associated valvular regurgitation is less common than initially reported, but still present in 1 of 8 patients treated for >90 days.

Major depressive episodes and diet pills

A variety of medications used to assist with weight loss have been implicated in the precipitation or induction of depressive symptoms and disorders. This is true of a large number of phenylethylamine agents possessing psychostimulant properties, non-phenylethylamine psychostimulants (e.g., caffeine) and the serotonergic agent, fenfluramine. There is, as yet, no substantial evidence linking the more modern weight loss drugs, sibutramine and orlistat, to the aetiology of major depression. Nevertheless, when these drugs are used, major depression will continue to be an important clinical consideration because of the elevated frequency with which major depression occurs in obese patients, the contribution that major depression may make to poor outcomes in non-pharmacological weight loss treatment and because of the interplay between symptoms of depression and weight loss treatment.

[Serotonin syndrome]

The serotonin syndrome is a hyperserotoninergic state resulting from an excess of intrasynaptic 5-hydroxytryptamine, induced by multiple psychotropic agents, but also non psychiatric drugs. It is a potentially dangerous and sometimes lethal condition. The clinical manifestations usually include cognitive, neuromuscular and autonomic features and are mediated by the action of serotonin on various subtypes of receptors. The main differential diagnosis is the neuroleptic malignant syndrome. Treatment is mainly supportive. No pharmacological agent has been definitely demonstrated really effective. However, reports of cases treated with the 5-HT2 blockers, including cyproheptadine or chlorpromazine have suggested that these agents could have some efficacy. Serotonin syndrome is a toxic condition which requires heightened clinical awareness among physicians in order to prevent, recognize, and treat the condition promptly.

Serotonin syndrome: a reported case

We describe a patient treated with SSRI and Ldopa, who developed agitation, rigidity, hyperreflexia, restlessness, autonomic instability, fever and finally death. CSF examination, MRI of the brain, laboratory investigations, except for serum CK, glycemia and WBC, were normal. His condition was thought to result from an central serotonin activity. The serotonin syndrome occurs following the use of serotomimetic agents (serotonin reuptake inhibitors, tricyclic and tetracyclic antidepressants, tryptophan alone or in combination with monoamine oxidase inhibitors).

Therapeutic and adverse actions of serotonin transporter substrates

A variety of drugs release serotonin (5-HT, 5-hydroxytryptamine) from neurons by acting as substrates for 5-HT transporter (SERT) proteins. This review summarizes the neurochemical, therapeutic, and adverse actions of substrate-type 5-HT-releasing agents. The appetite suppressant (+/-)-fenfluramine is composed of (+) and (-) isomers, which are N-de-ethylated in the liver to yield the metabolites (+)- and (-)-norfenfluramine. Fenfluramines and norfenfluramines are potent 5-HT releasers. (+/-)-3,4-Methylenedioxymethamphetamine ((+/-)-MDMA, "ecstasy") and m-chlorophenylpiperazine (mCPP) are substrate-type 5-HT releasers. Fenfluramines, (+/-)-MDMA, and mCPP release neuronal 5-HT by a common non-exocytotic diffusion-exchange mechanism involving SERTs. (+)-Norfenfluramine is a potent 5-HT(2B) and 5-HT(2C) receptor agonist. The former activity may increase the risk of valvular heart disease, whereas the latter activity is implicated in the anorexic effect of systemic fenfluramine. Appetite suppressants that increase the risk for developing primary pulmonary hypertension (PPH) are all SERT substrates, but these drugs vary considerably in their propensity to increase this risk. For example, fenfluramine and aminorex are clearly linked to the occurrence of PPH, whereas other anorectics are not. Similarly, some SERT substrates deplete brain tissue 5-HT in animals (e.g., fenfluramine), while others do not (e.g., mCPP). In addition to the established indication of obesity, 5-HT releasers may help treat psychiatric disorders, such as drug and alcohol dependence, depression, and premenstrual syndrome. Viewed collectively, we believe new medications can be developed that selectively release 5-HT without increasing the risk for adverse effects of valvular heart disease, PPH, and neurotoxicity. Such agents may be useful for treating a variety of psychiatric disorders.

Increased anxiety in rats after 3,4-methylenedioxymethamphetamine: association with serotonin depletion

The long-term behavioural and neurotoxic effects of 3,4-methlyenedioxymethampthetamine (MDMA, "Ecstasy") were examined in rats. Rats were given MDMA (5 mg/kg i.p. once per hour for 4 h) or vehicle injections on each of two consecutive days at an ambient temparature of 28 degrees C. MDMA caused acute hyperthermia and locomotor hyperactivity on both days. Four and six weeks after drug administration the rats previously treated with MDMA showed elevated levels of anxiety-like behaviour in the emergence and social interaction tests, respectively. At 9 weeks post-MDMA, the rats displayed an increase in anxiety on the elevated plus-maze test relative to controls. Ten weeks following treatment the rats were killed and their brains dissected and neurotramitter content analysed using High Performance Liquid Chromotography (HPLC). Rats previously given MDMA showed significantly decreased 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in the amygdala, hippocampus and striatum relative to controls. This 5-HT depletion may have a causal role in producing increased anxiety-like behaviours in MDMA-treated rats. These results are consistent with human studies suggesting that exposure to high doses of MDMA may predispose to long-term psychological problems such as anxiety and depression.

Enhanced inhibitory avoidance training protects against the amnesic effect of p-chloroamphetamine

The contribution of acetylcholine (ACh) to memory processing is well documented, but it has been proposed that it is not necessary for memory consolidation after an enhanced learning experience. It has been suggested that serotonin (5-HT) interacts with ACh during memory consolidation, although the nature of this interaction is unknown in the case of strong learning. As an initial approach to the study of these interactions, we determined whether training of inhibitory avoidance using relatively high aversive stimulation protects against the typical retention deficits produced by pre-training administration of the 5-HT releaser p-chloroamphetamine (PCA). Rats were trained after intraperitoneal administration of PCA or isotonic saline, using 2.0, 2.5, 3.0 or 3.5 mA and retention of the task was measured 24 h later. A significant amnesic state was observed only in the PCA groups that had been trained with the two lower intensities. These results indicate that 5-HT systems behave similarly to ACh systems, in the sense that the amnesic effect produced by interference with their physiological activity may be cancelled when animals are submitted to an intense learning situation.

Serotonin releasing agents. Neurochemical, therapeutic and adverse effects

This review summarizes the neurochemical, therapeutic and adverse effects of serotonin (5-HT) releasing agents. The 5-HT releaser (plus minus)-fenfluramine is composed of two stereoisomers, (+)-fenfluramine and (minus sign)-fenfluramine, which are N-de-ethylated to yield the metabolites, (+)-norfenfluramine and (minus sign)-norfenfluramine. Fenfluramines and norfenfluramines are 5-HT transporter substrates and potent 5-HT releasers. Other 5-HT releasing agents include m-chlorophenylpiperazine (mCPP), a major metabolite of the antidepressant drug trazodone. Findings from in vitro and in vivo studies support the hypothesis that fenfluramines and mCPP release neuronal 5-HT via a non-exocytotic carrier-mediated exchange mechanism involving 5-HT transporters. (+)-Norfenfluramine is a potent 5-HT(2B) and 5-HT(2C) receptor agonist. The former activity may increase the risk of developing valvular heart disease (VHD), whereas the latter activity is implicated in the anorectic effect of systemic fenfluramine. Anorectic agents that increase the risk of developing primary pulmonary hypertension (PPH) share the common property of being 5-HT transporter substrates. However, these drugs vary considerably in their propensity to increase the risk of PPH. In this regard, neither trazodone nor mCPP is associated with PPH. Similarly, although some 5-HT substrates can deplete brain 5-HT (fenfluramine), others do not (mCPP). In addition to the established indication of obesity, 5-HT releasers may be helpful in treating psychiatric problems such as drug and alcohol dependence, depression and premenstrual syndrome. Viewed collectively, it seems possible to develop new medications that selectively release 5-HT without the adverse effects of PPH, VHD or neurotoxicity. Such agents may have utility in treating a variety of psychiatric disorders.

How strong is the evidence that brain serotonin neurons are damaged in human users of ecstasy?

Understanding the diverse functions of serotonin in the human brain can be obtained through examination of subjects having a lower than normal number of brain serotonin neurons. Behavioral abnormalities consistent with brain serotonergic damage have been reported in some polydrug users who also use the neurotoxin ecstasy (methylenedioxymethamphetamine, MDMA). This review evaluates the evidence from neuroimaging studies that brain serotonergic damage is a feature of human users of ecstasy. To date, neuroimaging studies designed to establish whether levels of brain serotonin neurons are lower than normal in ecstasy users have employed radioligands that bind to one component of the serotonin neuron, the serotonin transporter (SERT). Because these studies are methodologically flawed in terms of reliability or validity of the SERT measurement and appear to have employed polydrug users, no definitive information is yet available on the question of ecstasy toxicity to human brain serotonin neurons. Until these issues are resolved, it cannot be assumed that ecstasy exposure represents a chronic serotonin deficiency condition.

Recreational Ecstasy/MDMA, the serotonin syndrome, and serotonergic neurotoxicity

The ring-substituted amphetamine derivative 3,4-methylenedioxymethamphetamine (MDMA) or "Ecstasy" is widely used a recreational drug. It stimulates the release and inhibits the reuptake of serotonin (5-HT) and other neurotransmitters such as dopamine to a lesser extent. The acute boost in monoamine activity can generate feelings of elation, emotional closeness, and sensory pleasure. In the hot and crowded conditions of raves/dances, mild versions of the serotonin syndrome often develop, when hyperthermia, mental confusion, and hyperkinesia predominate. Rest in a cooler environment generally reverses these problems, although they can develop into medical emergencies, which occasionally prove fatal. This acute serotonergic overactivity is exacerbated by the high ambient temperatures, overcrowding (aggregate toxicity), and use of other stimulant drugs. The on-drug experience is generally followed by negative moods, with 80--90% of weekend Ecstasy users reporting 'midweek blues', due probably to monoaminergic depletion. Single doses of MDMA can cause serotonergic nerve damage in laboratory animals, with repeated doses causing extensive loss of distal axon terminals. Huether's explanatory model for this 5-HT neurotoxicity will be briefly described. There is an increasing body of evidence for equivalent neuropsychobiological damage in humans. Abstinent regular Ecstasy users often show: reduced cerebrospinal 5-HIAA, reduced density of 5-HT transporters, blunted response to a fenfluramine challenge, memory problems, higher cognitive deficits, various psychiatric disorders, altered appetite, and loss of sexual interest. Functional deficits may remain long after drug use has ceased and are consistent with serotonergic axonal loss in higher brain regions.

Review article: the complexity of drug development for irritable bowel syndrome

Drug development for functional gastrointestinal disorders is complex. These conditions involve central and peripheral physiological changes, together with psychological factors. Methodological problems have included a poor appreciation of the physiological and psychological correlates of patients' symptoms, a lack of animal models of proven relevance, and safety issues. Government, patient pressure groups and the Internet can also influence a drug's success. Most recent interest has focused on the serotonin (5-HT) modifying drugs. Cisapride has been withdrawn in some countries because of concerns related to QT prolongation and cardiac arrhythmias. The 5-HT3 antagonists, developed to modify visceral sensation, have caused constipation; alosetron, also withdrawn, caused ischaemic colitis. The 5-HT4 agonists induce peristalsis; tegaserod and prucalopride, both delayed in their development due to issues of safety and efficacy, benefit patients with 'constipation-predominant' irritable bowel syndrome or idiopathic constipation. 5-HT1 agonists improve impaired gastric accommodation and symptoms in patients with functional dyspepsia. Antidepressants also affect serotonin metabolism. Previous examples of success in this area involved drugs targeted at peripheral receptors mediating motor function or secretion. Modification of sensory function is a much more challenging objective. The experience with serotonin modifying drugs has been mixed, and some important lessons are there to be learnt.

Ecstasy (MDMA): are the psychological problems associated with its use reversed by prolonged abstinence?

RATIONALE

Chronic, regular recreational use of ecstasy (MDMA) is associated with psychopathology, elevated behavioural impulsivity and persistent impairment of memory performance.

OBJECTIVE

The aim of the present study was to investigate which of these sequelae persist after at least 6 months of abstinence from ecstasy.

METHODS

Four groups of participants were compared: 18 current regular recreational ecstasy users, 15 ex-regular ecstasy users who had abstained from using the drug for an average of 2 years, 16 polydrug users who had never taken ecstasy and 15 drug-naive controls.

RESULTS

There were no significant group differences in age, education level, or pre-morbid intelligence and, generally, the use of illicit drugs other than ecstasy was not significantly different among the three drug-using groups. Both current and ex-ecstasy users exhibited elevated psychopathology and behavioural impulsivity compared with polydrug users and drug-naive controls, but current ecstasy users exhibited a broader range of psychopathology than ex-users. Both groups of ecstasy users also exhibited impaired working memory and verbal recall performance compared with drug-naive controls, but only ex-users exhibited impaired verbal recall relative to polydrug users. Regression analysis indicated that psychopathology was primarily predicted by the extent of previous consumption of cannabis rather than ecstasy, whereas the majority of the cognitive deficits were only predicted by the extent of previous ecstasy use.

CONCLUSIONS

Selective impairments of neuropsychological performance associated with regular ecstasy use are not reversed by prolonged abstinence. This is consistent with evidence that ecstasy has potent and selective neurotoxic effects on brain serotonergic systems in humans.

Effects of dose, sex, and long-term abstention from use on toxic effects of MDMA (ecstasy) on brain serotonin neurons

BACKGROUND

3,4-methylenedioxymethamphetamine (MDMA or ecstasy) is a popular recreational drug that has been shown to damage brain serotonin neurons in high doses. However, effects of moderate MDMA use on serotonin neurons have not been studied, and sex differences and the long-term effects of MDMA use on serotonin neurons have not been identified. We investigated the effects of moderate and heavy MDMA use, sex differences, and long-term effects of MDMA use on serotonin neurons in different brain regions.

METHODS

By means of flyers posted in "rave" venues in Amsterdam, the Netherlands, we recruited 15 moderate MDMA users, 23 heavy MDMA users, 16 ex-MDMA users who had stopped using MDMA for more than 1 year, and 15 controls who claimed never to have used MDMA. We studied the effects of MDMA on brain serotonin neurons using 123iodine-2beta-carbomethoxy-3beta-(4-iodophenyl) tropane ([123I]beta-CIT)-a radioligand that binds with high affinity to serotonin transporters. Density of binding (expressed as a ratio of region-of-interest binding over binding in the cerebellum) was calculated by single-photon-emission computed tomography (SPECT).

FINDINGS

We saw significant effects of group and group by sex (p=0.041 and p=0.022, respectively) on overall [123I]beta-CIT binding ratios. In heavy MDMA users, significant decreases in overall binding ratios were seen in women (p<0.01) but not men (p=0.587). In female ex-MDMA users, overall densities of serotonin transporters were significantly higher than in heavy MDMA users (p=0.004), but not higher than in controls (p=0.524).

INTERPRETATION

Our results indicate that heavy use of MDMA is associated with neurotoxic effects on serotonin neurons, that women might be more susceptible than men, and that MDMA-induced neurotoxic changes in several brain regions of female ex-MDMA users are reversible.

Recreational ecstasy/MDMA and other drug users from the UK and Italy: psychiatric symptoms and psychobiological problems

RATIONALE

Recreational drug use is increasingly widespread amongst young people, but there are concerns that psychoactive drugs may be associated with psychiatric symptoms or psychobiological problems.

OBJECTIVES

To assess the psychiatric health status of a large, non-clinical sample of young adults from Italy and the UK, and relate it to their use of ecstasy/MDMA and other recreational drugs.

METHODS

The UEL Recreational Drug Use Questionnaire was completed by 768 young people (mean age 21.7 years) from four European cities. The subjects comprised 150 non-drug users, 185 alcohol/tobacco users, 97 cannabis and alcohol/tobacco users, 102 illicit polydrug but not ecstasy users, 115 light (<20 times) ecstasy polydrug users, and 119 heavy (>20 times) ecstasy polydrug users. The unpaid volunteers completed the SCL-90 self-rating inventory for psychiatric symptoms when off drug, with 30 additional questions covering positive moods and life experiences.

RESULTS

Heavy ecstasy polydrug users reported significantly higher scores than non-drug users on several SCL-90 factors, including phobic anxiety, obsessive-compulsive behaviour, anxiety, psychoticism, somatisation, and significantly higher rates of 'loss of sex interest or pleasure'. Self-rated symptom scores increased in line with greater drug use, so that polydrug users who had never taken ecstasy also reported a variety of psychobiological impairments. In contrast, positive moods and life experiences were broadly similar across subgroups.

CONCLUSIONS

The recreational use of ecstasy/MDMA is associated with a range of psychiatric symptoms and psychobiological problems. However, these problems are not specific to ecstasy users but are also evident in other recreational polydrug users.

Clinical and echocardiographic follow-up of patients previously treated with dexfenfluramine or phentermine/fenfluramine

CONTEXT

Use of anorexigen therapy is associated with valvular abnormalities, although there is limited information on long-term changes in valvular regurgitation following discontinuation of these agents.

OBJECTIVE

To evaluate changes in valvular regurgitation, valve morphology, and clinical parameters 1 year after an initial echocardiogram in patients previously treated with dexfenfluramine or phentermine/fenfluramine and in untreated controls.

DESIGN AND SETTING

A reader-blinded, multicenter, echocardiographic and clinical 1-year follow-up study at 25 outpatient clinical sites.

PATIENTS

A total of 1142 obese patients (1466 participated in the initial study) who had follow-up echocardiogram; all but 4 had a follow-up medical history and physical examination. Follow-up time from discontinuation of drug to follow-up echocardiogram for 371 dexfenfluramine patients was 17.5 months (range, 13-26 months) and for 340 phentermine/fenfluramine patients was 18.7 months (range, 13-26 months) after discontinuation of drug therapy.

MAIN OUTCOME MEASURE

Change in grade of valvular regurgitation and valve morphology and mobility.

RESULTS

Echocardiographic changes in aortic regurgitation were observed in 8 controls (7 [1.7%] had decreases; 1 [0.2%] had an increase); 29 dexfenfluramine patients (23 [6.4%] had decreases; 6 [1.7%] had increases; P<.001 vs controls); and 15 phentermine/fenfluramine patients (4.5% all decreases; P =.03 vs controls). No statistically significant differences were observed when treated patients were compared with controls for changes in medical history, physical findings, mitral regurgitation, aortic or mitral leaflet mobility or thickness, pulmonary artery systolic pressure, ejection fraction, valve surgery, or cardiovascular events.

CONCLUSION

Progression of valvular abnormalities is unlikely in patients 1 year after an initial echocardiogram and 13 to 26 months after discontinuation of dexfenfluramine and phentermine/fenfluramine.

Operation for anorexigen-associated valvular heart disease

OBJECTIVES

Recently, valvular regurgitation has been observed in patients who have taken fenfluramine or dexfenfluramine with or without phentermine. This study describes the clinical, echocardiographic, and pathologic findings of anorexigen-associated valvular heart disease and the surgical interventions required to treat it.

METHODS

We reviewed clinical information on 14 patients with severe anorexigen-associated valvular disease who underwent cardiac operations.

RESULTS

Thirteen women (mean age 44.2 +/- 5.3 years) received fenfluramine, 58.5 +/- 22.3 mg/day, and phentermine, 32.1 +/- 11.4 mg/day, for an average of 12.1 +/- 7.3 months before presentation. One woman received dexfenfluramine, 30 mg/day for 13 months, and phentermine, 60 mg/day, concomitantly for 6 months. Presenting symptoms included dyspnea (12 cases), palpitations (3), and atypical chest pain (3). Six patients had heart failure, and 4 had a new murmur. Echocardiography demonstrated severe mitral valve regurgitation in all patients. Seven also had aortic regurgitation, and 4 had significant tricuspid regurgitation. Four patients had successful mitral valve repair, 1 with concomitant aortic valve repair. Ten additional patients eventually required mitral valve replacement, 5 with concomitant aortic valve replacement. Excised valves demonstrated a glistening white appearance with plaque-like encasement of leaflets and chordae. Focal surface proliferation and fibrosis with a "stuck-on" appearance was consistently found.

CONCLUSIONS

Anorexigen use may lead to severe multivalvular regurgitation with characteristic echocardiographic and pathologic findings. Recognition of drug-induced valvulopathy is important because of widespread use of these medications and the uncertain natural history of the disease. Early surgical experience suggests that valve repair is possible in these young patients.

Echocardiographic examination of women previously treated with fenfluramine: long-term follow-up of a randomized, double-blind, placebo-controlled trial

BACKGROUND

Fenfluramine hydrochloride was withdrawn from the market in September 1997 after reports of heart valve abnormalities in patients who used it. The prevalence of echocardiographic abnormalities and the clinical cardiovascular status of patients who received fenfluramine monotherapy remains uncertain.

METHODS

A long-term, follow-up evaluation was undertaken in subjects who were randomly assigned to receive either fenfluramine hydrochloride (60 mg daily) or placebo as part of a double-blind smoking cessation therapy study. Cardiovascular status was evaluated by echocardiography, medical history, and physical examination.

RESULTS

From the group of 720 smokers who had originally participated in the smoking cessation therapy trial, 619 women were enrolled; data from 530 (276 in the fenfluramine group and 254 in the placebo group) were evaluable. No statistically significant differences were identified in the prevalence of aortic or mitral regurgitation by Food and Drug Administration criteria or by grade, aortic or mitral valve leaflet mobility restriction or thickening, elevated pulmonary artery systolic pressure, or abnormal left ventricular ejection fraction. No significant differences were demonstrated in cardiovascular status by physical examination, and no serious cardiac events were noted among fenfluramine-treated subjects.

CONCLUSION

There was no evidence of drug-related heart disease up to 4.9 years after anorexigen therapy in subjects who were randomly assigned to receive fenfluramine at the recommended dose for up to 3 months.

The role of serotonin transporter protein gene in antidepressant-induced mania in bipolar disorder: preliminary findings

BACKGROUND

The occurrence of mania during antidepressant treatment is a key issue in the clinical management of bipolar disorder (BP). The serotonin transporter (5-HTT) is the selective site of action of most proserotonergic compounds used to treat bipolar depression. The 5-HTT gene (SLC6A4) has 2 known polymorphisms. The aim of this study was to investigate the role of the SLC6A4 variants in the pathogenesis of antidepressant-induced mania in BP.

METHODS

Twenty-seven patients with a DSM-IV diagnosis of BP I or II, with at least 1 manic or hypomanic episode induced by treatment with proserotonergic antidepressants (IM+ group), were compared with 29 unrelated, matched patients with a diagnosis of BP I or II, who had been exposed to proserotonergic antidepressants without development of manic or hypomanic symptoms (IM- group). The 2 known polymorphisms of the SLC6A4 were genotyped, and allelic and genotypic association analyses were performed.

RESULTS

With respect to the polymorphism in the promoter region (5HTTLPR), IM+ patients had an excess of the short allele (n = 34 [63%]) compared with IM- patients (n = 17 [29%]) (chi(2)(1), 12.77; P <.001). The genotypic association analysis showed a higher rate of homozygosity for the short variant in the IM+ group (n = 10 [37%]) than in the IM- group (n = 2 [7%]) and a lower rate of homozygosity for the long variant in the IM+ group (n = 3 [11%]) compared with the IM- group (n = 14 [48%]) (chi(2)(2), 12.43; P =.002). No associations were found for the polymorphism involving a variable number of tandem repeats.

CONCLUSION

If these results are replicated, the 5HTTLPR polymorphism may become an important predictor of abnormal response to medication in patients with BP.

Hippocampal 1H-MRSI in ecstasy users

In recent years the illicit drug ecstasy (MDMA, 3,4-methylenedioxymethamphetamine) has come into widespread use among young people. Despite clear evidence for the neurotoxic potential of MDMA in animals, corresponding evidence in humans is limited to indirect findings. In an exploratory study we compared the hippocampal 1H-MRSI (magnetic resonance spectroscopic imaging) spectra of five MDMA users with those of controls with no history of substance abuse. Although 1H

The progression of fenfluramine-associated valvular heart disease assessed by echocardiography

BACKGROUND

An association between the dietary suppressants fenfluramine and dexfenfluramine and valvular heart disease was first described in patients from North Dakota and Minnesota in 1997. Limited data are available on the natural history of this valvulopathy after discontinuation of drug therapy.

OBJECTIVE

To follow the progression of fenfluramine-associated valvular heart disease after discontinuation of therapy by using serial echocardiography.

DESIGN

Retrospective cohort study.

SETTING

Regional medical center in Fargo, North Dakota.

PATIENTS

50 patients with previous exposure to fenfluramines who had at least mild mitral regurgitation or aortic regurgitation after exposure to fenfluramines on serial echocardiography between December 1994 and February 1999 (96% were female, mean body mass index was 36.6 kg/m(2), and mean duration of drug exposure was 447 days).

MEASUREMENTS

Serial echocardiograms were reviewed by two echocardiographers who were blinded to the order of image acquisition. The severity of valvular regurgitation and presence or absence of valve leaflet restriction were assessed.

RESULTS

As described in the initial report, significant valvular disease on initial postexposure echocardiography was common in this cohort; 38 patients (76%) had at least mild mitral regurgitation and 43 patients (86%) had at least mild aortic regurgitation. On serial echocardiograms obtained an average of 356 days apart, mitral regurgitation improved by at least one grade in 17 patients (P = 0.001) and aortic regurgitation improved by at least one grade in 19 patients (P = 0.004). Nineteen and 22 patients, respectively, experienced no change in severity of mitral and aortic regurgitation. Two patients in each group experienced worsening of regurgitation by at least one grade. Results were similar for tricuspid (P = 0.002) and pulmonic (P = 0.012) regurgitation.

CONCLUSION

On serial echocardiography, fenfluramine-associated valvular regurgitation improved or remained stable in most patients after therapy ended. Worsening of valvular regurgitation was uncommon. The potential for stabilization or regression of valvular regurgitation should be taken into account when counseling patients and considering the need for and timing of valve surgery.