High drug related mortality rates following prison release: Assessing the acceptance likelihood of a naltrexone injection and related concerns.

BACKGROUND AND AIMS: High drug related mortality amongst former prisoners in the 4 weeks following release is an internationally recognised problem. Naltrexone injections at release could diminish this by blockading opioid receptors, but naltrexone is not licensed for injection for treating opiate misuse in the United Kingdom and some other countries. This study examined the likelihood of accepting a naltrexone injection at release, and the relationship of this likelihood to other relevant variables. METHOD: Sixty-one male prisoners with a history of heroin use, who were approaching release from two prisons in the north-west of England, provided likelihood ratings for accepting a naltrexone injection if it were to have been available. Additional data was gathered regarding demographic and drug use histories, and also from psychometric instruments relevant to drug misuse and treatment preparedness. RESULTS: Maximum likelihood ratings for accepting a naltrexone injection were recorded by 55.7% of the sample with only 9.8% indicating no likelihood of accepting an injection. Likelihood ratings were positively related to serving a current sentence for an acquisitive offence compared to drug related or violence offences, and negatively related to peak methadone dosages during the current sentence. CONCLUSIONS: Although naltrexone injections were not available to participants in this study, the findings suggest that the potential uptake for this intervention is sufficient to warrant a clinical trial with this population of British prisoners, with a view to potential changes to its current licencing status. However, the importance of individual patient readiness for such an abstinence orientated intervention is emphasised by the negative correlation between the likelihood ratings and recent methadone doses.

The relationships of 'ecstasy' (MDMA) and cannabis use to impaired executive inhibition and access to semantic long-term memory.

This study aimed to examine the relationship between the consumption of ecstasy (3,4-methylenedioxymethamphetamine (MDMA)) and cannabis, and performance on the random letter generation task which generates dependent variables drawing upon executive inhibition and access to semantic long-term memory (LTM). The participant group was a between-participant independent variable with users of both ecstasy and cannabis (E/C group, n = 15), users of cannabis but not ecstasy (CA group, n = 13) and controls with no exposure to these drugs (CO group, n = 12). Dependent variables measured violations of randomness: number of repeat sequences, number of alphabetical sequences (both drawing upon inhibition) and redundancy (drawing upon access to semantic LTM). E/C participants showed significantly higher redundancy than CO participants but did not differ from CA participants. There were no significant effects for the other dependent variables. A regression model comprising intelligence measures and estimates of ecstasy and cannabis consumption predicted redundancy scores, but only cannabis consumption contributed significantly to this prediction. Impaired access to semantic LTM may be related to cannabis consumption, although the involvement of ecstasy and other stimulant drugs cannot be excluded here. Executive inhibitory functioning, as measured by the random letter generation task, is unrelated to ecstasy and cannabis consumption.

Executive working memory deficits in abstinent ecstasy/MDMA users: a critical review.

AIMS: This review examined studies of executive functioning in abstinent ecstasy (3,4-methylenedioxymethamphetamine, MDMA) users on tasks which had been empirically mapped onto updating, shifting, inhibition and accessing long-term memory executive processes. Studies of some aspects of visuospatial memory performance were also included because of the investment of executive resources in such tasks. METHODS: Thirty-three studies were identified for the review following searches of the Psychinfo and Medline databases. Inclusion criteria were the reporting of new empirical findings from participants drug free at the time of testing, in peer-reviewed journals in the English language. RESULTS: Evidence for ecstasy-related performance deficits was strongest for the updating of verbal material, and for visuospatial memory tasks requiring additional processing beyond storage and retrieval. Such processing suggested that the overall level of executive demand was an important consideration. Executive shifting showed little evidence of ecstasy-related impairment, whilst examination of inhibition and long-term memory access presented an unclear picture. CONCLUSIONS: All but one of the studies had a cross-sectional design. Although this is a potential weakness with regard to confounds, the necessity of such designs was acknowledged. Studies were generally aware of the need to control for potential confounds, especially the effects of other drugs, through a mixture of group designs and statistical techniques. It was recommended that future studies of executive functioning in ecstasy users should detail the relationship of the tasks and dependent variables reported to specific executive processes and consider the level of executive demand imposed by such tasks.

The impact of citrate introduction at UK syringe exchange programmes: a retrospective cohort study in Cheshire and Merseyside, UK.

BACKGROUND: In 2003, it became legal in the UK for syringe exchange programmes (SEPs) to provide citrate to injecting drug users to solubilise heroin. Little work has been undertaken on the effect of policy change on SEP function. Here, we examine whether the introduction of citrate in Cheshire and Merseyside SEPs has altered the number of heroin/crack injectors accessing SEPs, the frequency at which heroin/crack injectors visited SEPs and the number of syringes dispensed. METHODS: Eleven SEPs in Cheshire and Merseyside commenced citrate provision in 2003. SEP-specific data for the six months before and six months after citrate was introduced were extracted from routine monitoring systems relating to heroin and crack injectors. Analyses compared all individuals attending pre and post citrate and matched analyses only those individuals attending in both periods (defined as 'longitudinal attenders'). Non-parametric tests were used throughout. RESULTS: Neither new (first seen in either six months period) nor established clients visited SEPs more frequently post citrate. New clients collected significantly less syringes per visit post citrate, than pre citrate (14.5,10.0; z = 1.992, P < 0.05). Matched pair analysis showed that the median number of visits for 'longitudinal attenders' (i.e. those who attended in both pre and post citrate periods) increased from four pre citrate to five post citrate (z = 2.187, P < 0.05) but the number of syringes collected remained unchanged. These changes were not due to seasonal variation or other changes in service configuration. CONCLUSION: The introduction of citrate did not negatively affect SEP attendance. 'Longitudinal attenders' visited SEPs more frequently post citrate, providing staff with greater opportunity for intervention and referral. As the number of syringes they collected each visit remained unchanged the total number of clean syringes made available to this group of injectors increased very slightly between the pre and post citrate periods. However, new clients collected significantly less syringes post citrate than pre citrate, possibly due to staff concerns regarding the amount of citrate (and thus syringes) to dispense safely to new clients. These concerns should not be allowed to negatively impact on the number of syringes dispensed.

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.

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.

Users' perceptions of the risks and effects of taking ecstasy (MDMA): a questionnaire study.

This self-report questionnaire study examined ecstasy users' perceptions of the risks associated with their use of ecstasy, their precautions against such risks, and its perceived effects on their lives. Gender differences in these areas were also explored. The sample comprised 328 ecstasy users (139 female, 187 male, one transsexual) with a mean age of 22.5 years (SD = 4.9 years). Questionnaires were completed either in hard copy or through a website concerned with ecstasy use. The results showed that friends were the most common source of information about ecstasy for the sample overall, although females were more likely to utilize this source than males. None of the five categories of perceived risk (e.g. psychiatric, physical) showed a significant gender difference. Males were more likely to take rest breaks whilst females were more likely to limit consumption as a precaution against harm. Three factors emerged from a principal components analysis concerning perceived personal change since initiation of ecstasy use. Factor 1 (23.8% of the variance) concerned negative experiences (e.g. depression). Factor 2 (22.0% of the variance) concerned positive personal qualities (e.g. caring). Factor 3 (10.5% of the variance) concerned selective aspects of functioning (e.g. alertness). The pattern of Factor 1 and Factor 2 scores over time suggested that 6 years since initiation of ecstasy use might be a time when some long-term users may be open to reassess their use of the drug. Broader implications of the findings for health education initiatives aimed at ecstasy users are discussed.

Reasoning deficits in ecstasy (MDMA) polydrug users.

RATIONALE/OBJECTIVES: Previous research has shown that ecstasy users are impaired in thinking and reasoning. The present study sought to explore the possibility that syllogistic reasoning errors in ecstasy users were due to an inability to construct a model of the premises due to working memory limitations. METHODS: Twenty-nine ecstasy users and 25 nonecstasy user controls completed abstract syllogistic reasoning problems varying in difficulty. Pairs of premises were provided, and participants were required to generate conclusions that followed necessarily from them. RESULTS: On the easier problems, both groups performed at well above chance although nonusers achieved significantly more correct responses. Consistent with existing research, on the more difficult problems, errors by nonusers were characterised by incorrect conclusions suggesting that while nonusers have the working memory capacity to construct a single model of the premises, this is not an exhaustive representation and usually results in an erroneous conclusion. On the other hand, for all problem types, ecstasy users, rather than produce incorrect responses, were more likely to fail to generate a conclusion. CONCLUSIONS: The present results are consistent with the possibility that ecstasy users with their reduced working memory capacity may experience difficulty in constructing even a single model of the premises. While this might be attributable to the effects of 3,4-methlylenedioxymethamphetamine neurotoxicity, many of the ecstasy users in the present study were polydrug users. Thus, the possibility that other drugs including cannabis and cocaine might contribute to the present results cannot be excluded.

Syllogistic reasoning performance in MDMA (Ecstasy) users.

Previous research has demonstrated working memory and executive deficits in recreational users of MDMA (3,4-methylenedioxymethamphetamine; Ecstasy). In turn, both of these constructs have been implicated in syllogistic reasoning performance. Twenty-two MDMA users (mean age = 21.36) and 26 MDMA nonuser controls (mean age = 21.31) were tested on syllogisms of varying difficulty and on measures of working memory and executive functioning. MDMA users were significantly impaired in aspects of syllogistic reasoning, and the effect remained significant after the authors controlled for the use of other drugs. However, the MDMA-related variance was reduced to below statistical significance following control for group differences in working memory span. The results are consistent with the possibility that MDMA-related deficits in aspects of executive functioning result in impaired reasoning performance among MDMA users.

Visuo-spatial working memory deficits in current and former users of MDMA ('ecstasy').

Verbal working memory and executive deficits have been observed in ecstasy users. The present study sought to establish whether these also extended to visuo-spatial working memory. Thirty-six current ecstasy users, 12 former users (abstinent for at least 6 months) and 31 individuals that had never used ecstasy were tested on a maintenance plus type visuo-spatial working memory task. The task required participants to recall a sequence of specially marked cells in a four-by-four matrix display while at the same time performing a concurrent visual judgement task. Both the current and former user groups registered impairments relative to nonusers. These remained significant following statistical controls for a range of potentially confounding variables including the use of various other drugs during the 3 months prior to testing. Users were unimpaired on a simple spatial span measure suggesting that the deficits observed reflected the executive aspects of the spatial working memory task. Also consistent with executive involvement, statistical controls for measures of verbal working memory performance (computation span) removed half of the ecstasy-related variance in spatial working memory. The possibility that the pattern of results obtained might reflect some general impairment in information processing efficiency is discussed.

Evidence for executive deficits among users of MDMA (Ecstasy).

Random letter generation and computation span are tasks known to load on executive, prefrontal resources. Previous research suggests that Ecstasy users are impaired on random letter generation. The current study, employing a larger sample (44 current Ecstasy users, and 59 non-Ecstasy users), together with more effective statistical controls for other drug use, failed to replicate previous findings. Ecstasy users were unimpaired on all measures of random generation performance. A significant difference was obtained on the computation span measure, with Ecstasy users scoring significantly lower than non-Ecstasy users. This difference remained statistically significant following control for various indicators of the use of other drugs including cannabis. The results are discussed in terms of the potential effects that Ecstasy might have on different component executive processes.

Verbal working memory deficits in current and previous users of MDMA.

Previous research suggests that MDMA users are impaired in various aspects of cognitive functioning, however, it remains unclear whether they might experience deficits in established measures of verbal working memory functioning. In the present study current and previous MDMA users were compared with non-users on verbal working memory measures including reading and computation span. Both user groups were found to be impaired on the computation span measure while current users also exhibited impairment in reading span. The MDMA-related deficit on the computation span measure remained significant following the introduction of statistical controls for the potentially confounding effects of cannabis and other drugs. The results are discussed in the context of recent research on executive processes. It is suggested that MDMA may produce differential effects on specific components within a fractionated executive system.

Visuospatial memory impairments in users of MDMA ('ecstasy').

RATIONALE: Previous studies have presented conflicting findings regarding visuospatial span deficits in MDMA ('ecstasy') users, possibly attributable to a lack of distinction between simple visuospatial span and visuospatial working memory span. Both draw upon central executive processing, while the latter also involves concurrent goal-orientated visuospatial processing. OBJECTIVES: This study compared visuospatial working memory span for MDMA users and controls. An additional concurrent task also loading on the central executive tested for inter-group differences related to central executive workload. METHOD: MDMA user group (25 current users, 10 previous users and 18 non-users) was between-participants, and dual task condition (concurrent alphabetic generation, random letter generation, and no dual task) was within-participants. The visuospatial working memory task required participants to serially recall a spatial sequence while simultaneously completing a visual judgement task, and was completed on its own and under dual task conditions. RESULTS: Overall, non-users performed significantly better than both MDMA user groups. However, contrary to expectation, the performance decrement among users was no worse with concurrent random generation than under control conditions. Analyses controlling for background variables and the use of other drugs in the previous 3 months showed that the main effect of MDMA remained significant following control for intelligence, alcohol, amphetamines and cocaine, among other potential confounds. Unclear results were found following control for cannabis use. CONCLUSIONS: The MDMA users experienced deficits in visuospatial working memory span. The lack of interaction between dual task condition and user group may be due to inter-group differences in central executive utilisation under different task conditions.