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

Prospective memory deficits in illicit polydrug users are associated with the average long term typical dose of ecstasy typically consumed in a single session

Rationale Neuroimaging evidence suggests that ecstasy-related reductions in SERT densities relate more closely to the number of tablets typically consumed per session rather than estimated total lifetime use. In order to better understand the basis of drug related deficits in prospective memory (PM) we explored the association between PM and average long-term typical dose and long-term frequency of use. Method Study 1: Sixty five ecstasy/polydrug users and 85 non-ecstasy users completed an event based, a short-term and a long-term time based PM task. Study 2: Study 1 data were merged with outcomes on the same PM measures from a previous study creating a combined sample of 103 ecstasy/polydrug users, 38 cannabis-only users and 65 nonusers of illicit drugs. Results Study 1: Ecstasy/polydrug users had significant impairments on all PM outcomes compared to non-ecstasy users. Study 2: Ecstasy/polydrug users were impaired in event based PM compared to both other groups and in long-term time based PM compared to non illicit drug users. Both drug using groups did worse on the short-term time based PM task compared to nonusers. Higher long-term average typical dose of ecstasy was associated with poorer performance on the event and short-term time based PM tasks and accounted for unique variance in the two PM measures over and above the variance associated with cannabis and cocaine use. Conclusions The typical ecstasy dose consumed in a single session is an important predictor of PM impairments with higher doses reflecting increasing tolerance giving rise to greater PM impairment

Effects of media representations of drug related deaths on public stigma and support for harm reduction

Background Drug related deaths (DRD) are at historically high levels in the United Kingdom (UK), but some approaches that have the potential to reduce risk of mortality remain controversial. Public support makes an important contribution to drug policy development but there are high levels of public stigma towards people who use drugs (PWUD), and this is partly shaped by media representations. We investigated whether depiction of the characteristics of decedents represented in news articles about DRD was associated with differences in stigmatising attitudes and support for harm reduction policy. Methods We undertook a cross-sectional online study with a randomised design, conducted with a nationally representative sample (UK). Participants (N = 1280) were randomly presented with one of eight simulated news stories that reported on a DRD that differed with respect to drug (ecstasy or heroin), and the gender (male or female) and age (younger or older) of the decedent. Data were analysed using MANOVA. Results Data were obtained for 1248 participants (51.0% female; mean age 45.7±15.4). Stigma was higher towards depictions of male, older, and heroin deaths (all p < .001). Harm reduction support was higher in those participants seeing older compared to younger subjects (p = .035), and the older ecstasy decedent compared to younger decedent (p = .029). Conclusion Presentation of some types of DRD are associated with higher public stigma towards the decedent than others. Those groups developing agenda-setting activities designed to reduce stigma or foster public support for harm reduction policies should consider the different ways in which audiences may respond to the depiction and framing of DRD in news media

Assessing the functional significance of ecstasy-related memory deficits using a virtual paradigm

Rationale/Objectives: Previous research shows that the use of ecstasy results in working memory and executive impairments in some users. The present study sought to assess the functional significance of such deficits using a virtual reality task. Methods: Twenty-three ecstasy-polydrug users and 26 nonusers were recruited. Individuals completed a drug use questionnaire measures of sleep quality and fluid intelligence. Participants also completed a virtual reality executive function task in which they play the role of an office worker for the day completing predefined tasks such as prioritising different activities according to their importance, organising the physical office environment and managing the outgoing mail in accordance with a delivery schedule. Results: MANOVA revealed that ecstasy users performed worse on the virtual reality task overall, and this was due to poorer performance on the planning and selection subscales. Contrary to expectations, ecstasy-polydrug users performed better on the time-based prospective memory subscale. Indices of ecstasy use were correlated with the planning subscale of the virtual task. Conclusions: The present study provides further support for ecstasy/polydrug related deficits in executive functioning. As it is possible that this task is more ecologically valid and relevant to day-to-day activities of many users, previous research finding null results on executive function tasks may have underestimated the impact of ecstasy-polydrug use on executive functioning

Effects of ecstasy/polydrug use on memory for associative information

Rationale Associative learning underpins behaviours that are fundamental to the everyday functioning of the individual. Evidence pointing to learning deficits in recreational drug users merits further examination. Objectives A word pair learning task was administered to examine associative learning processes in ecstasy/polydrug users. Methods After assignment to either single or divided attention conditions, 44 ecstasy/polydrug users and 48 non-users were presented with 80 word pairs at encoding. Following this, four types of stimuli were presented at the recognition phase: the words as originally paired (old pairs), previously presented words in different pairings (conjunction pairs), old words paired with new words, and pairs of new words (not presented previously). The task was to identify which of the stimuli were intact old pairs. Results Ecstasy/ploydrug users produced significantly more false-positive responses overall compared to non-users. Increased long-term frequency of ecstasy use was positively associated with the propensity to produce false-positive responses. It was also associated with a more liberal signal detection theory decision criterion value. Measures of long term and recent cannabis use were also associated with these same word pair learning outcome measures. Conjunction word pairs, irrespective of drug use, generated the highest level of false-positive responses and significantly more false-positive responses were made in the divided attention condition compared to the single attention condition. Conclusions Overall, the results suggest that long-term ecstasy exposure may induce a deficit in associative learning and this may be in part a consequence of users adopting a more liberal decision criterion value

Prospective memory functioning among ecstasy/polydrug users: evidence from the Cambridge Prospective Memory Test (CAMPROMPT)

Rationale: Prospective memory (PM) deficits in recreational drug users have been documented in recent years. However, the assessment of PM has largely been restricted to self-reported measures that fail to capture the distinction between event-based and time-based PM. The aim of the present study is to address this limitation. Objectives: Extending our previous research, we augmented the range laboratory measures of PM by employing the CAMPROMPT test battery to investigate the impact of illicit drug use on prospective remembering in a sample of cannabis only, ecstasy/polydrug and non-users of illicit drugs, separating event and time-based PM performance. We also administered measures of executive function and retrospective memory in order to establish whether ecstasy/polydrug deficits in PM were mediated by group differences in these processes. Results: Ecstasy/polydrug users performed significantly worse on both event and time-based prospective memory tasks in comparison to both cannabis only and non-user groups. Furthermore, it was found that across the whole sample, better retrospective memory and executive functioning was associated with superior PM performance. Nevertheless, this association did not mediate the drug-related effects that were observed. Consistent with our previous study, recreational use of cocaine was linked to PM deficits. Conclusions: PM deficits have again been found among ecstasy/polydrug users, which appear to be unrelated to group differences in executive function and retrospective memory. However, the possibility that these are attributable to cocaine use cannot be excluded

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

Background. 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. Methods. One hundred and five participants (mean age 21.33, S.D. 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 (NVC). 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. Results. The number of valid common inferences was negatively associated with 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. Conclusions. 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

Meta-analysis of molecular imaging of serotonin transporters in ecstasy/polydrug users

We conducted a meta-analysis on the available data from studies investigating SERTs in ecstasy users and polydrug using controls. From 7 studies we compared data from 157 ecstasy users and 148 controls across 14 brain regions. The main effect suggested ecstasy/MDMA related SERT reductions (SMD = 0.52, 95% CIs [0.40, 0.65]; Z = 8.36, p < .01, I2 = 89%). A significant effect of subgroups (X2 = 37.41, df = 13, p < .01, I2 = 65.3%) suggested differential effects across brain ROIs. Ecstasy users showed significant SERT reductions in 11 out of the 14 regions, including every neocortical and limbic region analysed. Greatest effects were observed in the occipital cortex (SMD = 1.09, 95% CIs [0.70, 1.48]). No group effects were observed in subcortical areas of the caudate, putamen and midbrain. Literature on Postsynaptic 5HT2A receptor imaging was synthesised with these results. We conclude that, in line with preclinical data, serotonin axons with the longest projections from the raphe nuclei appear to be most affected by ecstasy/MDMA use