The effect of ecstasy/polydrug use on prospective memory and executive processes

The purpose of this thesis was to examine the range of prospective memory and executive function deficits in ecstasy/polydrug users and the role of these processes in accounting for the observed prospective memory performance deficits. Using a variety of laboratory and self-report measures of prospective memory and a self-report measure of executive function, ecstasy/polydrug users were tested in laboratory settings on measures of event and time-based, short and long term prospective memory as well as on a wide range of executive function components. It was found that ecstasy/polydrug users in relation to non-users experience more general prospective memory problems as ecstasy/polydrug-related deficits were evident on both time and event-based and short and long-term prospective memory. Ecstasy/polydrug users also demonstrated deficits on executive processes suggesting that recreational drug users are impaired in a broader range of executive function and ecstasy/polydrug-related deficits are not restricted to the three-model component of executive function. It was also found that executive dysfunction is associated with poorer time-based prospective memory and perhaps some of the drug related prospective memory deficits are mediated by drug related executive function impairment. Finally, although few prospective memory or executive function performance deficits were evident among cannabis-only users a trend was evident in all investigations; ecstasy/polydrug users perform the worst, cannabis-only users at intermediate levels and drug-naïve perform the best. The most striking finding of the present thesis was that the recreational use of cocaine was associated with PM deficits; an association that consistently emerged in all studies of PM performance. The outcomes of the present thesis provide a fruitful direction for future research

The effect of ecstasy/polydrug use on prospective memory and executive processes

The purpose of this thesis was to examine the range of prospective memory and executive function deficits in ecstasy/polydrug users and the role of these processes in accounting for the observed prospective memory performance deficits. Using a variety of laboratory and self-report measures of prospective memory and a self-report measure of executive function, ecstasy/polydrug users were tested in laboratory settings on measures of event and time-based, short and long term prospective memory as well as on a wide range of executive function components. It was found that ecstasy/polydrug users in relation to non-users experience more general prospective memory problems as ecstasy/polydrug-related deficits were evident on both time and event-based and short and long-term prospective memory. Ecstasy/polydrug users also demonstrated deficits on executive processes suggesting that recreational drug users are impaired in a broader range of executive function and ecstasy/polydrug-related deficits are not restricted to the three-model component of executive function. It was also found that executive dysfunction is associated with poorer time-based prospective memory and perhaps some of the drug related prospective memory deficits are mediated by drug related executive function impairment. Finally, although few prospective memory or executive function performance deficits were evident among cannabis-only users a trend was evident in all investigations; ecstasy/polydrug users perform the worst, cannabis-only users at intermediate levels and drug-naïve perform the best. The most striking finding of the present thesis was that the recreational use of cocaine was associated with PM deficits; an association that consistently emerged in all studies of PM performance. The outcomes of the present thesis provide a fruitful direction for future research.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

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

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

Prospective memory functioning among ecstasy/polydrug users: evidence from the Cambridge Prospective Memory Test (CAMPROMPT). Psychopharmacology 25

Abstract 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 selfreported 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