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

Abstract

Edge Hill College of Higher EducationRunning head: concurrent cannabis use among ecstasy users. 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.There is abundant evidence that ecstasy (MDMA) is neurotoxic, disrupting serotonergic systems in diverse brain regions. There is also a considerable body of evidence that cannabis can have neuroprotective as well as neurotoxic properties.Given that most ecstasy users are also cannabis users (Morgan, 2000) the question arises as to whether concurrent use of cannabis by ecstasy users might make them less susceptible to MDMA related neurotoxicity. The present paper is intended to investigate this issue.Although there is abundant evidence that MDMA is neurotoxic in a range of animal species, evidence of neurotoxicity in humans is less extensive and sometimes controversial (Curran, 2000). A review of the neuroimaging evidence can be found in Reneman et al (2006). A number of studies have found evidence of neurotoxicity among ecstasy users. For example, using PET neuroimaging, McCann, et al (1998), investigated 5-HT neural damage in the brains of ecstasy users. Regions of interest included the frontal cortex, pariental cortex, temporal cortex, occipital cortex and cingulate cortex, as well as the caudate, putamen, thalamus, mid-brain, pons, hypothalamus and cerebellum. The results showed that, compared to a control group, ecstasy users had significantly lower densities of 5HT transporter sites in all brain regions. Further, the reductions observed were correlated with the extent of ecstasy use. Reneman, et al (2002a) also assessed neural injury in ecstasy users using single-voxel (1H) MR spectroscopy imagining. N-Acetylasportate (NAA)/Creatine (CR), NAA Choline (CHO), and Myoinositol (MI) CR ratios in ecstasy users were meas...

Is moderate substance use associated with altered executive functioning in a population‐based sample of young adults?

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Investigating the Role of Serotonin in Visual Orientation Processing Using an ‘Ecstasy’ (MDMA)-Based Research Model

“…Thus, the findings of the current study are not consistent with the premise that cannabis, when used concomitantly with ecstasy protects against the neurotoxic effects of ecstasy on the serotonin axons, at least of sufficient magnitude to be identified within the current method. Independent studies have similarly failed to identify neuroprotective effects of concomitant cannabis use on behavioural measures in humans [37] .…”

Modelling the Adverse Effects Associated With Ecstasy (MDMA) Usage

“…The lack of relationship between awareness of ecstasy's effects and the total of adverse effects reported does not support the assertion that users' reports of such effects may be magnified in any substantial way by media and other influences [6]. The concurrent use of alcohol, rather than cannabis, with ecstasy may be an important area for future research [4].…”

“…However, such findings are potentially subject to distorting influences such as the effects of other drugs used concurrently with ecstasy [4], sleep disturbance [5], and external influences such as media reports of ecstasy related harm which may increase users' propensity to attribute adverse effects to their use of the drug [6]. Statistical analysis of self-reported adverse effects can also be difficult due to distribution problems arising from a large number of zero scores for particular effects [3].…”