Ecstasy exposure & gender: examining components of verbal memory functioning

Gender disparities in neuropsychological assessment research in drug abuse populations: A systematic review

Objective: To systematically review the literature on the neurocognitive effects of drug use to determine if there are significant gender differences. Methods: In April 2023, we conducted a broad search in MEDLINE (via PubMed), PsycINFO, and Embase for original research studies that used objective neuropsychological assessment to evaluate neurocognition in persons with drug use. Data extraction was performed in a masked, duplicate fashion. Results: Our initial search returned 22,430 records, of which 273 articles were included in our analysis. We found significant underrepresentation of women as participants in the studies. Twenty-one percent of studies had exclusively male participants; when women were included, they averaged only 23% of the sample. Only 49 studies sufficiently documented an analysis of their results by gender; due to the heterogeneity in study characteristics, no conclusions about cognitive differences between women and men could be made. Conclusions: Women are significantly underrepresented in the research on cognition in drug use. Increased efforts to include more women participants and consistent analysis and reporting of data for potential gender differences will be required to close this gap in knowledge, which may lead to improved substance abuse treatment approaches for women.

Neurotoxicity of MDMA: Main effects and mechanisms

Preclinical and clinical studies indicate that 3,4-methylenedioxymethamphetamine (MDMA; 'ecstasy'), in addition to having abuse potential, may elicit acute and persistent abnormalities of varying severity at the central level. Importantly, neurotoxic effects of MDMA have been demonstrated in experimental animals. Accordingly, central toxicity induced by MDMA may pose a serious harm for health, since MDMA is among the substances that are used for recreational purposes by young and adult people. This review provides a concise overview of recent findings from preclinical and clinical studies that evaluated the central effects of MDMA, and the mechanisms involved in the neurotoxicity induced by this amphetamine-related drug.

Neurological and cognitive alterations induced by MDMA in humans

3,4 Methylenedioxymethamphetamine generally referred to as MDMA or 'ecstasy' is a ring-substituted phenethylamine stimulant which produces powerful empathogenic effects. Use of MDMA remains popular despite prohibition, and potential long-term negative consequences of repeated use. MDMA produces its acute subjective effects primarily by stimulating the release of serotonin via action at the serotonin transporter (SERT). There is evidence that MDMA administration may lead to long lasting neurotoxic effects on serotonin neurons in primates, and reductions in markers of central serotonin axons, and axon terminals in animals. In humans, demonstration of serotonergic neurotoxicity is much more difficult to identify, and much of the research is complicated by confounding issues of polysubstance use, genetic and environmental factors and reliance on self-reports of previous drug use. We do not review the mechanisms for neurotoxicity in detail as they are covered elsewhere in this special issue. There is a large body of literature, however, which has investigated potential cognitive and neurocognitive consequences of repeated MDMA use. Here we review the literature on cognition, and neuroimaging studies that have investigated structural and functional brain changes associated with ecstasy use.

Activation of Antioxidant and Proteolytic Pathways in the Nigrostriatal Dopaminergic System After 3,4-Methylenedioxymethamphetamine Administration: Sex-Related Differences

3,4-Methylenedioxymethamphetamine (MDMA, “ecstasy”) is an amphetamine-related drug that may damage the dopaminergic nigrostriatal system. To investigate the mechanisms that sustain this toxic effect and ascertain their sex-dependence, we evaluated in the nigrostriatal system of MDMA-treated (4 × 20 mg/kg, 2 h apart) male and female mice the activity of superoxide dismutase (SOD), the gene expression of SOD type 1 and 2, together with SOD1/2 co-localization with tyrosine hydroxylase (TH)-positive neurons. In the same mice and brain areas, activity of glutathione peroxidase (GPx) and of β2/β5 subunits of the ubiquitin-proteasome system (UPS) were also evaluated. After MDMA, SOD1 increased in striatal TH-positive terminals, but not nigral neurons, of males and females, while SOD2 increased in striatal TH-positive terminals and nigral neurons of males only. Moreover, after MDMA, SOD1 gene expression increased in the midbrain of males and females, whereas SOD2 increased only in males. Finally, MDMA increased the SOD activity in the midbrain of females, without affecting GPx activity, decreased the β2/β5 activities in the striatum of males and the β2 activity in the midbrain of females. These results suggest that the mechanisms of MDMA-induced neurotoxic effects are sex-dependent and dopaminergic neurons of males could be more sensitive to SOD2- and UPS-mediated toxic effects.

Adolescent brain cognitive development (ABCD) study: Overview of substance use assessment methods

One of the objectives of the Adolescent Brain Cognitive Development (ABCD) Study (https://abcdstudy.org/) is to establish a national longitudinal cohort of 9 and 10 year olds that will be followed for 10 years in order to prospectively study the risk and protective factors influencing substance use and its consequences, examine the impact of substance use on neurocognitive, health and psychosocial outcomes, and to understand the relationship between substance use and psychopathology. This article provides an overview of the ABCD Study Substance Use Workgroup, provides the goals for the workgroup, rationale for the substance use battery, and includes details on the substance use module methods and measurement tools used during baseline, 6-month and 1-year follow-up assessment time-points. Prospective, longitudinal assessment of these substance use domains over a period of ten years in a nationwide sample of youth presents an unprecedented opportunity to further understand the timing and interactive relationships between substance use and neurocognitive, health, and psychopathology outcomes in youth living in the United States.

5-HTTLPR Genotype Moderates the Effects of Past Ecstasy Use on Verbal Memory Performance in Adolescent and Emerging Adults: A Pilot Study

OBJECTIVE

Ecstasy use is associated with memory deficits. Serotonin transporter gene (5-HTTLPR) polymorphisms have been linked with memory function in healthy samples. The present pilot study investigated the influence of 5-HTTLPR polymorphisms on memory performance in ecstasy users, marijuana-using controls, and non-drug-using controls, after a minimum of 7 days of abstinence.

METHOD

Data were collected from 116 young adults (18-25 years-old), including 45 controls, 42 marijuana users, and 29 ecstasy users, and were balanced for 5-HTTLPR genotype. Participants were abstinent seven days prior to completing memory testing. Three MANCOVAs and one ANCOVA were run to examine whether drug group, 5-HTTLPR genotype, and their interactions predicted verbal and visual memory after controlling for gender, past year alcohol use, other drug use, and nicotine cotinine levels.

RESULTS

MANCOVA and ANCOVA analysis revealed a significant interaction between drug group and genotype (p = .03) such that ecstasy users with the L/L genotype performed significantly worse on CVLT-2 total recall (p = .05), short (p = .008) and long delay free recall (p = .01), and recognition (p = .006), with the reverse pattern found in controls. Ecstasy did not significantly predict visual memory. 5-HTTLPR genotype significantly predicted memory for faces (p = .02); short allele carriers performed better than those with L/L genotype.

CONCLUSIONS

5-HTTLPR genotype moderated the effects of ecstasy on verbal memory, with L/L carriers performing worse compared to controls. Future research should continue to examine individual differences in ecstasy's impact on neurocognitive performance as well as relationships with neuronal structure. Additional screening and prevention efforts focused on adolescents and emerging adults are necessary to prevent ecstasy consumption.