Concurrent use of methamphetamine, MDMA, LSD, ketamine, GHB, and flunitrazepam among American youths

Green Analytical Toxicology procedure for determination of ketamine, its metabolites and analogues in oral fluid samples using dispersive liquid-liquid microextraction (DLLME)

New psychoactive substances (NPS) are often synthesized via small changes in the molecular structure, producing drugs whose effect and potency are not yet fully known. Ketamine is one of the oldest NPS, with therapeutic use in human and veterinary medicine authorized in several countries, being metabolized mainly into norketamine and 6-hydroxy-norketamine. Furthermore, two structural analogues of ketamine have recently been identified, deschloroketamine and 2-fluorodeschloroketamine, marketed as drugs of abuse. To comply with Green Analytical Toxicology (GAT) fundamentals, miniaturized techniques such as dispersive liquid-liquid microextraction (DLLME) were employed to determine toxicants in biological fluids. An analytical method for determining ketamine, its metabolites and its analogues in oral fluid was fully developed and validated by using DLLME and liquid chromatography-tandem mass spectrometry (LC-MS-MS). The extraction parameters were optimized by multivariate analysis, obtaining the best conditions with 200 μL of sample, 100 μL of methanol as dispersive solvent and 50 μL of chloroform as extractor solvent. Linearity was obtained from 10 to 1,000 ng/mL, with limit of detection (LOD) and lower limit of quantification (LLOQ) at 10 ng/mL. Imprecision (% relative standard deviation) and bias (%) were less than 8.2% and 9.5%, respectively. The matrix effect did not exceed 10.6%, and the recovery values varied from 24% to 42%. No matrix interference and good selectivity in the evaluation of 10 different sources of oral fluid and 42 drugs at 500 ng/mL, respectively, were observed. The method was applied in the analysis of 29 authentic oral fluid samples and had its green characteristic evaluated by three different tools: the Green Analytical Procedure Index (GAPI), the Analytical Eco-Scale and the Analytical GREEnness (AGREE) metrics.

Identifying the Factors Affecting Methamphetamine Use: A Scoping Review

Background

One of the critical factors affecting chronic diseases is the use of drugs, especially industrial substances, such as methamphetamine. Methamphetamine use is increasingly common among the younger members of society. Methamphetamine is not only physically and mentally destructive, but also has a significant impact on the families of abusers and society, and imposes a financial burden on society. The present study aims to identify the factors affecting methamphetamine use in a scoping review.

Methods

Different keywords of methamphetamine were selected in the Mesh database and were searched in valid English databases from January 1, 2008, to April 5, 2022. Inclusion and exclusion criteria in this study were languages, reported findings, time range, and type of article. This study was designed by scoping review method developed by Askey Malley'O.

Results

The total articles that were finally analyzed in this article were 42 including 12 English articles and 30 Persian articles. Among these articles, the most important factors affecting Methamphetamine are individual, social, and family factors, which have received the most cited.

Conclusion

The majority of research highlights the importance of individual factors, society, and family factors, respectively, while formulating policies for prevention, treatment, and rehabilitation must be considered. It is suggested that structural path analysis be determined by prioritizing the identified factors and the weights of these components.

Prevalence of psilocybin use in vaping and associated factors: a study among amphetamine-type stimulants (ATS) use disorder in Malaysia

BACKGROUND

The emergence of New Psychoactive Substances (NPS), including synthetic psilocybin, has raised concern among health experts due to the numerous health and socioeconomic consequences. The current trend is shifting to the hazardous use of synthetic psilocybin in vaping, and little is known about the prevalence of use, specifically among amphetamine-type stimulants (ATS) users.

METHODS

Interviewer-administered questionnaires were conducted in drug detention centers between March and October 2022. The study was conducted using ASSIST 3.0 and obtained information on the respondents' socio-demographic characteristics and clinical profiles. N = 355 ATS users were enrolled in this study.

RESULTS

The results show a high prevalence of psilocybin vaping among ATS users (182/355, 53.1%). Most of the respondents were males (85.1%) and unmarried (69.3%), with a mean age of 29.2 (SD = 7.3). Across all respondents, five factors were associated with psilocybin vaping: tobacco smoking, aOR =5.790 (95% CI: 1.723, 8.183); cannabis uses, aOR= 9.152 (95% CI: 2.693, 10.396); and alcohol use, aOR= 3.137 (95% CI: 1.461, 5.817). Respondents of the Malay race had higher odds of being involved in psilocybin vaping compared to other races, with aOR= 1.638 (0.043, 2.459). Meanwhile, a reduction in age by 1.9 will increase the likelihood of involvement in psilocybin vaping with aOR = 1.897 (95% CI: 0.857, 1.938).

CONCLUSION

Psilocybin in vaping is growing among ATS users and across all populations. Unfortunately, knowledge regarding the long-term effects on health is limited. Further studies should highlight the harmful effects of psilocybin and the potential risk of psilocybin vaping among the younger population.

A Scientometric Visualization Analysis for Molecular Mechanisms of Substance Abuse and Its Neurotoxicity From 1997 to 2021

Substance abuse has become a global problem due to drug-induced addiction and neurotoxicity, which causes a huge physical, social, and financial burden. Various kinds of drugs can hijack the users’/abusers’ behavior and associated neurocircuitry. To summarize recent scientific advances on drug abuse, we reviewed relevant publications to analyze research progress and such trends through bibliometric ways. Based on retrieval strategies, a total of 681 scientific records published from 1997 to 2021 were screened and included in the Web of Science (WoS) database. Further scientometric analysis revealed that annual publication output increased across this period, with the United States of America (USA) contributing a significant number of reasons. Research has focused on neurotransmitter, oxidative stress, mitochondrial system injury, and other neurotoxic mechanisms. Neuroimmune, neurotoxic targets, and new psychoactive substances have been hot topics in recent years, which deserve continued research in the future. Specific research on molecular mechanisms has progressed across this period, with an emphasis on the root cause of toxicity and molecular targets for therapy. Moreover, collaborations of international multi-disciplinary research teams have been efficient and need to be encouraged for addiction research and the development of appropriate therapeutic processes.

The Changing Patterns and Correlates of Adolescent Substance Use in China's Special Administrative Region of Macau

Most of the research on adolescent substance use is from either the U.S, Europe, or other non-Eastern countries, but very little attention is paid to that in the Greater China Region. As a special administrative region of China, Macau is known for its gambling industry, its proximity to the Golden Triangle, and its lenient drug laws, all of which can be conducive to high-level drug use in the population, including its adolescents. Yet, the extent and patterns of adolescent substance use in Macau are not well understood. Using the data collected from two large representative samples of secondary school students in 2014 and 2018, this study provided population-based estimates of the prevalence rates of lifetime and past 30-day substance use among Macau adolescents in the two separate survey years. By comparing the two sets of estimates, it established the patterns of changes in cigarette smoking, alcohol use, and illicit drug use among adolescents in Macau during the period. Additionally, through the analysis of the data in the latest year, it identified risk factors for adolescent substance use in the special administrative region. Among the key results, the rates of cigarette smoking and illicit drug use were low to moderate while the rates of alcohol use were relatively high; cigarette smoking decreased during the period, but alcohol use and illicit drug use remained stable; Macau adolescents shared similar risk factors for substance use with adolescents elsewhere, but unique circumstances might exist to influence their alcohol consumption.

Toward a typology of hallucinogen users in the United States

BACKGROUND

Roughly one in ten American adults have used hallucinogens, and emerging evidence suggests that the prevalence of use is increasing. However, our understanding of the degree to which individuals "specialize" in the use of a particular hallucinogen or are poly-hallucinogen users remains incomplete.

METHODS

This study examined data from 6381 individuals reporting past-year hallucinogen use in the 2016-2018 National Survey on Drug Use and Health. Logistic regression examined the association between the number of distinct hallucinogens used and psychosocial/behavioral risks, and latent class analysis (LCA) characterized subgroups of hallucinogen users.

RESULTS

The vast majority of hallucinogen users, roughly 70%, are not "specialists" who use only one hallucinogen type; rather, lifetime poly-hallucinogen use is the norm. Critically, however, we also see that important differences exist within the population of hallucinogen users-half (51%) could be classified as LSD-Mushroom-Ecstasy users only (this group was disproportionally comprised of youth), nearly one third (30%) were Poly-Hallucinogen users (this group was disproportionately male and non-Hispanic White), and smaller proportions were limited primarily to use of LSD-Mushrooms (6%; these individuals were almost exclusively ages 35 and older) or Ecstasy Only (12%; these individuals were mostly younger adults ages 18-34).

CONCLUSIONS

Findings provide a fresh contribution to our understanding of poly-hallucinogen use in a time in which local and state governmental leaders, and people across the country, weigh the benefits and drawbacks of legalizing specific hallucinogenic drugs.

Use and abuse of dissociative and psychedelic drugs in adolescence

Adolescence is a period of profound developmental changes, which run the gamut from behavioral and neural to physiological and hormonal. It is also a time at which there is an increased propensity to engage in risk-taking and impulsive behaviors like drug use. This review examines the human and preclinical literature on adolescent drug use and its consequences, with a focus on dissociatives (PCP, ketamine, DXM), classic psychedelics (LSD, psilocybin), and MDMA. It is the case for all the substances reviewed here that very little is known about their effects in adolescent populations. An emerging aspect of the literature is that dissociatives and MDMA produce mixed reinforcing and aversive effects and that the balance between reinforcement and aversion may differ between adolescents and adults, with consequences for drug use and addiction. However, many studies have failed to directly compare adults and adolescents, which precludes definitive conclusions about these consequences. Other important areas that are largely unexplored are sex differences during adolescence and the long-term consequences of adolescent use of these substances. We provide suggestions for future work to address the gaps we identified in the literature. Given the widespread use of these drugs among adolescent users, and the potential for therapeutic use, this work will be crucial to understanding abuse potential and consequences of use in this developmental stage.

Reliability of a Rapid Screener for an Intercept Survey about Drug Use

Intercept surveys are a relatively inexpensive method to rapidly collect data on drug use. However, querying use of dozens of drugs can be time-consuming. We determined whether using a rapid screener is efficacious in detecting which participants use drugs and should be offered a full survey which asks more extensively about use. We surveyed 103 adults (age 18-29) on streets of Manhattan, NY in 2019 to test the reliability of a screener which queried past-year use of six drugs. Those reporting any drug use on the screener (and a third of those not reporting drug use) were offered the full survey which queried use of 97 drugs. We compared self-reported use on the screener to the full survey. Self-reported use of ecstasy, cocaine, and LSD had high test-retest reliability (Kappa = 0.90-1.00), and the screener had high sensitivity (1.00) and specificity (0.97-1.00) in detecting use of these drugs. Reliability for marijuana (Kappa = 0.62) and nonmedical opioid use (Kappa = 0.75) was lower. The screener had higher sensitivity (0.94) and lower specificity (0.64) in detecting marijuana use, and lower sensitivity (0.71) and higher specificity (0.98) in detecting nonmedical opioid use. Within the full survey, all participants reporting use of amphetamine (nonmedical use), shrooms, poppers, synthetic cannabinoids, synthetic cathinones, novel psychedelics, ketamine, or GHB reported use of at least one drug queried on the screener. Self-reported use of common drugs on a screener can reliably be used as an inclusion criterion for more extensive intercept surveys about drug use behavior.

Neural Mechanisms Underlying the Rewarding and Therapeutic Effects of Ketamine as a Treatment for Alcohol Use Disorder

Alcohol use disorder (AUD) is the most prevalent substance use disorder and causes a significant global burden. Relapse rates remain incredibly high after decades of attempting to develop novel treatment options that have failed to produce increased rates of sobriety. Ketamine has emerged as a potential treatment for AUD following its success as a therapeutic agent for depression, demonstrated by several preclinical studies showing that acute administration reduced alcohol intake in rodents. As such, ketamine's therapeutic effects for AUD are now being investigated in clinical trials with the hope of it being efficacious in prolonging sobriety from alcohol in humans (ClinicalTrials.gov, Identifier: NCT01558063). Importantly, ketamine's antidepressant effects only last for about 1-week and because AUD is a lifelong disorder, repeated treatment regimens would be necessary to maintain sobriety. This raises questions regarding its safety for AUD treatment since ketamine itself has the potential for addiction. Therefore, this review aims to summarize the neuroadaptations related to alcohol's addictive properties as well as ketamine's therapeutic and addictive properties. To do this, the focus will be on reward-related brain regions such as the nucleus accumbens (NAc), dorsal striatum, prefrontal cortex (PFC), hippocampus, and ventral tegmental area (VTA) to understand how acute vs. chronic exposure will alter reward signaling over time. Additionally, evidence from these studies will be summarized in both male and female subjects. Accordingly, this review aims to address the safety of repeated ketamine infusions for the treatment of AUD. Although more work about the safety of ketamine to treat AUD is warranted, we hope this review sheds light on some answers about the safety of repeated ketamine infusions.

Rapid Drop-Volume Electrochemical Detection of the "Date Rape" Drug Flunitrazepam in Spirits Using a Screen-Printed Sensor in a Dry-Reagent Format

Flunitrazepam is an extremely potent benzodiazepine sedative which is associated with "drug-facilitated sexual assault" when administered within an alcoholic drink. This work describes a simple electrochemical method for on-site rapid detection of flunitrazepam in untreated spirits (whiskey, vodka and gin) using a single-use screen-printed sensor (featuring graphite working and auxiliary electrodes and an Ag/AgCl reference electrode) in a dry reagent format. Analysis was performed by placing a drop of sample on the sensor, which was previously coated with dry KCl, and recording selected reduction/oxidation peaks of the target compound in a cyclic voltammetry scan. The limit of quantification of flunitrazepam was at the sub-mg L^-1 range. The between-sensor % relative standard deviation of the analytically useful reduction peak in a solution containing 11.4 mg L^-1 flunitrazepam was 9.8% (n = 5). Quantification was performed using calibration curves constructed from pooled samples spiked with flunitrazepam with relative errors <15%. The main advantages of the methodology are that it involves no sample pretreatment (such as deoxygenation, extraction or reagent(s) addition) and requires only drop-sized volumes of the sample, thus facilitating rapid on-site screening using portable equipment.

Comparing ecstasy users and non-users in a population-based and co-twin control design across multiple traits

OBJECTIVE

Ecstasy is one of the most commonly used illicit substances in Western countries. The aim of this study is to identify characteristics of ecstasy users in a large population-based sample of adults aged 18-45 years.

METHOD

With generalized estimating equation models we explored the association between self-reported lifetime ecstasy use and urbanicity, educational attainment, health, wellbeing, stress, other substance use, personality traits and psychopathology in a Dutch twin sample (N = 9578, 66.8% female, 18-45 years). We also explored the nature of the association (underlying genetic factors, shared environmental factors or a causal relationship) with the co-twin control method.

RESULTS

Lifetime ecstasy users (N = 945, 9.9%) were more often male, younger, living more often in urban areas, higher educated, less satisfied with life and more stressed than non-users. Ecstasy users scored differently on most personality and psychopathology scales compared to non-users and were more likely to have used every other substance we investigated. Whereas smoking tobacco and alcohol use often preceded first use of ecstasy, first ecstasy use often preceded first use of other illicit substances. A combination of scenarios (both causal and environmental/genetic) explained the strong associations between ecstasy and substance use.

CONCLUSIONS

Ecstasy users differ on many characteristics from non-users, and especially on illicit substance use. Our results indicate that causal effects may play a role in explaining the relationship between ecstasy use and other illicit substance use.

Trends in LSD use among US adults: 2015-2018

BACKGROUND

The recent use of LSD to treat severe psychological disorders in several clinical applications has proven effective in reducing symptoms and distressing events. Trend analyses are warranted to provide the most current data for clinical and health interventions. The purpose of this study was to examine trends in LSD use among adults in the United States.

METHODS

A secondary analysis of the 2015-2018 National Survey on Drug Use and Health was conducted on 168, 562 adults ages 18 and older.

RESULTS

Past-year LSD use increased 56.4% (P < .0001) from 2015 to 2018. The proportion of LSD users ages 26-34 increased from 19.6% to 31.1% (P < .0001), ages 35-49 increased from 2.73% to 8.82% (P < .0001) and 50 years or older increased from 1.83% to 2.66% (P < .0001). LSD use among bisexual individuals increased from 11.2% to 13.0% (P < .0001). LSD use among individuals with a college degree or more increased from 18.2% to 31.1% (P < .0001). Significant decreases in LSD use were present in individuals who were multi-racial (P < .0001), less than high school education P < .0001), high school education (P < .001), and perceived great risk of drugs (P < .0001).

CONCLUSIONS

LSD use in the US jumped 56.4% from 2015 to 2018. Results from the present study can inform prevention and harm reduction efforts (e.g., co-morbid substance use interventions, health messaging).

Age of Onset of Methamphetamine Consumption among the Iranian Youth Aged 19-29: A Cross-sectional Study

Background

Around the world, one of the main concerns and risky behaviors among youths is methamphetamine consumption. Since the age of onset of methamphetamine use is decreasing, therefore, it is important to identify the effective factors on the age of onset of methamphetamine consumption. In the present study, factors affecting the age of onset of methamphetamine consumption was studied in Iranian youths aged 19-29 years.

Methods

In this cross-sectional nationwide study, individuals aged 19-29 years were selected through multistage cluster sampling and convenience sampling method from 13 provinces in Iran. People completed the questionnaire pertaining to knowledge, attitude, and history of methamphetamine consumption. In order to investigate the factors effective on the age of onset of methamphetamine consumption, we used the Weibull parametric model for data with doubly censored characteristic.

Findings

3246 people participated in this study, half of whom were men and mostly single (60.3%), university student or graduate (50.2%), and unemployed (58.1%). Nearly 6% of participants have ever used methamphetamine. Mean and standard deviation (SD) of age of onset of methamphetamine use was 20.3 ± 3.3 years. Data analysis indicated that the variables of gender, marital status, education, knowing a methamphetamine consumer, knowing an ecstasy consumer, ecstasy consumption, illegitimate sex, attitude towards methamphetamine, and age group were the factors affecting the age of onset of methamphetamine consumption.

Conclusion

The results can contribute to the policy-makers to take the necessary interventions on the factors affecting the age of onset of methamphetamine consumption to reduce the methamphetamine consumption, especially in the critical young ages.

Lab-on-a-screen-printed electrochemical cell for drop-volume voltammetric screening of flunitrazepam in untreated, undiluted alcoholic and soft drinks

Flunitrazepam, also known as "Rohypnol" or "Rophy" among other trade and street names, is an extremely potent benzodiazepine that is prescribed to treat severe insomnia. Due to these attributes, flunitrazepam, when is surreptitiously administered to an alcoholic or soft drink, is associated with "drug-facilitated sexual assault". We report here for the first time, a low cost lab-on-a-screen-printed electrochemical cell (SPC) based on iron-sparked graphite working electrode modified with glucose oxidase (GOx) and glucose hydrogel droplets (GluHD) for the detection of flunitrazepam. Iron-spark modification increases the response of the sensor by ca. 3-fold compared with that of the plain electrode, while an in situ deoxygenation process, based on GOx-glucose enzyme reaction, depletes dissolved oxygen. As a result, the method enables interference free voltammetric measurements of the electro reduction of the nitro group of flunitrazepam at ca. -0.71 to -0.78 V vs. Ag printed pseudo reference electrode depending on the sample's matrix, and the detection of the drug at the sub-millimolar level. GOx/GluHD-FeSPC was directly applied to the drop-volume (∼60 μL) detection of flunitrazepam to a wide range of untreated and undiluted spiked samples (Pepsi cola®, Vodka, Whisky, Tequila, Gin, and Rum) of different acidity (pH 2.3-8.4), and alcohol content up to 40% v/v. Data demonstrate the excellent performance of the sensor for point-of-need screening of flunitrazepam and suggest that GOx/GluHD-FeSPC holds promise as an effective analytical tool to prevent phenomena of covert drug administration.

Difference in long-term relapse rates between youths with ketamine use and those with stimulants use

BACKGROUND

Understanding the relapse risk among different illicit drugs is vital for developing an adequate relapse prevention policy. Therefore, the current study aims to explore the potential difference in long-term relapse rates between youths who use ketamine and those who use stimulants (3,4-Methylenedioxymethamphetamine [MDMA] or methamphetamine).

METHODS

The study's participants included 92 youths with ketamine use (ketamine group, mean age: 16.0 years) and 43 youths with MDMA/methamphetamine use (stimulants group, mean age: 16.1 years) that had undergone a family-oriented treatment program in a medical center in Taiwan. All participants were followed up for a maximum of 7 years in order to observe their long-term outcomes with regard to substance use relapse.

RESULTS

During the follow-up period, compared to the 34.8% relapse rate in ketamine users, their counterparts who used MDMA or methamphetamine had a significantly higher relapse rate (60.5%, Adjusted HR = 1.86, 95%CI: 1.06-3.28, p = 0.032). Of the youths in the ketamine group that relapsed, 65.6% continued to use ketamine in their relapse event, while 34.4% switched to MDMA or methamphetamine. Among the relapsing youths in the stimulants group, 84.6% continued to use MDMA or methamphetamine in their relapse event, while 15.4% switched to ketamine (p = 0.042).

CONCLUSIONS

Compared to adolescents who use ketamine, those using MDMA or methamphetamine had higher relapse rates and were more likely to use the same type of drug upon relapsing. These results can serve as a crucial reference for developing relapse prevention policies of illicit drugs for the youth population.

Clinical management of gamma-hydroxybutyrate (GHB) withdrawal delirium with CIWA-Ar protocol

Gamma-hydroxybutyrate (GHB) is a synthetic drug used mainly for recreational purpose. Although the prevalence of GHB abuse is low in Taiwan, GHB has become increasingly popular in certain subpopulations such as clubbers and men who have sex with men (MSM). GHB dependence could be associated with severe withdrawal syndrome including hallucinations and delirium. Despite systematic studies on detoxification and management of GHB withdrawal have been performed, no validated measurement for severity of GHB withdrawal syndrome is available. Here we present a case of GHB withdrawal delirium that was treated successfully with fixed and symptom-triggered benzodiazepine dosing regimen based on Clinical Institute Withdrawal Assessment for Alcohol-Revised (CIWA-Ar) scale. The utilization of CIWA-Ar in such cases could offer useful guidance for benzodiazepine dosing. To the best of our knowledge, this is the first case report of GHB withdrawal delirium in Taiwan.

Shifting characteristics of ecstasy users ages 12-34 in the United States, 2007-2014

BACKGROUND

Ecstasy/MDMA has been one of the most prevalent party drugs for decades, and powder ecstasy recently increased in popularity. We examined trends in use to determine who to best target for prevention and harm reduction.

METHODS

Secondary analysis of the 2007-2014 National Survey on Drug Use and Health, a repeated cross-sectional, nationally representative probability sample, was conducted. Linear trends in past-year ecstasy use and trends in demographic and other past-year substance use characteristics among ecstasy users were examined among participants ages 12-34 (N=332,560).

RESULTS

Past-year prevalence of ecstasy use was stable across years at 2% (P=0.693). Over time, the proportion of ecstasy users with a college degree increased from 11.5% in 2007/08 to 24.5% in 2013/14 (P<0.001). The proportion of users who were age 12-17 decreased, as did proportions of users who are non-Hispanic black, and reported income <$20,000/year (Ps<0.001). Prevalence of past-year use of marijuana, LSD, ketamine, and DMT/AMT/Foxy increased among ecstasy users (Ps<0.05); DMT/AMT/Foxy use increased more than four-fold from 2.1% in 2007/08 to 8.7% in 2013/14. Perception of great risk associated with LSD use decreased among users and ease of obtaining LSD increased (Ps<0.05). Past-year use of 5 or more other substances also increased over time (P<0.05).

CONCLUSIONS

Ecstasy use in the US appears to be increasing among those with college degrees and use of other substances among ecstasy users is growing-particularly use of otherwise rare substances such as tryptamines. Results inform prevention and harm reduction strategies in this increasingly shifting group of ecstasy users.

Alcohol amplifies ketamine-induced apoptosis in primary cultured cortical neurons and PC12 cells through down-regulating CREB-related signaling pathways

Recreational use of ketamine (KET) has been increasing worldwide. Previous studies have demonstrated that KET induced neurotoxicity; however, few studies have examined how alcohol (ALC) affects KET-induced neurotoxicity. In light of the fact that some KET abusers combine KET with ALC, the present study was aimed to investigate the effects of ALC on KET-induced neurotoxicity and the underlying mechanism in vitro. Our data revealed that co-treatment with ALC and KET was more detrimental to cell viability than KET single treatment in both PC12 cells and primary cultured rat cortical neurons. Furthermore, ALC exacerbated KET-induced apoptosis characterized by morphological changes and the sub-G1 phase increase, which were mitigated by the pretreatment of CNQX, a known alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA)/kainite (KA) receptor antagonist. In addition, ALC and KET co-treatment led to intracellular Ca²⁺ overload, down-regulation of p-Akt, p-CREB, PKA, CaMK-IV, Bcl-2 and BDNF expression and up-regulation of cleaved caspase-3 and Bax expression, which can be attenuated by CNQX pretreatment. These results indicate that the potentiation of ALC on KET-induced neurotoxicity was related to the down-regulation of CREB-related pathways. Our present study also indicates that ALC and KET co-abuse might cause serious neurotoxicity which should be conveyed to the public and drew enough attention.

DSM-5 cannabis use disorder, substance use and DSM-5 specific substance-use disorders: Evaluating comorbidity in a population-based sample

Cannabis use disorder (CUD) is frequently associated with concurrent substance use and/or comorbid substance use disorders (SUDs); however there is little specificity with regard to commonly abused individual drug types/classes. This study therefore aimed to provide insight into the degree of these co-occurring relationships across several specific newer and older generation illicit and prescription drugs. 36,309 adults aged 18+ from wave 3 of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC-III) were assessed. Weighted cross-tabulations and multivariable logistic regression analyses were used to evaluate comorbidity between current DSM-5 CUD, substance use and DSM-5 SUD. Current DSM-5 CUD is associated with greater lifetime use of all examined drug classes, and previous 12-month use of several newer-class illicit and prescription stimulant-based substances (all p< 0.05). Current DSM-5 CUD was similarly associated with increased incidence of a range of DSM-5 SUDs and was independently associated with concurrently reporting current DSM-5; sedative (Adjusted OR= 5.1, 95%CI 2.9-9.0), cocaine (AOR= 9.3, 95%CI 5.6-15.5), stimulant (AOR= 4.3, 95%CI 2.3-7.9), club drug (AOR= 16.1, 95%CI 6.3-40.8), opioid (AOR= 4.6, 95%CI 3.0-6.8) and alcohol-use disorder (AOR= 3.0, 95%CI 2.5-3.7); but not heroin or 'other' drug use disorder (both p>0.05). High comorbidity exists between DSM-5 CUD and many specific DSM-5 SUDs. Newer-class illicit and prescription stimulant-based drug use disorders are overrepresented among those with DSM-5 CUD. These findings underscore the need for tailored treatment programs for those presenting with DSM-5 CUD, and for greater treatment specification where poly-drug use is evident.

Metabolism and metabolomics of ketamine: a toxicological approach

Ketamine is a phencyclidine derivative and a non-competitive antagonist of N-methyl-D-aspartate (NMDA) receptor for which glutamate is the full agonist. It produces a functional dissociation between the thalamocortical and limbic systems, a state that has been termed as dissociative anaesthesia. Considerable variability in the pharmacokinetics and pharmacodynamics between individuals that can affect dose-response and toxicological profile has been reported. This review aims to discuss pharmacokinetics of ketamine, namely focusing on all major and minor, active and inactive metabolites. Both ketamine optical isomers undergo hepatic biotransformation through the cytochrome P450, specially involving the isoenzymes 3A4 and 2B6. It is first N-demethylated to active metabolite norketamine. Different minor pathways have been described, namely hydroxylation of the cyclohexanone ring of ketamine and norketamine, and further conjugation with glucuronic acid to increase renal excretion. More recently, metabolomics data evidenced the alteration of several biological pathways after ketamine administration such as glycolysis, tricarboxylic acid cycle, amino acids metabolism and mitochondrial β-oxidation of fatty acids. It is expected that knowing the metabolism and metabolomics of ketamine may provide further insights aiming to better characterize ketamine from a clinical and forensic perspective.

Trends in cannabis use disorders among racial/ethnic population groups in the United States

BACKGROUND

Minority groups generally experience more disparities than whites in behavioral healthcare use. The population of racial/ethnic groups is growing faster than whites. Given increased concerns of cannabis use (CU) and its associations with health conditions, we examined national trends in cannabis use disorder (CUD) among adults aged ≥18 by race/ethnicity.

METHODS

Data were from the 2005-2013 National Surveys on Drug Use and Health (N=340,456). We compared CU patterns and the conditional prevalence of CUD among cannabis users by race/ethnicity to understand racial/ethnic variations in CUD.

RESULTS

Approximately 1.5% of adults met criteria for a CUD in the past year. Regardless of survey year, cannabis dependence was more common than cannabis abuse, representing 66% of adults with a CUD. Across racial/ethnic groups, the prevalence of cannabis abuse and dependence remained stable during 2005-2013. In the total adult sample, the odds of weekly CU, monthly CU, and cannabis dependence were greater among blacks, native-Americans, and mixed-race adults than whites. Among cannabis users, the odds of cannabis abuse and dependence were greater among blacks, native-Americans, and Hispanics than whites. Logistic regression controlling for age, sex, education, and survey year indicated an increased trend in monthly CU and weekly CU in the total sample and among past-year cannabis users. Younger age, male sex, and low education were associated with increased odds of cannabis dependence.

CONCLUSIONS

The large sample provides robust information that indicates a need for research to monitor CUD and identify culturally appropriate interventions especially for targeting minority populations.

An intravenous self-administration procedure for assessing the reinforcing effects of hallucinogens in nonhuman primates

INTRODUCTION

Self-administration procedures are the gold standard for investigating the reinforcing effects of drugs. The notable exception to good correspondence between laboratory self-administration studies and human drug taking behavior has historically been the classic hallucinogens.

METHOD

The present study used a well-established daily access procedure, followed by a novel intermittent access procedure, to investigate the reinforcing effects of LSD in baboons.

RESULTS

Rates of self-injection in the daily access procedure were minimal. One baboon self-administered 0.001mg/kg and a second baboon self-administered 0.0032mg/kg above vehicle levels, though rates of self-injection were clearly low and neither of the two remaining baboons self-administered any LSD dose tested in the daily access procedure. Rates of self-injection using an intermittent access procedure with discriminative stimuli resulted in two doses of LSD being self-administered above vehicle levels in two of three baboons tested (0.01 and 0.032mg/kg in one baboon; 0.0032 and 0.01mg/kg in a second). In addition, the number of self-injections at these doses was higher (range=3-6 injections) in the intermittent access procedure than in the daily access procedure (range=1-2 injections).

DISCUSSION

The present study is the first to demonstrate LSD self-administration in a laboratory animal, and though the results are limited, they indicate intermittent access procedures with discriminative stimuli may provide a reliable and valid method for investigating the reinforcing effects of IV self-administered hallucinogens in laboratory animals. The usefulness of such procedures should be further evaluated in a larger number of subjects.

The behavioural profile of gamma-hydroxybutyrate, gamma-butyrolactone and 1,4-butanediol in humans

Gamma-hydroxybutyrate (GHB) is a putative neurotransmitter, a drug of abuse, and a medical treatment for narcolepsy and other neuropsychiatric disorders. Its precursors gamma-butyrolactone (GBL) and 1,4-butanediol (1,4-BD) are endogenously converted to GHB and thereby exert their psychobehavioural effects. In humans, GHB has a wide spectrum of properties ranging from stimulation and euphoria in lower doses, to sedation, deep sleep, and coma after ingestion of high doses. However, behavioural studies in healthy volunteers remain scarce and are usually limited to psychomotor performance testing. Most available data arise from either qualitative studies with illicit users or clinical trials examining therapeutic properties of GHB (then usually termed sodium oxybate). Here, we present an overview of the behavioural effects of GHB, GBL, and 1,4-BD in these three populations. GHB and its precursors strongly influence behaviours related to core human autonomic functions such as control of food intake, sexual behaviour, and sleep-wake regulation. These effects are instrumentalised by illicit users and clinically utilised in neuropsychiatric disorders such as narcolepsy, fibromyalgia, and binge-eating syndrome. Considering the industry withdrawal from psychopharmacology development, repurposing of drugs according to their behavioural and clinical profiles has gained increasing relevance. As such, GHB seems to be an attractive candidate as an experimental therapeutic in depression.

Comprehensive Application of Time-of-flight Secondary Ion Mass Spectrometry (TOF-SIMS) for Ionic Imaging and Bio-energetic Analysis of Club Drug-induced Cognitive Deficiency

Excessive exposure to club drug (GHB) would cause cognitive dysfunction in which impaired hippocampal Ca²⁺-mediated neuroplasticity may correlate with this deficiency. However, the potential changes of in vivo Ca²⁺ together with molecular machinery engaged in GHB-induced cognitive dysfunction has never been reported. This study aims to determine these changes in bio-energetic level through ionic imaging, spectrometric, biochemical, morphological, as well as behavioral approaches. Adolescent rats subjected to GHB were processed for TOF-SIMS, immunohistochemistry, biochemical assay, together with Morris water maze to detect the ionic, molecular, neurochemical, and behavioral changes of GHB-induced cognitive dysfunction, respectively. Extent of oxidative stress and bio-energetics were assessed by levels of lipid peroxidation, Na⁺/K⁺ ATPase, cytochrome oxidase, and [¹⁴C]-2-deoxyglucose activity. Results indicated that in GHB intoxicated rats, decreased Ca²⁺ imaging and reduced NMDAR1, nNOS, and p-CREB reactivities were detected in hippocampus. Depressed Ca²⁺-mediated signaling corresponded well with intense oxidative stress, diminished Na⁺/K⁺ ATPase, reduced COX, and decreased 2-DG activity, which all contributes to the development of cognitive deficiency. As impaired Ca²⁺-mediated signaling and oxidative stress significantly contribute to GHB-induced cognitive dysfunction, delivering agent(s) that improves hippocampal bio-energetics may thus serve as a promising strategy to counteract the club drug-induced cognitive dysfunction emerging in our society nowadays.

Long-term effects of methamphetamine exposure in adolescent mice on the future ovarian reserve in adulthood

Currently, there is an increasing prevalence of adolescent exposure to methamphetamine (MA). However, there is a paucity of information concerning the long-term impact of early exposure to MA upon female fertility and ovarian reserve. The aim of this study was to investigate the effect of long-term MA exposure in adolescents on their ovarian reserve in adulthood. Adolescent mice received intraperitoneal injections of MA (5mg/kg, three times per week) or saline from the 21st postnatal day for an 8 week period. Morphological, histological, biochemical, hormonal and ethological parameters were evaluated. An impaired ovarian reserve and vitality was found in the group treated with MA, manifesting in morphological-apparent mitochondrial damage, an activated apoptosis pathway in the ovarian tissue, a downward expression of ovarian anti-Mullerian hormone (AMH), a decreased number of primordial and growing follicles, an increased number of atretic follicles, and a depressed secretion of AMH, estradiol and progesterone from granulosa cells. However, no significant difference was noticed regarding the estrous cycle, the mating ability and the fertility outcome in the reproductive age of the mice after a period of non-medication. The present results confirmed that a long term exposure to methamphetamine in adolescent mice does have an adverse impact on their ovarian reserve, which indicates that such an early abuse of MA might influence the fertility lifespan of the female mouse.

Correlates of African American female adolescent offenders 3, 4-Methylenedioxymethamphetamine (MDMA or "Ecstasy") use and sexually transmitted infection morbidity

The current study was designed to determine the extent to which self-reported ecstasy use in a population of juvenile adolescent detainees in a southern state is associated with high-risk health behaviors pertaining to sexually transmitted infection (STI) symptomology and past history of STI occurrence. Participants were 764 African American females extracted from an overall sample of 2,260 juvenile offenders housed at selected Youth Development Campuses in the state of Georgia. Significance tests were conducted using univariate logistic regressions to examine the independent associations of participant's self-reported ecstasy use and dichotomized HIV risk behavior correlates and history of having a prior STI before the most recent incarceration Participants who reported ecstasy use prior to incarceration were 1.7 (OR = 1.68, 95% CI = 0.78-3.64) and 1.8 times (OR = 1.87, 95% CI = 1.24-2.81) more likely respectively to indicate having had genital warts or chlamydia, and were more than 1.5 times (OR = 2.21, 95% CI = 0.83-5.44) and two times more likely to report having had gonorrhea or herpes, accordingly. Prevention programs for adolescent offender populations should develop interventions that target adolescents' substance use behavior as a function of STI risk taking as well as being culturally competent to deal specifically with these problem behaviors.

Illicit drug use among rave attendees in a nationally representative sample of US high school seniors

BACKGROUND

The popularity of electronic dance music and rave parties such as dance festivals has increased in recent years. Targeted samples of party-goers suggest high rates of drug use among attendees, but few nationally representative studies have examined these associations.

METHODS

We examined sociodemographic correlates of rave attendance and relationships between rave attendance and recent (12-month) use of various drugs in a representative sample of US high school seniors (modal age: 18) from the Monitoring the Future study (2011-2013; Weighted N=7373).

RESULTS

One out of five students (19.8%) reported ever attending a rave, and 7.7% reported attending at least monthly. Females and highly religious students were less likely to attend raves, and Hispanics, students residing in cities, students with higher income and those who go out for fun multiple times per week were more likely to attend. Rave attendees were more likely than non-attendees to report use of an illicit drug other than marijuana (35.5% vs. 15.6%, p<0.0001). Attendees were more likely to report use of each of the 18 drugs assessed, and attendees were more likely to report more frequent use (≥6 times) of each drug (ps<0.0001). Controlling for sociodemographic covariates, frequent attendance (monthly or more often) was associated with higher odds of use of each drug (ps<0.0001). Frequent attendees were at highest risk for use of "club drugs."

DISCUSSION

Findings from this study can help inform prevention and harm reduction among rave attendees at greatest risk for drug use.

An examination of sociodemographic correlates of ecstasy use among high school seniors in the United States

BACKGROUND

Although ecstasy (MDMA) use is not as prevalent in the United States (US) as it was in the early 2000s, use remains popular among adolescents and young adults. Few recent studies have examined ecstasy use in national samples among those at particularly high risk for use-adolescents approaching adulthood. Research is needed to delineate sociodemographic correlates of use in this group.

METHODS

Data were examined from a nationally representative sample of high school seniors in the US (modal age = 18) from the Monitoring the Future study (years 2007-2012; weighted N = 26,504). Data from all cohorts were aggregated and correlates of recent (last 12-month) use of ecstasy were examined.

RESULTS

Roughly 4.4% of high school seniors reported use of ecstasy within the last year. Females and religious students were consistently at lower odds for use. Black and Hispanic students, and students residing with two parents, were at lower odds for ecstasy use, until controlling for other drug use. Odds of use were consistently increased for those residing in a city, students with weekly income of >$50 from a job, and students earning >$10 weekly from other sources. Lifetime use of alcohol, cigarettes, marijuana, and other illicit drugs each robustly increased odds of ecstasy use.

CONCLUSION

Subgroups of high school seniors, defined by specific sociodemographic factors, and those who have used other drugs, are currently at high risk for ecstasy initiation and use. Since ecstasy is regaining popularity in the US, prevention efforts should consider these factors.

Use of prescription drugs and future delinquency among adolescent offenders

Non-medical use of prescription drugs (NMUPD) by adolescents is a significant public health concern. The present study investigated the profile of NMUPD in 1349 adolescent offenders from the Pathways to Desistance project, and whether NMUPD predicted future delinquency using longitudinal data. Results indicated that increased frequency and recency of NMUPD in adolescent offenders are related to some demographic factors, as well as increased risk for violence exposure, mental health diagnoses, other drug use, and previous delinquency, suggesting that severity of NMUPD is important to consider. However, ANCOVA analyses found that NMUPD was not a significant predictor of drug-related, non-aggressive, or aggressive delinquency 12 months later beyond other known correlates of delinquency. Age, sex, exposure to violence, lower socioeconomic status, more alcohol use, and having delinquency histories were more important than NMUPD in predicting future delinquency. These findings suggest that although NMUPD is an important risk factor relating to many correlates of delinquency, it does not predict future delinquency beyond other known risk factors.

The acute effects of MDMA and ethanol administration on electrophysiological correlates of performance monitoring in healthy volunteers

RATIONALE

Knowing how commonly used drugs affect performance monitoring is of great importance, because drug use is often associated with compromised behavioral control. Two of the most commonly used recreational drugs in the western world, 3,4-methylenedioxymethamphetamine (MDMA or "ecstasy") and ethanol (alcohol), are also often used in combination. The error-related negativity (ERN), correct-related negativity (CRN), and N2 are electrophysiological indices of performance monitoring.

OBJECTIVES

The present study aimed to investigate how ethanol, MDMA, and their co-administration affect performance monitoring as indexed by the electrophysiological correlates.

METHODS

Behavioral and EEG data were obtained from 14 healthy volunteers during execution of a speeded choice-reaction-time task after administration of ethanol, MDMA, and combined ethanol and MDMA, in a double-blind, placebo-controlled, randomized crossover design.

RESULTS

Ethanol significantly reduced ERN amplitudes, while administration of MDMA did not affect the ERN. Co-administration of MDMA and ethanol did not further impair nor ameliorate the effect of ethanol alone. No drug effects on CRN nor N2 were observed.

DISCUSSION

A decreased ERN following ethanol administration is in line with previous work and offers further support for the impairing effects of alcohol intoxication on performance monitoring. This impairment may underlie maladaptive behavior in people who are under influence. Moreover, these data demonstrate for the first time that MDMA does not affect performance monitoring nor does it interact with ethanol in this process. These findings corroborate the notion that MDMA leaves central executive functions relatively unaffected.

Evaluation of cytotoxicity and mutagenicity of the benzodiazepine flunitrazepam in vitro and in vivo

Flunitrazepam (FNZ) is a sedative benzodiazepine prescribed for the short-term treatment of insomnia. However, there are concerns regarding possible carcinogenic or genotoxic effects of this medicine. Thus, the aim of this study was to evaluate the cytotoxic, clastogenic and aneugenic effects of FNZ in hepatoma cells from Rattus norvegicus (HTC) in vitro and in bone marrow cells of Wistar rats in vivo. These effects were examined in vitro following treatment with 0.2, 1.0, 5.0 or 10 μg/mL FNZ using a micronucleus test with a cytokinesis block or in vivo using a chromosomal aberration test following treatment with 7, 15 or 30 μg/mL/kg body weight. The results showed that the benzodiazepine concentrations tested were not cytotoxic, aneugenic or clastogenic. However, considering the adverse effects of using this benzodiazepine, more studies are required.

Patterns and Transitions in Substance Use Among Young Swiss Men

This study investigates the potential stages of drug use. Data from the longitudinal Cohort Study on Substance Use Risk Factors were used ( N = 5,116). Drug use (alcohol, tobacco, and 16 illicit drugs) over the previous 12 months was assessed at two time points. Patterns and trajectories of drug use were studied using latent transition analysis (LTA). This study’s substantive contributions are twofold. First, the pattern of drug use displayed the well-known sequence of drug involvement (licit drugs to cannabis to other illicit drugs), but with an added distinction between two kinds of illicit drugs (“middle-stage” drugs: uppers, hallucinogens, inhaled drugs; and “final-stage” drugs: heroin, ketamine, GHB/GBL, research chemicals, crystal meth, and spice). Second, subgroup membership was stable over time, as the most likely transition was remaining in the same latent class.

Illicit and nonmedical drug use among Asian Americans, Native Hawaiians/Pacific Islanders, and mixed-race individuals

BACKGROUND

The racial/ethnic composition of the United States is shifting rapidly, with non-Hispanic Asian-Americans, Native Hawaiians/Pacific Islanders (NHs/PIs), and mixed-race individuals the fastest growing segments of the population. We determined new drug use estimates for these rising groups. Prevalences among Whites were included as a comparison.

METHODS

Data were from the 2005-2011 National Surveys on Drug Use and Health. Substance use among respondents aged ≥ 12 years was assessed by computer-assisted self-interviewing methods. Respondents' self-reported race/ethnicity, age, gender, household income, government assistance, county type, residential stability, major depressive episode, history of being arrested, tobacco use, and alcohol use were examined as correlates. We stratified the analysis by race/ethnicity and used logistic regression to estimate odds of drug use.

RESULTS

Prevalence of past-year marijuana use among Whites increased from 10.7% in 2005 to 11.6-11.8% in 2009-2011 (P<0.05). There were no significant yearly changes in drug use prevalences among Asian-Americans, NHs/PIs, and mixed-race people; but use of any drug, especially marijuana, was prevalent among NHs/PIs and mixed-race people (21.2% and 23.3%, respectively, in 2011). Compared with Asian-Americans, NHs/PIs had higher odds of marijuana use, and mixed-race individuals had higher odds of using marijuana, cocaine, hallucinogens, stimulants, sedatives, and tranquilizers. Compared with Whites, mixed-race individuals had greater odds of any drug use, mainly marijuana, and NHs/PIs resembled Whites in odds of any drug use.

CONCLUSIONS

Findings reveal alarmingly prevalent drug use among NHs/PIs and mixed-race people. Research on drug use is needed in these rising populations to inform prevention and treatment efforts.

Comorbid substance use disorders with other Axis I and II mental disorders among treatment-seeking Asian Americans, Native Hawaiians/Pacific Islanders, and mixed-race people

Little is known about behavioral healthcare needs of Asian Americans (AAs), Native Hawaiians/Pacific Islanders (NHs/PIs), and mixed-race people (MRs)-the fastest growing segments of the U.S. population. We examined substance use disorder (SUD) prevalences and comorbidities among AAs, NHs/PIs, and MRs (N = 4572) in a behavioral health electronic health record database. DSM-IV diagnoses among patients aged 1-90 years who accessed behavioral healthcare from 11 sites were systematically captured: SUD, anxiety, mood, personality, adjustment, childhood-onset, cognitive/dementia, dissociative, eating, factitious, impulse-control, psychotic/schizophrenic, sleep, and somatoform diagnoses. Of all patients, 15.0% had a SUD. Mood (60%), anxiety (31.2%), adjustment (30.9%), and disruptive (attention deficit-hyperactivity, conduct, oppositional defiant, disruptive behavior diagnosis, 22.7%) diagnoses were more common than others (psychotic 14.2%, personality 13.3%, other childhood-onset 11.4%, impulse-control 6.6%, cognitive 2.8%, eating 2.2%, somatoform 2.1%). Less than 1% of children aged <12 years had SUD. Cannabis diagnosis was the primary SUD affecting adolescents aged 12-17. MRs aged 35-49 years had the highest prevalence of cocaine diagnosis. Controlling for age at first visit, sex, treatment setting, length of treatment, and number of comorbid diagnoses, NHs/PIs and MRs were about two times more likely than AAs to have ≥ 2 SUDs. Regardless of race/ethnicity, personality diagnosis was comorbid with SUD. NHs/PIs with a mood diagnosis had elevated odds of having SUD. Findings present the most comprehensive patterns of mental diagnoses available for treatment-seeking AAs, NHs/PIs, and MRs in the real-world medical setting. In-depth research is needed to elucidate intraracial and interracial differences in treatment needs.

Tobacco use among Asian Americans, Native Hawaiians/Pacific Islanders, and mixed-race individuals: 2002-2010

BACKGROUND

Non-Hispanic Asian Americans, Native Hawaiians/Pacific Islanders (NHs/PIs), and mixed-race individuals are the fastest growing segments of the US population. We examined prevalences and correlates of tobacco use among these understudied groups. Prevalences among whites were included as a comparison.

METHODS

Data were drawn from the 2002-2010 National Surveys on Drug Use and Health. Respondents aged ≥12 years were assessed for current (past-month) use of cigarettes, cigars, smokeless tobacco (chewing tobacco, snuff), and pipe tobacco. Respondents' race/ethnicity, age, sex, household income, government assistance, urbanicity of residence, residential stability, self-rated health, alcohol use, and drug use were examined as correlates.

RESULTS

Between 2002 and 2010, there was a decline in the prevalence of cigarette smoking among whites (26.9% in 2002; 24.3% in 2010) and Asian Americans (18.0% in 2002; 11.1% in 2010). Prevalence of pipe tobacco use among mixed-race individuals increased from 0.2% in 2002 to 1.6% in 2010; there was little change in the prevalence of cigar and smokeless tobacco use in these racial/ethnic groups. Adjusted analyses showed that, compared with Asian Americans, mixed-race individuals had greater odds of using four tobacco products, and NHs/PIs had greater odds of using cigarettes, cigars, and smokeless tobacco. Regardless of race/ethnicity, male sex was a correlate of use of cigars, smokeless tobacco, and pipe tobacco; alcohol and drug use increased the odds of cigarette and cigar smoking.

CONCLUSIONS

These new findings show prevalent tobacco use among NHs/PIs and mixed-race individuals, and highlight the importance of including these populations in future research and reporting.

Acute effects of three club drugs on the striatum of rats: evaluation by quantitative autoradiography with [18F]FDOPA

In this work, we used quantitative autoradiography to study the acute effect of cocaine, methamphetamine, and ketamine on the uptake of [(18)F]FDOPA in the striatum of rats. Drugs were treated 0.5 h before (pre-treated), and 1.5 h after (post-treated) [(18)F]FDOPA injections, rats were then sacrificed at 2 h post [(18)F]FDOPA injections to determine the striatum/frontal cortex binding ratios in the striatum. The ratios were lower in the post-treated groups than those of the pre-treated groups, suggesting a net effect of inhibition of trapping of the tracer. The order of uptake inhibition is: ketamine>methamphetamine>cocaine.

Correlates of ecstasy use in the Swedish general population

The aim of the present study was to report independent correlates of ecstasy use in the Swedish general population. Data were drawn from a Swedish national household survey conducted in 2008-2009 on a random, stratified sample of 58,000 inhabitants of Sweden, aged 15 to 64. The response rate was 38.3%. Logistic regression analysis was used to identify correlates of recent (past-year) and former ecstasy use. Results are discussed and limitations of the study are noted.

Classification of pulmonary hypertension

Pulmonary hypertension (PH) can develop in association with many different diseases and risk factors, and its presence is nearly always associated with reduced survival. The prognosis and management of PH is largely dependent upon its underlying etiology and severity of disease. The combination of clinical and hemodynamic classifications of PH provides a framework for the diagnostic evaluation of PH to establish a final clinical diagnosis that guides therapy. As our understanding of the different pathologic mechanisms that underlie the syndrome of PH evolves, so too will the classification and treatment of PH.

Individual and peer factors associated with ketamine use among adolescents in Taiwan

The aim of this cross-sectional study was to examine the individual (demographic characteristics, substance-using behaviors, emotional status, and negative outcome expectancy) and peer factors associated with ketamine use in Taiwanese adolescents. A total of 9,860 adolescents completed the self-report questionnaires without omission. Demographic characteristics, substance-using behaviors, emotional status, negative outcome expectancy, and peer factors were compared between the ketamine users and non-users using the Mann-Whitney U test and the Chi-square test, and then significant factors were further selected for stepwise logistic regression analysis to examine the associated factors of ketamine use. Sixty-nine (0.7%) participants reported having used ketamine in the past year. The results of logistic regression analysis indicated that ketamine users were more likely to use marijuana, smoke cigarettes, have peers using illicit drugs, and have a lower level of negative outcome expectancy regarding using ketamine than ketamine non-users. The associated factors found in this study should be taken into consideration when developing prevention and intervention programs for ketamine use in adolescents.

Simultaneous polysubstance use among Danish 3,4-methylenedioxymethamphetamine and hallucinogen users: combination patterns and proposed biological bases

OBJECTIVE

To describe patterns of simultaneous polysubstance use (SPU) among Danish 3,4-methylenedioxymethamphetamine (MDMA) ("Ecstasy") and hallucinogen users.

METHODS

A cross-sectional survey of 98 active MDMA and/or hallucinogen users recruited through homepage advertisements, flyers, and word of mouth in Denmark. Lifetime and recent substance use and SPU at last recalled use was described by structured interviews. Hair samples from a subset of participants were analyzed for MDMA.

RESULTS

The participants had used an average of 12.6 (95% confidence interval: 11.7-13.4) psychoactive substances during their lifetime. SPU was prevalent among MDMA, d-lysergic acid diethylamide (LSD), and psilocybin users, in particular with alcohol and cannabis. Among MDMA users, 69% had combined MDMA with amphetamines, 56% with hallucinogens, and 47% with cocaine. At last recalled use, MDMA was taken with 2.1 ± 1.2 substances in 32 different combinations. The participants preferred specific drug combinations and named several, which in their experience enhanced or counteracted each other. Alcohol and cannabis were typically used before, during, and after MDMA, LSD, and psilocybin, whereas amphetamines were predominantly taken before these substances. When LSD was combined with MDMA, the majority took MDMA after LSD.

CONCLUSIONS

Simultaneous polysubstance use was common among Danish MDMA and hallucinogen users, and patterns of preferred substance combinations were evident.

Distribution of methamphetamine and its metabolite amphetamine in acute and subacute ethanol-methamphetamine combination abuse model rats

The aim of this study is to investigate the distribution of methamphetamine (MA) and its metabolite amphetamine (AP) in rat models of acute and subacute MA-ethanol combination abuse. Rats were fed with 20% ethanol for 4 weeks (chronic active-drinking group), and MA was injected intraperitoneally into chronically drinking and normal rats over 5 and 14 days, respectively. Then the rats from the acute and subacute combination abuse groups were euthanized, and ethanol, MA, and AP concentrations in samples were quantified. Except for the similar ethanol concentrations among acute and subacute groups, the MA and AP levels between groups were quite different. The concentrations of MA and AP in rats' liver, lung, kidney, and brain were much higher than other tissues, regardless of combination with ethanol. Also, MA and AP levels in subacute rats groups were higher than those in acute groups, and the levels of MA and the formation of AP in rats subjected to the combination abuse with ethanol were higher than in MA-only intoxicated rats. We conclude that ethanol has no bearing on the MA and AP distribution in body fluids and tissues, yet it can increase MA levels and markedly accelerate the formation of AP in combination-abuse rats. Comparing the acute and subacute combination-abuse rats' samples, it can be deduced that various accumulated amounts of MA and AP were unaffected by ethanol, even after multi-dose injection, regardless of acute or subacute use.

Flunitrazepam intake in male offenders

The abuse of flunitrazepam (FZ) compounds is worldwide, and several studies have reflected on the consequences with regard to violence, aggression and criminal lifestyle of FZ users. Criminals take high doses of FZ or some other benzodiazepines to "calm down" before the planned crime. There is support from earlier studies that most likely, all benzodiazepines may increase aggression in vulnerable males. Chronic intake of high doses of FZ increases aggression in male rats. Because psychopathy involves aggression, we have examined whether psychopathy as well as any of the four facets of the Psychopathy Checklist-Revised (PCL-R) (Interpersonal, Affective, Lifestyle and Antisocial) are related to different substance use disorders, with the focus on FZ. We have also examined the relationship between each PCL-R item and FZ use. Participants were 114 male offenders aged 14-35 years, all of whom were convicted for severe, predominantly violent, offences. Substance use, including FZ, was not more common in those who scored high in psychopathy. Use of FZ was more common in offenders who scored high in Facet 4 (Antisocial) of the PCL-R (odds ratio = 4.30, 95% CI 1.86-9.94). Only one of the PCL-R items, "Criminal versatility", was significantly associated with FZ use (odds ratio = 3.7). It may be concluded that intake of FZ has a specific relationship to only one of the facets and not to psychopathy per se. The findings have also important theoretical implications because Facet 4 is not a key factor of the construct of psychopathy. Clinical implications of the article: We have used the new two-factor and four-facet theoretical model of psychopathy in the young offender population, many of them with one or more substance use disorders. The present results suggest that antisocial behavior defined by Facet 4 (poor behavioral control, early behavior problems, juvenile delinquency, revocation of conditional release and criminal versatility) in the studied subjects is more typical for FZ users than it is for non-FZ users. This may have implications for assessment and treatment. Clinicians should be aware that criminals with high scores on Facet 4 have a more than fourfold odds of being a FZ user. This conclusion has an important clinical implication because FZ abuse is very common and is not always the focus of a forensic psychiatric assessment.

The discriminative stimulus effects of midazolam are resistant to modulation by morphine, amphetamine, dizocilpine, and γ-butyrolactone in rhesus monkeys

RATIONALE

Although abuse of benzodiazepines alone is uncommon, it is high in polydrug abusers, including those who primarily use opioids or stimulants.

OBJECTIVES

This study investigated whether drugs that are abused (e.g., amphetamine) or drugs that have mechanisms of action similar to abused drugs (e.g., morphine) alter the discriminative stimulus effects of the benzodiazepine midazolam.

METHODS

Three rhesus monkeys discriminated 0.56 mg/kg of midazolam while responding under a fixed-ratio 10 schedule of food presentation. Dose-effect curves were determined for midazolam alone and in the presence of morphine (opioid receptor agonist), amphetamine (dopamine receptor indirect agonist), dizocilpine (N-methyl-D: -aspartic acid receptor antagonist), or γ-butyrolactone (prodrug of γ-hydroxybutyrate, which acts primarily at GABA(B) receptors).

RESULTS

Doses of midazolam larger than 0.32 mg/kg produced ≥80% midazolam-lever responding. When administered alone, morphine, amphetamine, dizocilpine, and γ-butyrolactone did not produce midazolam-lever responding, although large doses of each drug eliminated responding; when administered in combination with midazolam, they did not alter the discriminative stimulus effects of midazolam up to doses that markedly decreased response rates.

CONCLUSIONS

The current study demonstrates a lack of modulation of the discriminative stimulus effects of midazolam by morphine, amphetamine, dizocilpine, and γ-butyrolactone. Other effects of benzodiazepines, such as their reinforcing effects, might be altered by these other drugs, or benzodiazepines might modulate the discriminative stimulus or reinforcing effects of the other drugs, which might contribute to the relatively high incidence of benzodiazepine abuse among polydrug abusers.