Use of ecstasy and other psychoactive substances among school-attending adolescents in Taiwan: national surveys 2004-2006

Feasibility of Intervention Program to Prevent Adolescent Health-Compromising Behaviors

Most people start experimenting with and/or initiating health-compromising behaviors and establishing behavioral patterns during adolescence. Possible selves and episodic future thinking have been used to foster behavioral changes. In this study, we aimed to (1) develop a program incorporating possible selves and episodic future thinking to decrease the risks associated with health-compromising behaviors, and (2) examine the feasibility and fidelity of implementing this intervention among Taiwanese adolescents. A novel combination of existing intervention approaches tailored for the Taiwanese context was applied to develop a school-based intervention, which we named the Future Mapping Master program. This program contains four core units: exploring the self, setting goals, developing strategies and problem solving, and understanding the threats of health-compromising behaviors. It includes daily episodic future thinking visualization exercises. The feasibility evaluation was conducted with 88 adolescents aged 12-14 years. Feedback from teachers and students supported the proposed program's feasibility and revealed favorable reactions to the intervention. The Future Mapping Master program is feasible and offers promising strategies for implementation in Taiwanese school settings.

Ketamine use disorder: preclinical, clinical, and neuroimaging evidence to support proposed mechanisms of actions

Ketamine, a noncompetitive NMDA receptor antagonist, has been exclusively used as an anesthetic in medicine and has led to new insights into the pathophysiology of neuropsychiatric disorders. Clinical studies have shown that low subanesthetic doses of ketamine produce antidepressant effects for individuals with depression. However, its use as a treatment for psychiatric disorders has been limited due to its reinforcing effects and high potential for diversion and misuse. Preclinical studies have focused on understanding the molecular mechanisms underlying ketamine's antidepressant effects, but a precise mechanism had yet to be elucidated. Here we review different hypotheses for ketamine's mechanism of action including the direct inhibition and disinhibition of NMDA receptors, AMPAR activation, and heightened activation of monoaminergic systems. The proposed mechanisms are not mutually exclusive, and their combined influence may exert the observed structural and functional neural impairments. Long term use of ketamine induces brain structural, functional impairments, and neurodevelopmental effects in both rodents and humans. Its misuse has increased rapidly in the past 20 years and is one of the most common addictive drugs used in Asia. The proposed mechanisms of action and supporting neuroimaging data allow for the development of tools to identify 'biotypes' of ketamine use disorder (KUD) using machine learning approaches, which could inform intervention and treatment.

Clinical and behavior characteristics of individuals who used ketamine

This study aims to depict and compare clinical characteristics and risk behavior among groups of individuals using ketamine, polydrugs or smoking cigarette. A total of 185 drug-using participants and 49 smokers participated in this study. A cross-sectional interview was used to collect information on demographics, drug- and sex-related behaviors, HIV serostatus, lower urinary tract symptoms (LUTS), behavioral dispositions. N-back memory test was used to measure short-term memory. Result shows that 10 participants (5.41%) were HIV positive and 14 (7.57%) having LUTS. Individuals with ketamine and polydrugs use have significantly worse drug-related problem than cigarette smokers. Compared to cigarette smokers and ketamine users, individuals with polydrug users scored significantly higher on impulsivity measures. Cigarette smokers performed significantly better than the other two groups on the memory tests. A few patients had been infected with HIV and diagnosed with LUTS. Findings support that memory on short term recalls of patients with ketamine use might be impaired. Study findings warrants the necessarily of further study on influences of using ketamine.

The impact of Taiwan's implementation of a nationwide harm reduction program in 2006 on the use of various illicit drugs: trend analysis of first-time offenders from 2001 to 2017

Background

After implementing a nationwide harm reduction program in 2006, a dramatic decline in the incidence of human immunodeficiency virus (HIV) infection among people with injection drug use (IDU) was observed in Taiwan. The harm reduction program might have sent out the message discouraging the choice of IDU among illicit drug users in early stage. Based on the yearly first-time offense rates from 2001 to 2017, this study aimed to examine (1) whether the nationwide implementation of the harm reduction program in 2006 led to changes in first-time offenders’ use of heroin; (2) whether the intervention had a similar effect on the use of other illicit drugs; and (3) whether the effect of the intervention was limited to the first-time offenders of young age groups.

Methods

Yearly first-time illicit-drug offense rates from 2001 to 2017 in Taiwan were derived from two national databases for drug arrests that were verified using urine tests: the Criminal Record Processing System on Schedule I/II Drugs and the Administrative Penalty System for Schedule III/IV Substances. A hierarchy of mutually exclusive categories of drug uses was defined by the drug with the highest schedule level among those tested positive in an arrest. Segmented regression analyses of interrupted time series were used to test for the impact of the 2006 intervention.

Results

There was a decrease of 22.37 per 100,000 in the rate for heroin but no detectable level changes in that for methamphetamine or ecstasy after the 2006 intervention in Taiwan. There were baseline decreasing trends in the first-time offense rate from 2001 to 2017 for heroin and ecstasy and an increasing trend for methamphetamine, with the slopes not altered by the 2006 intervention. The postintervention decrease in the first-time offense rate for heroin was detectable among offenders less than 40 years old.

Conclusions

Our results indicate a diffusion effect of the 2006 intervention on decreasing heroin use among young offenders and have policy implications for better prevention and treatment for different age groups.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12954-021-00566-5.

Integrating health literacy into a theory-based drug-use prevention program: a quasi-experimental study among junior high students in Taiwan

BACKGROUND

In Taiwan, illegal drug use is a critical health problem during adolescence. Schools playa vital role in preventing students' illegal drug use. Accordingly, we developed and evaluated a school-based, drug-use prevention program integrating the theory of planned behavior (TPB) and health literacy for junior high school students.

AIM

This study aimed to use a theory-based program to prevent students from illegal drug use in Taiwanese junior high school students.

METHODS

We recruited 648 junior high school students aged around 13-14 years (grades 7 to 8 students) from 14 selected schools: N = 323 in the experimental group, N = 325 in the comparison group. The experimental group received 10 45-min sessions of a theory-based drug-use prevention program. The comparison group received traditional didactic teaching and drug refusal skill training. We used a generalized estimating equation (GEE) to analyze data.

RESULTS

Results of paired t-tests indicated that drug-use health literacy and TPB-related variables improved in the experimental group. The GEE analyses indicated that participants in the experimental group also demonstrated significantly improved health literacy (p < 0.001) compared to the comparison group, especially for functional (p < 0.001) and critical health literacy (p = 0.017). The experimental group also showed significant post-intervention improvement in terms of subjective norm scores (p = 0.024).

CONCLUSION

Study results demonstrated the effectiveness of a drug-use prevention program on health literacy and subjective norm through integrating the Theory of Planned Behavior and health literacy. The study supports that the future implementation of similar programs for junior high school students can integrate health literacy and subjective norms as two critical program components.

Men's decrease and women's increase in harmful alcohol use from the 2014 to 2018 national surveys in Taiwan: A harbinger for an emerging national trend in East Asia?

BACKGROUND

Gender differences in alcohol use have narrowed in Western societies, but that in Asia has been less investigated. By comparing the 2014 and 2018 waves of the national survey in Taiwan, we aimed to examine the gender differences in population trends in past-month alcohol use, binge drinking, and harmful alcohol use.

METHODS

The national survey enrolled 17,837 participants in 2014 and 18,626 participants in 2018. Binge drinking was defined as having ≥5 drinks on one occasion in the past month, and harmful alcohol use as having an Alcohol Use Disorders Identification Test score of ≥8.

RESULTS

There were significant decreases from 2014 to 2018 in the population's prevalence of past-month alcohol use, binge drinking, and harmful alcohol use. However, males and females had different trends: males showed significant reductions in all three alcohol use behaviours (a decrease of 3.79%, 1.59%, and 2.60%, respectively), while females exhibited a significant rise in harmful alcohol use (from 1.32% to 1.72%), particularly among those aged 18-29 years.

CONCLUSION

There was gender convergence in alcohol use in Taiwan, mainly due to men's decrease and women's increase in harmful alcohol use. Our findings have important implications for the intervention and prevention of the problematic use of alcohol in East Asia.

First-time offenders for recreational ketamine use under a new penalty system in Taiwan: incidence, recidivism and mortality in national cohorts from 2009 to 2017

BACKGROUND AND AIMS

Ketamine has become a new recreational drug of choice among young people in parts of Asia. Using national databases in Taiwan, this study aimed to (1) examine the yearly trend in the ketamine offence rate over time; (2) estimate the 3-year risk of drug-related re-offence and its correlates among the first-time offenders; and (3) estimate the 3-year standardized mortality ratio (SMR) among the first-time offenders.

DESIGN, SETTING AND PARTICIPANTS

Retrospective cohort studies of offenders for recreational ketamine use in a penalty system initiated in 2009. Offenders for recreational ketamine use were identified from the Administrative Penalty System for Schedule III/IV Substances database from 2009 to 2017, and the re-offence rate and mortality among first-time offenders were assessed via record-linkage within the database as well as with both the criminal drug offence database and the national mortality database. The cohort from 2009 to 2016 (n = 39 178) was used for the recidivism analysis and the cohort from 2009 to 2013 (n = 25 357) was used for the 3-year SMR analysis.

MEASUREMENTS

Recidivism was estimated using survival analysis of the event as re-arrest for using ketamine, more serious illicit drugs (Schedules I/II), or any illicit drugs (ketamine or Schedules I/II). SMRs were estimated for overall and cause-specific death within 3 years after the first offence for ketamine use.

FINDINGS

The age-standardized rates for both prevalent (1.38 per 1000) and first-time offenders (0.65 per 1000) peaked in 2013 and then decreased steadily. The 3-year risk of re-offence was 33.85% [95% confidence interval (CI) = 33.23-34.47%) for ketamine use and 39.52% (95% CI = 39.00-40.04%) for any illicit drug use. These first-time offenders had an SMR of 4.9 (95% CI = 4.3-5.4) for overall mortality, 2.1 (95% CI = 1.6-2.7) for natural deaths and 7.6 (95% CI = 6.7-8.6) for unnatural deaths.

CONCLUSIONS

Recreational ketamine use in Taiwan appears to lead not only to high risk for drug-related re-offence but also to excess mortality.

Early sexual initiation and risky sexual practices among alcohol- and tobacco-using young adults in Taiwan: mediation analysis of preceding-sex use of illicit drugs

BACKGROUND

As early sexual initiation is increasingly common in East Asia, we examined its relations to risky sexual practices in alcohol- and tobacco-using individuals in Taiwan and evaluated whether the associations were mediated through preceding-sex use of illicit drugs.

METHODS

Participants, recruited from alcohol- and tobacco-using adults aged 18 to 50 in Taipei through respondent-driven sampling (N = 1115), completed a computer-assisted self-interview covering questions on substance use and sexual experiences. In a subsample of 916 participants who had had sexual experience (median age 27), we examined the relations of early sexual initiation (< 16 years) to multiple sexual partners, casual sex, group sex, and rare condom use. Causal mediation analyses were conducted to examine whether illicit drug use preceding sex mediated these associations.

RESULTS

Around 9.3% reported early sexual initiation and the prevalence of risky sexual practices ranged from 7% (group sex) to 47% (rare condom use). Early initiators had a higher prevalence of regular binge drinking, illicit drug use, and risky sexual practices. In the multivariable analyses, higher odds of multiple sexual partners, casual sex, and group sex were consistently associated with early sexual initiation, gender, and their interaction. Mediation through preceding-sex use of illicit drugs was found between early sexual initiation and the three risky sexual practices, with the proportions mediated ranging from 17 to 19%.

CONCLUSIONS

Early sexual initiators were more likely to engage in risky sexual practices and preceding-sex use of illicit drugs partially explained this relationship, calling for more attention to this population's sexual health.

Effects of early ketamine exposure on cerebral gray matter volume and functional connectivity

Ketamine has been used for medical purposes, most typically as an anesthetic, and recent studies support its use in the treatment of depression. However, ketamine tends to be abused by adolescents and young adults. In the current study, we examined the effects of early ketamine exposure on brain structure and function. We employed MRI to assess the effects of ketamine abuse on cerebral gray matter volume (GMV) and functional connectivity (FC) in 34 users and 19 non-users, employing covariates. Ketamine users were categorized as adolescent-onset and adult-onset based on when they were first exposed to ketamine. Imaging data were processed by published routines in SPM and AFNI. The results revealed lower GMV in the left precuneus in ketamine users, with a larger decrease in the adolescent-onset group. The results from a seed-based correlation analysis show that both ketamine groups had higher functional connectivity between left precuneus (seed) and right precuneus than the control group. Compared to controls, ketamine users showed decreased GMV in the right insula, left inferior parietal lobule, left dorsolateral prefrontal cortex/superior frontal gyrus, and left medial orbitofrontal cortex. These preliminary results characterize the effects of ketamine misuse on brain structure and function and highlight the influence of earlier exposure to ketamine on the development of the brain. The precuneus, a structure of central importance to cerebral functional organization, may be particularly vulnerable to the influences of early ketamine exposure. How these structural and functional brain changes may relate to the cognitive and affective deficits remains to be determined with a large cohort of participants.

Impact of Diabetes Mellitus on Head and Neck Cancer Patients Undergoing Concurrent Chemoradiotherapy

In this retrospective study, we investigated the impact of diabetes mellitus (DM) on patients with head and neck cancer (HNC) undergoing concurrent chemoradiotherapy (CCRT). We analyzed the demographic and clinical characteristics, treatment tolerance, and toxicities of patients with HNC undergoing primary or adjuvant CCRT with or without DM between 2007 and 2016. Of the 556 patients undergoing CCRT, 84 (15.1%) had DM. Compared with patients without DM, patients with DM were significantly older (56.2 ± 11.2 vs. 51.9 ± 9.5 years, P < 0.001), received lower doses of cisplatin (adjuvant CCRT: 175.30 ± 84.03 vs. 214.88 ± 68.25, P = 0.014; primary CCRT: 142.84 ± 79.49 vs. 187.83 ± 76.19, P < 0.001), and experienced higher rates of infection (adjuvant CCRT: 52% vs. 30.5%, P = 0.042; primary CCRT: 45.8% vs. 22.9%, P < 0.001). Among patients undergoing primary CCRT, compared with those without DM, the patients with DM experienced significantly higher rates of hematologic toxicity (65.7% vs. 39.3%, P = 0.004) and treatment-related deaths (10.2% vs. 3.5%, P = 0.051); and a greater weight loss (−6.17 ± 9.27% vs. −4.49 ± 6.84, P = 0.078). Patients with HNC and DM undergoing CCRT, compared with patients without DM, experienced higher rates of infection and hematotoxicity, loss of body weight, and higher treatment-related mortality.

Chronic sub-anesthetic ketamine induces permanent hypolocomotion and impairment of hippocampus in adolescent cynomolgus monkeys

Ketamine has gained increasing popularity in adolescent drug abusers worldwide. However, relatively little is known about the long-term effects of recreational ketamine on adolescent hippocampus. The present study investigates the effects of different periods (1, 3 and 6 months) of recreational ketamine administration on locomotor activity and neuron damage in the hippocampus of adolescent cynomolgus monkeys. 32 4-year-old male cynomolgus monkeys were divided into control, 1-month, 3-month and 6-month groups. All animals in ketamine groups received daily intravenous injection with 1 mg/kg ketamine in saline for respective 1, 3 or 6 months while control group received normal saline. Automatic behaviors were recorded for 10 min before and after ketamine and saline administration. Meanwhile, the markers of apoptosis in the hippocampus were assessed using terminal deoxynucleotidyl transferase-mediated biotinylated dUTP nick end labeling (TUNEL), electron microscopy and western blotting. Results showed that ketamine significantly decreased locomotor activity, increased apoptotic neurons and pro-apoptotic proteins, cleaved Caspase-3 and Bax, while decreased the anti-apoptotic protein Bcl-2 in the hippocampus after 6-month ketamine administration. Our study suggested that chronically recreational ketamine might induce hypolocomotion and neurotoxic effect via apoptotic pathway in adolescent hippocampus of monkeys.

Predictors of five-year relapse rates of youths with substance abuse who underwent a family-oriented therapy program

BACKGROUND

Substance abuse among young people has become a serious public health problem for years. The risk of relapse among illicit drug use is essential for developing adequate substance reuse prevention policies. The purpose of the current study is to investigate the potential predictor in long-term relapse rates among young patients that underwent a family-based treatment program.

METHODS

To perform this study, 103 young patients with substance use (mean age: 16.2 years, 78.6% male) were referred to participate in a 10-week family-based treatment program. At the beginning and at the end of the treatment, the patients were required to fill out the Chinese Craving Beliefs Questionnaire (CCBQ), the Adolescents' Behavior-problem Scale (ABS), and the Family APGAR. Furthermore, the patients' caregivers had to fill out the Family APGAR, the 12-item version of the Chinese Health Questionnaire (CHQ), and the Parenting Stress Index (PSI). All patients were followed up for 5 years in order to observe their long-term outcomes regarding substance use relapse.

RESULTS

During the 10-week family-oriented programs, the CCBQ scores, the CHQ scores and the Child-domain of PSI significantly decreased. Better changes in patients' behavioral problems during the treatment program predicted a lesser likelihood of substance use relapse in the subsequent 5 years. Furthermore, methamphetamine or 3,4-methylenedioxy-methamphetamine use and living in single-parent families were two factors associated with higher relapse rates.

CONCLUSIONS

The changes in patients' behavioral problems during the treatment program may serve as a predictor of substance use relapse over the subsequent 5 years. This study's findings provide insight about substance use prevention and serve as a reference for policy-making.

Effectiveness of a brief information, motivation and behavioral skills program on stage transitions and lapse for individuals who use ketamine

OBJECTIVE

Chronic ketamine use is a significant public health and social problem in East and South East Asia and may lead to impairments in health and cognitive functioning. The study evaluated effects of an information, motivation and behavior skills (IMB) program on changes in motivational stage and ketamine use.

METHODS

Ketamine using individuals residing in the City of Taipei were recruited (N = 395): 279 selected an IMB program consisting of a 1-day workshop of six 50-minute interactive sessions provided in small groups. The remaining 116 participants selected an education-as-usual (EAU) program consisting of a 1-day workshop of six 50-minute didactic lectures provided in a large group format. Motivational stage of change and ketamine knowledge were assessed before and after the interventions. Participants were followed one year later to assess their ketamine use status.

RESULTS

No significant difference in knowledge increase between the IMB and EAU groups (p = .59). The proportion of participants who transitioned from the contemplation to preparation motivational stages was greater in the IMB group than in the EAU group (p < .01). A significant difference in the rates of ketamine lapse during a one-year post intervention follow up was observed between the IMB (50%) and EAU (75%) groups (p < .01).

CONCLUSIONS

Interventions based on IMB principles may be more effective in supporting motivational stage transition and in prevention of lapses to ketamine use as compared to currently offered standard drug education programs. Policy makers should consider including IMB interventions in their rehabilitation programs addressing ketamine use problems.

Mis-anaesthetized society: expectancies and recreational use of ketamine in Taiwan

Background

The popularity of ketamine for recreational use has been increasing in Asia, including Taiwan. Still, little known about the pattern of ketamine expectancies and whether such patterns are related to ketamine use. This study aimed to examine whether the positive and negative ketamine expectancies are differentially associated with ketamine-using behavior, and whether such relationship may differ by early-onset use of tobacco or alcohol.

Methods

Participants were recruited using respondent-driven sampling (RDS) among regular tobacco and alcohol users, aged 18 to 50, residing in Taipei from 2007 to 2010. Totally 1115 participants (with an age distribution skewed to the right, median = 26; interquartile range: 22–32) had information on substance use and completed a 12-item ketamine expectancies questionnaire (with 6 positive and 6 negative statements). Using two axes of High and Low expectancies, the four combinations of binary positive and binary negative ketamine expectancies were created. Each participant’s drug-using experience was categorized into illicit drug naïve, exclusive ketamine use, polydrug ketamine use, or other illicit drug use. Using the weights in the network output by RDS Analysis Tool, multivariable logistic regression analysis was then conducted.

Results

The weighted prevalence was 2.4% for exclusive ketamine use, 9.0% for polydrug ketamine use, and 9.1% for the other illicit drug use. Ketamine users (11.4%) had greater positive expectancies and lower negative expectancies, particularly the combination of High Positive with Low Negative, as compared to the illicit drug-naïve or other illicit drug users. After adjustment for early-onset tobacco (or alcohol) use and sociodemographic characteristics, High Positive, Low Negative, and their combination of High Positive-Low Negative expectancies remained strongly associated with ketamine uses, without evidence of moderation from early-onset use of tobacco or alcohol.

Conclusions

Positive and negative ketamine expectancies were associated in opposite directions with ketamine use, independent of early-onset use of tobacco or alcohol. Our results indicate ketamine expectancies as possible targets for future intervention and prevention of ketamine use, with a less confrontational feedback on decreasing an individual’s positive expectancies is essential in preventing young people from the initiation of ketamine use.

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.

E-Cigarette Use in a Country With Prevalent Tobacco Smoking: A Population-Based Study in Taiwan

BACKGROUND

The different profiles of e-cigarette users in different age groups have seldom been investigated, particularly in populations facing a high prevalence of cigarette smoking. This study aims to examine the prevalence and correlates of e-cigarette use separately for adolescents and adults in nationally representative samples in Taiwan.

METHODS

Among 17,837 participants in the 2014 National Survey of Substance Use in Taiwan, 4445 were aged 12 to 17 years and 13,392 were aged 18 to 64 years. Individuals' lifetime tobacco use was divided into four groups: non-use, exclusive e-cigarette use, exclusive cigarette use, and dual use. Questions on sociodemographic features, use and problematic use of tobacco, alcohol, and other drugs, and psychosocial distress, among others, were administered using a computer-assisted self-interview on tablet computers.

RESULTS

Among lifetime users of e-cigarette (2.2% for adults and 0.8% for adolescents), 4.5% for adults and 36.6% for adolescents were exclusive e-cigarette users. From use of exclusive e-cigarettes to use of exclusive cigarettes to dual use, those usage groups were related to an increasing trend of adjusted odds ratios for use of other psychoactive substances, particularly problematic use of alcohol or drugs, and with more depressive symptoms. Two correlates were specific to e-cigarette use: alcohol use had stronger relationships with e-cigarette use among adolescents, and younger adults (18-34) were more likely to try e-cigarettes compared to older adults.

CONCLUSIONS

These results provide essential information regarding e-cigarette use in the general population, and future prevention strategies should account for its specific correlates in young people.

Cognitive profile of ketamine-dependent patients compared with methamphetamine-dependent patients and healthy controls

BACKGROUND

Ketamine has emerged as a major substance of abuse worldwide and has been listed with methamphetamine (METH) as two of the most widely available illicit substances in Taiwan. Only a few studies have examined the long-term consequences of chronic and heavy ketamine abuse. We compared the cognitive function of ketamine-dependent patients with that of METH-dependent patients and healthy controls.

METHODS

We recruited 165 participants (58 ketamine-dependent and 49 METH-dependent patients who sought treatment and 58 healthy controls) and evaluated them by using a cognitive test battery, the Brief Assessment of Cognition in Schizophrenia, with scores being estimated in reference to normative data in general population.

RESULTS

The ketamine-dependent patients had significantly poorer performance than did the controls in many cognitive tests, including verbal memory, motor speed, verbal fluency, and attention and processing speed, and the battery as a whole. METH-dependent patients exhibited poorer function in motor speed, verbal fluency, and attention and processing speed. The ketamine group performed poorer than did METH group in the domains of verbal memory, working memory, and attention and processing speed and the composite battery scores. A previous experience of ketamine-induced psychotomimetic symptoms, using higher doses of ketamine, and longer abstinence appeared to be associated with performance in some tests; however, the significance disappeared after multiple comparison correction.

CONCLUSIONS

The ketamine-dependent patients had impaired cognitive function, and METH-dependent patients exhibited intermediate performance between ketamine-dependent patients and healthy controls. Given the growing population of ketamine abusers, public education on the cognitive consequences should be provided.

The Development of Ecstasy Use Among Juvenile Offenders and Risk Factors for Predicting Heterogeneity: A Group-Based Approach

This study seeks to examine heterogeneity in developmental patterns of ecstasy use during adolescence and early adulthood among juvenile offenders and identify risk factors predicting development. Group-based trajectory modeling was utilized to elucidate heterogeneity in developmental patterns of ecstasy use. Multinomial logistic regression was utilized to identify covariates that affected the risk of assignment to groups elucidated in the trajectory model. A five-group model was found to best fit the ecstasy use data. Baseline measures of deviant peer association, self-control, other drug use, and race were identified as important risk factors predicting patterns of development. Risk of ecstasy use may be greatest for some juvenile offenders during critical periods of the life course and some social and personal characteristics that may elevate risk. Stability that is characteristic of self-control may be highly relevant for predicting persistent ecstasy use during adolescence and early adulthood.

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.

Adolescent substance use behavior and suicidal behavior for boys and girls: a cross-sectional study by latent analysis approach

BACKGROUND

Adolescent suicidal behavior may consist of different symptoms, including suicidal ideation, suicidal planning and suicidal attempts. Adolescent substance use behavior may contribute to adolescent suicidal behavior. However, research on the relationships between specific substance use and individual suicidal behavior is insufficient, as adolescents may not use only one substance or develop only one facet of suicidal behavior. Latent variables permit us to describe the relationships between clusters of related behaviors more accurately than studying the relationships between specific behaviors. Thus, the aim of this study was to explore how adolescent substance use behavior contributes to suicidal behavior using latent variables representing adolescent suicidal and substance use behaviors.

METHOD

A total of 13,985 adolescents were recruited using a stratified random sampling strategy. The participants indicated whether they had experienced suicidal ideation, planning and attempts and reported their cigarette, alcohol, ketamine and MDMA use during the past year. Latent analysis was used to examine the relationship between substance use and suicidal behavior.

RESULTS

Adolescents who used any one of the above substances exhibited more suicidal behavior. The results of latent variables analysis revealed that adolescent substance use contributed to suicidal behavior and that boys exhibited more severe substance use behavior than girls. However, there was no gender difference in the association between substance use and suicidal behavior.

CONCLUSION

Substance use behavior in adolescents is related to more suicidal behavior. In addition, the contribution of substance use to suicidal behavior does not differ between genders.

The validity and reliability of the Mandarin Chinese version of the drug abuse screening test among adolescents in Taiwan

Background

This study aimed to investigate the validity and reliability of the Mandarin Chinese version of the Drug Abuse Screening Test (DAST-20) among adolescents, as well as examining the test’s predictability with regard to the actual level of drug abuse.

Method

A total of 100 adolescent participants were recruited with their consent, in which 49 were current drug users and 51 were non-users. Based on the frequency of their drug use, participants who had used drugs at least once every week during the past year were classified as regular users (34 participants); participants who had not reached the regular use frequency of once every week during the past year were classified as occasional users (15 participants). All of the participants were required to answer a sociodemographic questionnaire, and undergo a DAST-20 (Mandarin Chinese version).

Results

The DAST-20, which has a high reliability with a Cronbach’s alpha of 0.88, and a construct validity accounting for 61.87% of the variance. The area under the receiver operating characteristics (ROC) curve was 0.96 between the users and nonusers, and 0.93 between the occasional users and non-occasional users. A cut-off of three points could identify 93.5% of the drug users and 88.9% of nonusers, whereas a cut-off of six points could identify 85.3% of the regular users and 92.4% of non-regular users.

Conclusions

The DAST-20 was the strongest predictor of adolescents who were regular users, occasional users, and non-users after controlling for other potential covariates. The Mandarin Chinese version of the DAST is simple to use and has a satisfactory validity and reliability. It is an effective screening tool for drug users among adolescents.

Residential environments, alcohol advertising, and initiation and continuation of alcohol consumption among adolescents in urban Taiwan: A prospective multilevel study

Background

Research indicates that place characteristics and the media environment are important contextual determinants of underage drinking behaviors in Western countries, but it is unknown whether these exposures influence adolescent alcohol consumption outside Western contexts, including in Asia׳s emerging global alcohol markets. Guided by the social ecological framework, we prospectively investigated the influences of place characteristics and alcohol advertising on initiation and continuation of alcohol consumption among adolescents in Taipei, Taiwan.

Methods

Data on individual-level characteristics, including alcohol use behaviors and perceived exposure to alcohol advertising, were obtained from two waves of a longitudinal school-based study through a stratified probability sampling method in 2010 (Grade 7/Grade 8, aged 13-14 years old) and 2011-2012 (Grade 9, aged 15 years old) from 1795 adolescents residing in 22 of 41 districts in Taipei. Data on district-level characteristics were drawn from administrative sources and Google Street View virtual audit to describe districts where adolescents lived at baseline. Hierarchical generalized linear models tested hypotheses about the associations of place characteristics and perceived alcohol advertising with underage drinking, with stratification by baseline lifetime alcohol consumption.

Results

Among alcohol-naïve adolescents, lower district-level economic disadvantage, a higher proportion of betel nut kiosks (a relatively unregulated alcohol source) compared to off-premises alcohol outlets, and exposure to television-based alcohol advertising predicted increased likelihood of alcohol initiation at one-year follow-up. Among alcohol-experienced adolescents, greater spatial access to off-premises alcohol outlets, and lower access to metro rapid transportation (MRT) and to temples were found to predict a subsequent increased likelihood of continued alcohol use. Parental drinking moderated the relationship between district-level violent crime and initiation of alcohol consumption.

Conclusions

These findings suggest that local social economic status, alcohol access, and institutional resource and individual media exposure affect underage drinking behaviors in Taiwan. We discuss potential public health implications for place-based interventions. Future research on place, media, and adolescent alcohol consumption in Asian contexts is warranted.

A family-oriented therapy program for youths with substance abuse: long-term outcomes related to relapse and academic or social status

OBJECTIVE

The abuse of illegal substances by youths in Taiwan has become a major public health issue. This study explores the outcomes (relapse rate and academic or social status) of a family-oriented therapy program conducted for substance-using youths who were referred by a judge to participate in it.

METHODS

The present study includes 121 participants categorized into three groups: 36 youths underwent a weekly ten-session outpatient motivational enhancement psychotherapy (MEP) group program; 41 youths participated in a program that combined the aforementioned MEP program with an additional weekly ten-session parenting skill training (PST) program for their guardians (MEP + PST group); and 44 adolescents who received standard supervision by the court served as the control group. All participants were followed-up for a maximum of 2 years.

RESULTS

Of the 121 participants (mean age: 16.1±1.1 years), 33.1% relapsed into substance use during the follow-up period. The probability of relapse did not differ significantly between the MEP group (36.1%) and the control group (40.9%), but the youths in the MEP + PST group (22.0%) were at a lower risk of relapse than the control group participants (adjusted hazard ratio =0.48, 95% confidence interval [CI] =0.21-1.09). By the end of the study follow-up period, participants in both the MEP group and the MEP + PST group were more likely to be attending school (MEP group: adjusted odds ratio [aOR] =6.61, 95% CI =1.60-27.35; MEP + PST group: aOR =8.57, 95% CI =1.94-37.82) or employed (MEP group: aOR =7.75, 95% CI =1.95-30.75; MEP + PST group: aOR =7.27, 95% CI =1.76-29.97), when compared to the control group.

CONCLUSION

This study revealed that a family-oriented treatment approach may be a more effective option for preventing youths' relapsing into substance abuse. In comparison to individuals who received standard supervision by the court, those who received MEP experienced a better school attendance or social outcome over the follow-up period.

Ceftriaxone reverses ketamine-induced lasting EEG and astrocyte alterations in juvenile mice

BACKGROUND

Ketamine, an N-methyl-d-aspartate receptor antagonist, is used as a pediatric anesthetic because of its favorable safety profile. It is also being investigated as an antidepressant. Unfortunately, ketamine causes adverse reactions including hallucinations and is associated with a high prevalence of abuse among adolescents. Although chronic ketamine use has been shown to produce cognitive impairments even years following cessation, little is known about its long-term consequences on adolescents. The beta-lactam ceftriaxone has been shown to attenuate alcohol withdrawal, and alleviate early brain injury and memory impairments following subarachnoid hemorrhage. However, its ability to reverse the effects of adolescent ketamine exposure is not known. Previous data indicate that ketamine causes a reduction in the number of Excitatory Amino Acid Transporter Type 2 (EAAT2)-containing astrocytes. Additionally, the beta lactam antibiotic ceftriaxone increased expression of EAAT2. As EAAT2 is a principal mechanism of glutamate clearance from the synapse, the current study tests the hypothesis that ceftriaxone may reverse functional consequences of ketamine exposure.

METHODS

We examined the effects of chronic ketamine in juvenile mice as well as reversal by ceftriaxone using electroencephalography (EEG). Subsequently, we assessed the effects of these treatments on markers of astrocyte proliferation, using Glial Fibrillary Acidic Protein (GFAP), and function, as evidenced by EAAT2.

RESULTS

Juvenile mice exposed to chronic ketamine showed lasting alterations in EEG measurements as well as markers of astrocyte number and function. These alterations were reversed by ceftriaxone.

CONCLUSIONS

Data suggest that ceftriaxone may be able to ameliorate ketamine-induced long-term disturbances in adolescent brains.

The use of psychotropic substances among students: The prevalence, factor association, and abuse

This detailed review analyzed the previously published studies related to the prevalence of psychotropic substances use, associated factors, and the misuse of the psychotropics among students. A comprehensive literature search covering six databases was performed. References from published articles and reports were extracted. This helped in identifying the available information on the use of psychotropic drugs. A total of 16 articles were included in this review. There is an upsurge of using psychotropics with the preceding years. More students are exposed to the risk of using psychotropic substances due to the multiple factors like stress, increased academic workload, etc. The misuse is found to be common with prescribed psychotropic substances. Students need to be aware of the bad outcomes of using psychotropic substances. Participation of every stakeholder to curb this menace needs to be emphasized. More extensive studies are required to know about the increasing prevalence, factors, and misuse of psychotropics.

Using Social Network as a Recruiting Tool for Research on Substance Use in the Taipei Metropolitan Area: Study Design, Implementation, and Epidemiological Estimates

Background

This study aimed to evaluate the practical utility of respondent-driven sampling (RDS) among regular tobacco and alcohol users in Taipei, Taiwan.

Methods

RDS was implemented from 2007 to 2010 to recruit seed individuals who were 18 to 50 years old, regular tobacco and alcohol users, and currently residing in Taipei. Each respondent was asked to refer up to five friends known to be regular tobacco smokers and alcohol drinkers to participate in the present study. Information pertaining to drug use was collected using an audio computer-assisted self-interview instrument. RDSAT software was used for data analyses.

Results

The prevalence estimates of illegal-drug-using behaviors attained equilibrium after three to five recruitment waves. Nearly one-fifth of the participants had ever used illegal drugs, of whom over 60% were polydrug users. The RDS-adjusted prevalences of illegal-drug-using behaviors among early-onset smokers were all two or three times higher than those among late-onset smokers.

Conclusions

Our results provided an empirical basis for the practicality and feasibility of using RDS to estimate illegal drug use prevalence among regular tobacco and alcohol users.

A family-oriented treatment program for youths with ketamine abuse and their caregivers: a pilot study in Taiwan

OBJECTIVE

The abuse of ketamine by youths has grown into a serious public health issue. However, a reliable and efficient treatment has still not been found for youths who abuse ketamine. This pilot study investigated the effects of a family-oriented treatment program for ketamine-using youths and their caregivers.

METHODS

To carry out this study, 42 youths with ketamine use (mean age 16.6±1.1 years) who were referred to take part in a 10-week treatment program based on motivational enhancement principles were selected, as were their principal caregivers (mean age 46.4±7.1 years), who were similarly referred to take part in a 10-week training program for parenting skills. The study had the youths complete the Chinese Craving Beliefs Questionnaire, the Adolescents' Behavior problem Scale, and the Family APGAR both immediately before and after the program. Likewise, the youths' caregivers completed the Family APGAR, the 12-item version of the Chinese Health Questionnaire, and the Parenting Stress Index.

RESULTS

Of the 42 youth-caregiver pairs that took part in this study, 37 (88%) completed the 10-week program and both sets of assessments. After the treatment, the participating youths' substance cravings declined (t=3.88, P<0.001), while family function, as perceived by the participating caregivers, significantly increased (t=2.22, P=0.033). The improvement in caregivers' perceptions of family function were positively related to the improvement of the caregivers' health status (r=-0.36, P=0.022).

CONCLUSION

According to its results, this pilot study submits that family-oriented treatment programs may be considered a potentially effective treatment option for youths who abuse ketamine. Additional studies with larger sample sizes, as well as longer follow-up periods, are necessary to verify whether this type of treatment also prevents youths using ketamine from relapsing.

Sexual initiation and emotional/behavioral problems in Taiwanese adolescents: a multivariate response profile analysis

This study aimed to investigate the relations of adolescent sexual experiences (particularly early initiation) to a spectrum of emotional/behavioral problems and to probe possible gender difference in such relationships. The 10th (N = 8,842) and 12th (N = 10,083) grade students, aged 16-19 years, participating in national surveys in 2005 and 2006 in Taiwan were included for this study. A self-administered web-based questionnaire was designed to collect information on sociodemographic characteristics, sexual experience, substance use, and the Youth Self-Report Form. For the sexually experienced adolescents, their sexual initiation was classified as early initiation (<16 years) or non-early initiation (16-19 years). Gender-specific multivariate response profile regression was used to examine the relationship between sexual experience and the behavioral syndromes. Externalizing problems, including Rule-breaking Behavior and Aggressive Behavior, were strongly associated with sexual initiation in adolescence; the magnitude of the association increased for earlier sexual initiation, especially for females. As to internalizing problems, the connection was rather heterogeneous. The scores on some syndromes, such as Somatic Complaints and Anxious/Depressed, were higher only for females with early or non-early sexual initiation whereas the score on Withdrawn, along with Social Problems that is neither internalizing nor externalizing, was lower for the sexually experienced adolescents than for the sexually inexperienced ones. We concluded that earlier sexual initiation was associated with a wider range of behavioral problems in adolescents for both genders, yet the increased risk with emotional problems was predominately found in females.

Effects of genetic variants of ADH1B and ALDH2 and social network on continued alcohol drinking among young adolescents in Taiwan

BACKGROUND

This study aimed (i) to evaluate the effects of genetic variants of ADH1B and ALDH2 and social network position on continued alcohol use in early adolescence, and (ii) to explore possible moderating role of pubertal development on genetic effects.

METHODS

The sample comprised 496 children who ever drank alcohol before the ages of 10-12. Information pertaining to sociodemographic background, pubertal development, parental drinking, alcohol and tobacco use, alcohol-metabolizing genes, and nominated best friends was collected in four waves of assessment. Polymorphisms of ADH1B (rs1229984) and ALDH2 (rs671) were genotyped. The latent class analysis was first used to characterize longitudinal alcohol use pattern, followed by the multinomial logistic regression analyses to assess its association with genes, pubertal development, and social network.

RESULTS

Three distinct classes of alcohol users (i.e. ex-drinkers, sporadic drinkers, and continued drinkers) were derived from alcohol-experienced children. Both alcohol-metabolizing genes appear to have protective effects, yet such relationships were only significant for youngsters in pre-to-early pubertal stage: the adjusted odds ratio (aOR) of ADH1B fast-genotype for sporadic drinkers was 0.46 and that of ALDH2 slow-genotype for both sporadic and continued drinkers was 0.47 and 0.42, respectively. Children having the bridge position in their peer network were more likely to be sporadic drinkers (aOR=4.15) and continued drinkers (aOR=3.16).

CONCLUSIONS

Our results illustrate a potential moderating effect of pubertal development on the protective influence of alcohol-metabolizing genes on subsequent alcohol use among alcohol-experienced children as well as the independent contribution of early life's social network to their alcohol involvement.

Peer influences on alcohol expectancies in early adolescence: a study of concurrent and prospective predictors in Taiwan

The effects of peers on three domains of alcohol expectancies through early adolescence were prospectively examined over 2 years. Information on pubertal development, parental drinking, peer characteristics, network structure, alcohol expectancies, and alcohol consumption was assessed in a three-wave longitudinal study of 779 6th graders (~12 years of age) randomly selected from northern Taiwan. Complex survey regression analyses, stratified by drinking experience in 6th grade, were performed to identify predictors of two positive (i.e., enhanced social behaviors and relaxation/tension reduction) and one negative alcohol expectancies (i.e., cognitive/behavioral deterioration) in 7th grade. The results showed that the effects of peer influence on adolescents' alcohol expectancies varied by prior drinking experiences and by expectancy domains. For the alcohol naive, recent exposure to peer drinking was significantly associated with positive and negative alcohol expectancies in grade 7, and this association was moderated by advanced pubertal development (ESBlate puberty: ßwt=0.55; ESBearly puberty: ßwt=-0.40; PRTRlate puberty: ßwt=0.01; PRTRearly puberty: ßwt=1.22; CBD late puberty: ßwt=-0.84; CBDearly puberty: ßwt=0.56). For the alcohol experienced, neither peer drinking nor pubertal development showed any significant links with alcohol expectancies. Occupying a bridge position was slightly linked with negative expectancy (ßwt=0.25). Concurrent drinking serves as a strong predictor for the endorsed alcohol expectancy in both groups, particularly for the domain of enhanced social behaviors. If these effects are confirmed, knowledge of the effect of interplay between peer factors and pubertal development on alcohol expectancies in early adolescence can provide effective targets in prevention programs.

Neurocognitive Profiles of Methamphetamine Users: Comparison of Those With or Without Concomitant Ketamine Use

OBJECTIVE

Methamphetamine (MAMP) and ketamine are neurotoxic drugs whose chronic use has been linked with a cognitive decline in some users. This paper aims to assess the possible effect of concomitant ketamine use on the neurocognitive performance of MAMP users.

METHODS

This study divides 42 MAMP users into MAMP users who use ketamine (MAMP+K, n = 16) and MAMP users who do not use ketamine (MAMP-K, n = 26). The performance of these two groups was compared using the Brief Assessment of Cognition in Schizophrenia (BACS), Conners' Continuous Performance Tests (CPT), the Wisconsin Card Sorting Test (WCST), the Iowa Gambling Task (IGT), and the Barratt Impulsiveness Scale (BIS).

RESULTS

In comparison to the MAMP-K group, the MAMP+K group showed worse performances in verbal fluency, executive function and composite score in BACS; worse performances in total errors, perseverative errors, nonperseverative errors and conceptual level response in WCST; and greater levels of total scores and novelty-seeking in BIS. Neither the attention function evaluated with CPT nor the decision-making behavior evaluated with IGT was associated with previous ketamine use.

CONCLUSION

This study detected worse executive function and higher impulsivity level among MAMP users with additional ketamine use versus their counterparts without ketamine use. Further studies with a longitudinal design and a large sample size are necessary to clarify the connection between cognitive deficits and concomitant use of MAMP and ketamine.

Gender differences in subjective discontinuation symptoms associated with ketamine use

Background

Recent substance abuse research indicates gender differences in the substance-related epidemiology, biological responses, progression to dependence, medical consequences and treatments. Studies exploring human sex-different responses to ketamine are rare and there has been no systemic survey of gender differences in ketamine use. Determining whether females are more susceptible than males to ketamine withdrawal symptoms and adverse effects is important, because it associated with treatment retention and outcome in drug users.

Methods

The Taiwanese juridical system has implemented a new regulation on ketamine in the year 2009. Ketamine users who are caught by the police, are mandated to attend an educational program. We recruited ketamine offenders from February 2010 to May 2012 at the Kunming branch of the Taipei City Hospital, where the educational classes are held. A designed questionnaire was performed to gather information about demographic characteristics, discontinuation symptoms, concomitant use of other substances, and subjective experience of memory impairment or urinary discomforts, and to compare the gender differences.

Results

A total of 1,614 ketamine users were surveyed and most of them were males (83.8%), with an average age of 26.3 ± 5.4 years. Female ketamine users presented significantly more discontinuation symptoms such as anxiety, dysphoria, and tremors compared with male users. 72.4% of total ketamine users smoked cigarettes concomitantly. Male ketamine users had a higher rate of concomitant betel nut use, while female ketamine users had a higher rate of concomitant hypnotic and alcohol use. 76% of total ketamine users reported cognitive impairment and 51.6% mentioned urinary symptoms. Furthermore, female ketamine users self-reported significantly greater levels of severity in cognitive impairment and urinary discomforts compared with male users. Less than 10% of total ketamine users in our study reported the desire to transfer for medical intervention or treatment, despite the high rates of discontinuation symptoms and negative physical side effects.

Conclusions

Gender differences were noted in the subjective experience of discontinuation symptoms, concomitant substance use, and severity of impairment related to ketamine use. However, the probable cause of the gender differences found in this study requires further investigation. We hoped our study will stimulate further research in this field.

The role of drug use sequencing pattern in further problematic use of alcohol, tobacco, cannabis, and other drugs

BACKGROUND

There has been considerable debate regarding what typically occurs after experimentation with drugs throughout the life of young people who used various drugs.

AIMS

To evaluate the clinical importance of the most common sequence for the first use of a drug by two models (the "gateway model" and the "alternative model", which is the most popular sequence for Brazilian university students according to a previous study) regarding the problematic use of alcohol, tobacco, cannabis and other illegal drugs, assessed by ASSIST.

METHOD

People who had already experimented with three or more drugs across different stages of the two models were selected from a representative sample of university students from 27 Brazilian capitals (n = 12 711).

FINDINGS

There were no differences regarding the problematic use of the most consumed drugs in Brazil (alcohol, tobacco and cannabis) between the models. Multiple drug seekers and violators had more problematic use of illegal drugs other than cannabis than individuals in the model sequence. However, in the case of violators, this was only evident in the alternative model.

CONCLUSIONS

Multiple drug seekers and violators deserve special attention due to their increased risk of problematic use of other illegal drugs.

Glutamate receptor antagonists as fast-acting therapeutic alternatives for the treatment of depression: ketamine and other compounds

The N-methyl-D-aspartate (NMDA) receptor antagonist ketamine has rapid and potent antidepressant effects in treatment-resistant major depressive disorder and bipolar depression. These effects are in direct contrast to the more modest effects seen after weeks of treatment with classic monoaminergic antidepressants. Numerous open-label and case studies similarly validate ketamine's antidepressant properties. These clinical findings have been reverse-translated into preclinical models in an effort to elucidate ketamine's antidepressant mechanism of action, and three important targets have been identified: mammalian target of rapamycin (mTOR), eukaryotic elongation factor 2 (eEF2), and glycogen synthase kinase-3 (GSK-3). Current clinical and preclinical research is focused on (a) prolonging/maintaining ketamine's antidepressant effects, (b) developing more selective NMDA receptor antagonists free of ketamine's adverse effects, and (c) identifying predictor, mediator/moderator, and treatment response biomarkers of ketamine's antidepressant effects.

Application of a sewage-based approach to assess the use of ten illicit drugs in four Chinese megacities

Sewage-based epidemiology was applied for the first time to a number of mainland Chinese megacities. The application monitored influents to 9 sewage treatment plants (STPs) to estimate the use of illicit drugs in Beijing, Guangzhou, Shenzhen, and Shanghai. Altogether, 11.4 million inhabitants were covered during September-October 2012. 24-h composite raw sewage samples were collected for 4 consecutive days at each STP. Each collected sample was analyzed for cocaine, benzoylecgonine, ecgonine methylester, methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine, 6-monoacetylmorphine, amphetamine, methamphetamine, ecstasy, mephedrone, methylenedioxypyrovalerone, 11-nor-9-carboxy-delta-9-tetrahydrocannabinol, ketamine, and norketamine. Through the analysis of these chemical residues, the use of amphetamine, cannabis, cocaine, ecstasy, heroin, mephedrone, methadone, methamphetamine, methylenedioxypyrovalerone and ketamine among Chinese urban inhabitants was monitored. The results obtained demonstrated in a quantitative way that the drug use patterns of Chinese are different from their European counterparts. Abuse of methamphetamine and ketamine was particularly noteworthy in China, while consumption of cocaine and ecstasy, the most popular drugs in Europe, was very low among the sampled Chinese inhabitants. Further, the use of most drugs demonstrated a geographical trend, since their use was much higher in the southern cities of Shenzhen and Guangzhou than it was in Beijing and Shanghai. Interestingly, the exclusive, but minor, metabolite of heroin, 6-monoacetylmorphine, was detected only sporadically. This would suggest that the use of heroin among Chinese urban users sampled in the study was low. Further, the patterns of drug use observed during the study are largely consistent with trends reported by the United Nations Office on Drugs and Crime. Overall, our study suggests that sewage-based epidemiology can readily be used to monitor the use of illicit drugs in those countries/regions where traditional means to monitor drug use patterns have only yielded limited or information of questionable reliability.

Use transition between illegal drugs among Brazilian university students

PURPOSE

The aim of the present study was to test whether the first use of an illicit drug increases the chance of first use of other illicit drugs.

METHOD

The transitions from the first use of a drug to the first use of another drug were analyzed. Comparisons were made between first drug users and non-users. Survival analysis methods were used to compare the cumulative probability of second drug use after adjusting for socio-demographic covariates and the intermediate use of alcohol and/or tobacco. A total of 12,721 Brazilian university students participated in this study.

RESULTS

Inhalants and marijuana were used prior to the use of several other drugs, whereas the opposite pattern was not found. Ecstasy was used before other drugs in several instances. Other well-examined drugs, such as amphetamines, cocaine and hallucinogens, were used both before and after other illicit drugs without any marked predominance for either of the two roles.

CONCLUSIONS

This study supports the role of the use of marijuana and inhalants almost exclusively before the use of other illicit drugs, whereas the use of ecstasy has an opposite role. These roles could be linked to the prevalence of lifetime use and whether individuals were at an earlier or later age during experimentation.

Ketamine use among regular tobacco and alcohol users as revealed by respondent driven sampling in Taipei: prevalence, expectancy, and users' risky decision making

The popularity of ketamine for recreational use among young people began to increase, particularly in Asia, in 2000. To gain more knowledge about the use of ketamine among high risk individuals, a respondent-driven sampling (RDS) was implemented among regular alcohol and tobacco users in the Taipei metropolitan area from 2007 to 2010. The sampling was initiated in three different settings (i.e., two in the community and one in a clinic) to recruit seed individuals. Each participant was asked to refer one to five friends known to be regular tobacco smokers and alcohol drinkers to participate in the present study. Incentives were offered differentially upon the completion of an interview and successful referral. Information pertaining to drug use experience was collected by an audio computer-assisted self-interview instrument. Software built for RDS analyses was used for data analyses. Of the 1,115 subjects recruited, about 11.7% of the RDS respondents reported ever having used ketamine. Positive expectancy of ketamine use was positively associated with ketamine use; in contrast, negative expectancy inversely associated with ketamine use. Decision-making characteristics as measured on the Iowa Gambling Task using reinforcement learning models revealed that ketamine users learned less from the most recent event than both tobacco- and drug-naïve controls and regular tobacco and alcohol users. These findings about ketamine use among young people have implications for its prevention and intervention.

Availability of convenience stores and adolescent alcohol use in Taiwan: a multi-level analysis of national surveys

AIM

To examine the association between alcohol in school environments and adolescent alcohol use over the previous 6 months.

DESIGN

A multi-level logistic regression analysis was performed of cross-sectional surveys conducted in 2004, 2005 and 2006.

PARTICIPANTS AND SETTING

A total of 52 214 students aged 11-19 years from 387 middle or high schools were selected from a nationally representative, multi-stage, stratified probability sampling across Taiwan.

MEASUREMENTS

Information on socio-demographic features and substance use experiences was collected using self-administered questionnaires. The alcohol in the environment was measured using the availability of convenience stores surrounding the schools. Using geographical information systems, the weighted numbers of convenience stores within 1 km, a 12-15-minute walk, of a school were calculated. The schools were later categorized into three subgroups via the tertile of nearby convenience stores.

FINDINGS

Considering the compositional characteristics, the availability of convenience stores was found to account for 1.5% of the school-level variance of youthful drinking. The odds ratios (95% confidence interval) of alcohol use over the previous 6 months among youth attending schools with medium and high availability were 1.04 (0.96-1.13) and 1.08 (1.00-1.17), respectively, with a P-value of 0.04 in the trend test.

CONCLUSION

The greater availability of convenience stores near a school is associated with an increased risk of alcohol use among adolescents over the previous 6 months.

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.

Proximal to distal correlates of the patterns of illicit drug use among night school students in Taiwan

This epidemiological study aimed to investigate illicit drug use by vocational high school night-class students in Taiwan to identify hypothesized proximal and distal factors associated with drug use patterns. Between September 2010 and January 2011, a randomized sample was drawn from 33 vocational high school night classes, enrolling 1079 students already employed outside campus. Subjects completed a validated self-reported questionnaire measuring proximal factors (biological, psychological, and behavioral) and distal factors (living with parents, parents' or siblings' use of legal substances, supervision by primary guardian, and perceived peer influence on drug use). Age, greater sensation-seeking behavior and legal substances use (i.e., tobacco and betel nuts) increased odds of being identified as experimental or regular users versus non-drug users. Higher rates of rule-breaking behavior were associated with increased odds of being identified as experimental users versus non-drug users. Among distal factors, only perceived peer influence on drug use was significantly associated with experimental and regular drug use. Proximal and distal factors were associated with drug use patterns among vocational high school night-class students. Influence factors identified may help vocational high school officials design effective illicit drug intervention programs for students with different drug use patterns.

Differential impact of IL-10 expression on survival and relapse between HPV16-positive and -negative oral squamous cell carcinomas

Human papillomavirus (HPV) is a risk factor in a subset of oropharyngeal cancer; however, the contribution of HPV in the malignancy of oral squamous cell carcinomas (OSCC) is not fully understood in Taiwanese. Herein, 61 patients with no risk factors and 117 patients with one or more risk factors were enrolled in this study. HPV16/18 infection rate in non-smokers, non-drinkers and non-betel quid chewers was higher than their counterparts. The development of HPV-infected cancer has been shown to be associated with interleukin-10 (IL-10) expression. To this end, IL-10 mRNA expression in OSCC tumors was evaluated by real-time RT-PCR. Data showed that HPV-positive patients had higher IL-10 mRNA levels than in HPV-negative patients. Kaplan-Meier and Cox-regression analysis indicated that the prognostic significance of IL-10 mRNA on overall survival and relapse free survival was only observed in HPV-positive OSCC, but not in HPV-negative OSCC. Mechanistically, the elevation of IL-10 by E6 was responsible for increased colony formation and migration capability in OSCC cells. Therefore, we suggest that IL-10 induced by E6 promotes cell growth and migration capability and consequent poor survival and relapse in HPV-positive OSCC.

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.

Illegal substance use among Italian high school students: trends over 11 years (1999-2009)

Purpose

To monitor changes in habits in drug use among Italian high school students.

Methods

Cross-sectional European School Survey Project on Alcohol and Other Drugs (ESPAD) carried out in Italy annually for 11 years (1999–2009) with representative samples of youth attending high school. The sample size considered ranges from 15,752 to 41,365 students and response rate ranged from 85.5% to 98.6%. Data were analyzed to obtain measures of life-time prevalence (LT), use in the last year (LY), use in the last 30 days (LM), frequent use. Comparisons utilized difference in proportion tests. Tests for linear trends in proportion were performed using the Royston p trend test.

Results

When the time-averaged value was considered, cannabis (30% LT) was the most, and heroin the least (2%) frequently used, with cocaine (5%), hallucinogens (2%) and stimulants (2%) in between. A clear gender gap is evident for all drugs, more obvious for hallucinogens (average M/F LY prevalence ratio 2, range 1.7–2.4, p<0.05), less for cannabis (average M/F LY prevalence ratio 1.3, range 1.2–1.5, p<0.05). Data shows a change in trend between 2005 and 2008; in 2006 the trend for cannabis use and availability dropped and the price rose, while from 2005 cocaine and stimulant use prevalence showed a substantial increase and the price went down. After 2008 use of all substances seems to have decreased.

Conclusions

Drug use is widespread among students in Italy, with cannabis being the most and heroin the least prevalent. Girls are less vulnerable than boys to illegal drug use. In recent years, a decrease in heroin use is overbalanced by a marked rise in hallucinogen and stimulant use.

To use or not to use: an update on licit and illicit ketamine use

Ketamine, a derivative of phencyclidine that was developed in the 1960s, is an anesthetic and analgesic with hallucinogenic effects. In this paper, the pharmacological and toxicological effects of ketamine are briefly reviewed. Ketamine possesses a wide safety margin but such a therapeutic benefit is somewhat offset by its emergence phenomenon (mind-body dissociation and delirium) and hallucinogenic effects. The increasing abuse of ketamine, initially predominantly in recreational scenes to experience a “k-hole” and other hallucinatory effects but more recently also as a drug abused during the workday or at home, has further pushed governments to confine its usage in many countries. Recently, urinary tract dysfunction has been associated with long-term ketamine use. In some long-term ketamine users, such damage can be irreversible and could result in renal failure and dialysis. Although ketamine has not yet been scheduled in the United Nations Conventions, previous studies using different assessment parameters to score the overall harms of drugs indicated that ketamine may cause more harm than some of the United Nations scheduled drugs. Some countries in Southeast and East Asia have reported an escalating situation of ketamine abuse. Dependence, lower urinary tract dysfunction, and sexual impulse or violence were the most notable among the ketamine-associated symptoms in these countries. These results implied that the danger of ketamine may have been underestimated previously. Therefore, the severity levels of the ketamine-associated problems should be scrutinized more carefully and objectively. To prevent ketamine from being improperly used and evolving into an epidemic, a thorough survey on the prevalence and characteristics of illicit ketamine use is imperative so that suitable policy and measures can be taken. On the other hand, recent findings that ketamine could be useful for treating major depressive disorder has given this old drug a new impetus. If ketamine is indeed a remedy for treating depression, more research on the risks and benefits of its clinical use will be indispensable.

Comparative epidemiology of betel nut use versus ecstasy use among Taiwanese adolescents: findings from a national survey

AIMS

To investigate whether variation may exist in betel nut- and ecstasy-involved adolescents in terms of sociobehavioral characteristics, the experience of psychoactive substance use, and behavioral/emotional problems.

METHODS

Students (n = 53,528) aged 12-18 sampled via stratified, multistage, random cluster sampling in 2004, 2005, and 2006 throughout Taiwan were categorized into four groups: betel nut- and ecstasy-naïve (n = 51,009), betel nut use only (n = 1965), ecstasy use only (n = 196), and use of both (n = 152). Participants completed a questionnaire with information on sociodemographic features, substance-use experiences, and the Chinese adaptation of the Youth Self Report.

RESULTS

Having a job, a larger weekly allowance, truancy, sexual experience, and externalizing behaviors were all in strong association with the involvement of either betel nut or ecstasy use. Compared with ecstasy-only users, betel nut-only users were more likely to be male, from the Eastern region of Taiwan, with initiation motivated by family members or friends, and having excess risks for Anxiety/Depression, Thought Problems, and Attention Problems. In contrast, ecstasy-only users were more likely to be female and involved in using other illegal drugs, with their initiation motivated by entertainment and with the drug use taking place in such settings.

CONCLUSIONS

The variation in the experience of psychoactive substance use and behavioral problems for betel nut and ecstasy users suggests the existence of subgroups of drug-using adolescents in Taiwan. The identification of such heterogeneity may guide the efforts to reduce substance use and develop subgroup-tailored preventive programs.