Wastewater-based epidemiology to monitor 68 NPS/conventional drug use in Taipei metropolitan area in Taiwan during and after COVID-19 pandemic.

Amidst far-reaching COVID-19 effects and social constraints, this study leveraged wastewater-based epidemiology to track 38 conventional drugs and 30 new psychoactive substances (NPS) in northern Taiwan. Analyzing daily samples from four Taipei wastewater plants between September 2021 and January 2024-encompassing club reopenings, holidays, Lunar New Year, an outbreak, and regular periods-thirty-one drugs were detected, including 5 NPS. Tramadol, zolpidem tartrate, CMA, and MDPV were newly detected in Taiwanese sewage with frequency of 1.4 %- 89.0 %. Conventional drug use typically increased post-pandemic, aside from benzodiazepines and methadone. Methamphetamine showed 100 % frequency, indicating ongoing daily consumption despite COVID-19 measures. Methamphetamine and morphine's consumption dipped then rose around club reopening, hinting at limited access. The consumption trend of methadone appeared to compensate for the use of morphine. Ketamine and NPS demonstrated similar patterns throughout the entire period. NPS as party drugs seemed influenced by an unstable supply chain and complexities in implementation. Benzodiazepines, commonly abused alongside synthetic cathinones in Taiwan exhibited an opposing trend to NPS while aligned with acetaminophen, suggesting elevated stress and anxiety levels during the pandemic. No significant differences were observed in drug consumption between weekdays and weekends, potentially indicating that COVID-19 measures blurred the traditional distinctions between these timeframes. ENVIRONMENTAL IMPLICATION: New psychoactive substances refer to chemically modified variants of controlled drugs designed to mimic the effects of the original drugs while evading modern detection methods, categorizing them as hazardous materials. The study presents a sewage monitoring project conducted from 2021 to 2024, collecting samples from four WWTPs to analyze NPS and conventional drug trends during and after the COVID-19 pandemic. The findings uncovered connections between drug consumption patterns and pandemic-related policies. In light of the persistent drug abuse and their environmental presence, the results bear critical importance for both environmental and public health. We provide a thorough assessment of these relationships and prioritize areas for future research.

The use of premixed drugs in commodity packets in the population: prevalence and correlates revealed by the 2018 National Survey of Substance Use in Taiwan.

BACKGROUND: Administering premixed drugs in commodity packets was first reported in Asia in 2015, but there continues to be a dearth of related population-based data. This study aimed at examining (1) the prevalence of drug packet use in the population and (2) the sociodemographic profiles, particularly gender distribution, of drug packet users. METHODS: Data were derived from a survey of 18,626 Taiwanese civilians, aged 12-64 years, using stratified, multi-stage, random sampling in 2018. Participants anonymously completed a computer-assisted self-interview on tablet computers which covered the use and problematic use of illicit drugs/inhalants, prescription drugs and other psychoactive substances, among others. RESULTS: Approximately 1.46% of respondents had a lifetime use of illicit drugs, with drugs in commodity packets (0.18%) being ranked the fifth-most commonly used illicit drugs, higher than nitrous oxide (0.14%) and heroin (0.09%). Ten formats of drug packets were endorsed by users. Approximately 81.6% of persons with drug packet use had a lifetime use of other illicit drugs. The correlates of the use of drugs in commodity packets were similar to those of the exclusive use of other drugs except that there was a lack of gender differences in the use of drugs in commodity packets but not in the exclusive use of other drugs. CONCLUSION: Drugs in commodity packets have become a common way of administering illicit drugs in the population in Taiwan, and there were no gender differences among users. Our findings have implications for more efficient drug testing and culturally appropriate intervention for drug packet use.

Rapid and sensitive dilute-and-shoot analysis using LC-MS-MS for identification of multi-class psychoactive substances in human urine.

The emergence of new psychoactive substances currently exceeding a thousand is rapidly changing substance prevalence patterns and straining the methods used for detection, most of which are suitable only for a single class of substances. This study presents a rapid and facile dilute-and-shoot system operated in conjunction with an optimized liquid chromatographic separation system for the high-sensitivity detection of substances across a range of substance classes with 3 isotopes used only. The proposed method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) is able to identify 68 substance and their metabolites in urine samples as small as 50 µL. Optimal chromatographic conditions including 95% water/methanol ratio with 0.1% added formic acid and a prolonged LC gradient run-time (15 min) improved the peak shape of polar compounds and enhanced signal strength by 5%. Under 4-fold dilution, all analytes were within 80-120% of tolerance response levels, indicating that the matrix effect was insignificant. In experiments, the limit of detection (LOD) ranged from 0.05 to 0.5 ng mL-1, while the coefficient of determination (R2) was > 0.9950. The retention time shift of each peak remained at < 2% with an inter-day relative standard deviation (RSD) of 0.9-14.9% and intra-day RSD of 1.1%- 13.8%. The rapid dilute-and-shoot presents a high-sensitivity, significant stability, robustness and reproducibility without serious interference. To demonstrate the effectiveness of the system, 532 urine samples were collected from suspected drug abusers, and the proposed method was used for rapid analysis. Of these samples, 79.5% contained between one and twelve analytes, and 12.4% tested positive for new psychoactive substances, mostly derivatives of amphetamine and synthetic cathinones. The study presents a high-sensitivity analytic system that is capable of detecting substances from multiple classes and can be used for effective monitoring of substance prevalence in urine.

Monitoring Phthalates in Maternal and Cord Blood: Implications for Prenatal Exposure and Birth Outcomes.

Although many phthalates are endocrine-disrupting chemicals that are associated with adverse birth outcomes, the relationship between maternal phthalate exposure and birth outcomes is not yet conclusive. The objective of the present study was to investigate the association between prenatal exposure to phthalates in human maternal and cord blood and birth outcomes of the infants. Sixty-five mother-infant pairs were recruited in Taipei City and New Taipei City, and birth outcomes of the infants were recorded. Twelve phthalate metabolites were measured in maternal and cord blood samples. The mean of mono-ethyl phthalate, mono-isobutyl phthalate (MiBP), mono-n-butyl phthalate (MnBP), and mono-(2-ethylhexyl) phthalate (MEHP) was relatively higher than that of the other metabolites in both maternal and infant blood. There was a significant difference (p < 0.05) for mono-methyl phthalate (MMP) and MnBP between the maternal blood and cord blood of male infants. Mono-benzyl phthalate (MBzP), MMP, MiBP, and ∑di-2-ethylhexyl phthalate (∑DEHP) in maternal blood were inversely correlated with the anogenital index (AGI) of male infants, with a p value between 0.011 and 0.033. Mono-n-octyl phthalate, MMP, MiBP, MnBP, and MBzP were positively correlated with the AGI of female infants, with a p value between 0.001 and 0.034. Cord blood levels of MnBP, mono-(2-ethyl-5-oxohexyl)-phthalate, MEHP, and ∑DEHP were found to be inversely associated with head circumference in all the infants, adjusted for gestational age. Phthalate monoesters are potentially estrogenic and antiandrogenic chemicals. Longitudinal follow-up of the present study population could help clarify the long-term impact of phthalates on growth and the health effects of background exposure levels. Environ Toxicol Chem 2022;41:715-725. © 2022 SETAC.

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.

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.

Emergence of T cell immunosenescence in diabetic chronic kidney disease.

BACKGROUND: Type 2 diabetes is an important challenge given the worldwide epidemic and is the most important cause of end-stage renal disease (ESRD) in developed countries. It is known that patients with ESRD and advanced renal failure suffer from immunosenescence and premature T cell aging, but whether such changes develop in patients with less severe chronic kidney disease (CKD) is unclear. METHOD: 523 adult patients with type 2 diabetes were recruited for this study. Demographic data and clinical information were obtained from medical chart review. Immunosenescence, or aging of the immune system was assessed by staining freshly-obtained peripheral blood with immunophenotyping panels and analyzing cells using multicolor flow cytometry. RESULT: Consistent with previously observed in the general population, both T and monocyte immunosenescence in diabetic patients positively correlate with age. When compared to diabetic patients with preserved renal function (estimated glomerular filtration rate > 60 ml/min), patients with impaired renal function exhibit a significant decrease of total CD3+ and CD4+ T cells, but not CD8+ T cell and monocyte numbers. Immunosenescence was observed in patients with CKD stage 3 and in patients with more severe renal failure, especially of CD8+ T cells. However, immunosenescence was not associated with level of proteinuria level or glucose control. In age, sex and glucose level-adjusted regression models, stage 3 CKD patients exhibited significantly elevated percentages of CD28-, CD127-, and CD57+ cells among CD8+ T cells when compared to patients with preserved renal function. In contrast, no change was detected in monocyte subpopulations as renal function declined. In addition, higher body mass index (BMI) is associated with enhanced immunosenescence irrespective of CKD status. CONCLUSION: The extent of immunosenescence is not significantly associated with proteinuria or glucose control in type 2 diabetic patients. T cells, especially the CD8+ subsets, exhibit aggravated characteristics of immunosenescence during renal function decline as early as stage 3 CKD. In addition, inflammation increases since stage 3 CKD and higher BMI drives the accumulation of CD8+CD57+ T cells. Our study indicates that therapeutic approaches such as weight loss may be used to prevent the emergence of immunosenescence in diabetes before stage 3 CKD.

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.

The Co-Occurrence Of Frailty (Accumulation Of Functional Deficits) And Depressive Symptoms, And Its Effect On Mortality In Older Adults: A Longitudinal Study.

PURPOSE: The co-occurrence of frailty and depression in late life, the possibility for symptom reversal, their reciprocal relationship, and the effects on mortality have rarely been investigated. We aimed to examine the co-occurrence of frailty and depressive symptoms in late life, the possibility for symptom reversal, their reciprocal relationship, and the effects on mortality using all the information from a longitudinal study. PATIENTS AND METHODS: We used the Taiwan Longitudinal Study of Aging (TLSA) for this study. TLSA was initiated in 1989 and followed periodically. We included participants from 1989 to 2007, who had data on frailty and depressive symptoms. Frailty was assessed by accumulation of functional deficits in 6 dimensions including disease status, sensory dysfunction, balance, functional limitations, health risk behaviors, and life satisfaction. Depressive symptoms were measured with the Center for Epidemiologic Studies Depression Scale (CES-D). A multistate model with interval censoring was used to examine the transition between states of frailty with or without depressive symptoms, and finally to death. A mixed model was used to examine the relationships between frailty and depressive symptoms. RESULTS: The coexistence of frailty and depressive symptoms was associated with higher mortality. Individuals with depressive symptom had a lower probability of reversal to a better state. Previous depression score predicted current frailty, but the coefficient was smaller than that of previous frailty. Previous frailty predicted current depression score, and the coefficient was stronger than that of previous depression. CONCLUSION: Depressive symptoms increased the mortality and decreased the probability of reversal in the frail older adults.

Nonmedical prescription drug use of analgesics and sedatives/hypnotics in Taiwan: Results from the 2014 National Survey of Substance Use.

Nonmedical prescription drug use (NMPDU) has become a major public health issue but little is known in Asian populations. This study aimed to investigate the prevalence and correlates of NMPDU in Taiwan. Participants from the 2014 national survey of 17,837 individuals, aged 12 to 64 year, completed anonymously a computer-assisted self-interview. Past-year prescription drug use was divided into medical use only (MUO) and nonmedical use (NMU), defined as using the drug without a prescription, or more frequently, or in larger doses than prescribed. Problematic alcohol use was measured using the Alcohol Use Disorders Identification Test (AUDIT), problematic drug use using the 20-item Drug Abuse Screening Test (DAST), and depressive symptoms using the Center for Epidemiological Study-Depression (CES-D). The prevalence of past-year NMU was 3.02% for analgesics, 0.71% for sedatives/hypnotics, and 3.66% for either drug, with a very small overlap of NMU between analgesics and sedatives/hypnotics (0.07%). When individuals with NMU were compared to those without NMU (Non-NMU) and those with MUO, respectively, some correlates consistently identified, including young adulthood, tobacco smoking, alcohol drinking, and greater AUDIT's scores for analgesics, as well as hard drug use and greater DAST's scores for sedatives/hypnotics. NMU was associated with greater CES-D's scores for both analgesics and sedatives/hypnotics when compared to Non-NMU but not to MUO. Robust correlates of NMPDU could offer implications for development of prevention strategies of NMPDU.

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.

Construction of the REACHES climate database based on historical documents of China.

This paper describes the methodology of an ongoing project of constructing an East Asian climate database REACHES based on Chinese historical documents. The record source is Compendium of Meteorological Records of China in the Last 3000 Years which collects meteorology and climate related records from mainly official and local chronicles along with a small number of other documents. We report the digitization of the records covering the period 1644-1795. An example of the original records is translated to illustrate the typical contents which contain time, location and type of events. Chinese historical times and location names are converted into Gregorian calendar and latitudes and longitudes. A hierarchical database system is developed that consists of the hierarchies of domains, main categories, subcategories, and further details. Historical events are then digitized and categorized into such a system. Code systems are developed at all levels such that the original descriptive entries are converted into digitized records suitable for treatment by computers. Statistics and characteristics of the digitized records in the database are described.

Pediatric tracheotomy: A comparison of outcomes and lengths of hospitalization between different indications.

OBJECTIVES: To assess outcomes of pediatric tracheotomy and duration of associated hospital stay according to indications. SUBJECTS AND METHODS: In this retrospective study, subjects were 142 consecutive pediatric patients (<18 years old) who underwent tracheotomy at a tertiary referral medical center, National Taiwan University Hospital, in 1997-2012. Age, sex, indications, pre-operative status (oxygen demand, number of repeated intubations), and post-operative status (duration of weaning, length of hospital stay, mortality) were analyzed. RESULTS: The indications included craniofacial anomalies (n = 19, 13.4%), upper airway obstruction (n = 41, 28.9%), neurological deficit (n = 58, 40.8%), prolonged ventilation (n = 15, 10.6%), and trauma (n = 9, 6.3%). Ninety-one patients (64.1%) were successfully weaned off ventilation after tracheotomy (40% in the prolonged ventilation group). Total hospital stay and duration of ventilation before tracheotomy were longest in patients with craniofacial anomalies (150.9 ± 98.8 days, p = 0.004; 108.8 ± 88.2, p < 0.001). The early tracheotomy group had a shorter duration of post-tracheotomy mechanical ventilation support than the late tracheotomy group (14.4 ± 19.0, n = 49 vs. 34.9 ± 58.6, n = 80, p = 0.004). Decannulation was successful in 20 patients (14.1%), with the highest rate in the upper airway obstruction group (n = 14, 34.1%) and lowest in the prolonged ventilation group (none). Thirteen patients (9.2%) died during admission from causes unrelated to tracheotomy. CONCLUSION: Outcomes of pediatric tracheotomy and duration of hospitalization depend on indications. Children with craniofacial anomalies had earlier tracheotomy age and longer mechanical ventilation before tracheotomy resulted in longer hospitalization. Earlier tracheotomy can shorten the duration of post-tracheotomy mechanical ventilation in several conditions.

Differences in prevalence, socio-behavioral correlates, and psychosocial distress between club drug and hard drug use in Taiwan: Results from the 2014 National Survey of Substance Use.

BACKGROUND: This study examined variation between users of 'club' and 'hard' drugs in Taiwan in terms of prevalence of use and demographics and psychosocial characteristics. METHODS: Data were derived from a survey of 17,837 Taiwanese civilians, aged 12-64 years, using stratified, multi-stage, random sampling. Participants completed a computer-assisted self-interview on tablet computers which covered use of legal substances, sedatives/hypnotics and prescription analgesics; use of illicit drugs/inhalants, risky sexual experiences; expectations of drugs; and psychological distress. FINDINGS: Approximately 1.29% of respondents reported ever using an illicit drug in their lifetime; prevalence estimates of club drugs (mainly ketamine, marijuana, and ecstasy) were slightly higher than hard drugs (mainly methamphetamine and heroin). Concurrent use of legal substances, particularly problematic use of alcohol and tobacco, as well as non-medical use of prescription drugs, were strong correlates of illicit drug use in general, with club drug use exhibiting an extremely strong association with alcohol use. Club drug users were demographically different from hard drug users, including in terms of their gender, age, and level of educational attainment. They were also more likely to be divorced or widowed, to report risky sexual partnerships and more depressive symptoms than hard drug users. CONCLUSIONS: Our findings indicate drug type specific distinct psychosocial characteristics, which may warrant further attention in the design of treatment and intervention programs.

Television viewing and alcohol advertising with alcohol expectancies among school-aged children in Taiwan.

OBJECTIVES: This study is aimed to examine the strength of association between television watching and potential exposure to alcohol advertising with multidimensional alcohol expectancies in school-aged children. METHODS: A total of 779 4th (age 10) and 768 6th (age 12) grade students were recruited from 17 public elementary schools in northern Taiwan in 2006, with two waves of follow-up at 6 months apart. Self-administered questionnaires were used to collect information concerning individual characteristics, parental attributes, past-week screen time, drinking behaviors, and alcohol expectancies. Data of aired alcohol advertisements at baseline were obtained from the Nielsen Media Research Advertising Information Services; parenting styles were ascertained from the 1st follow-up. Alcohol Expectancies Questionnaire-Children version was used to measure alcohol expectancies (AEs) at baseline and the 2nd follow-up. RESULTS: Nearly 27% of students reported watching television for more than two hours per day and 58% watching television after 9 p.m. Dimension-related heterogeneity exists in the relationship between TV viewing and alcohol advertising with AEs. With statistical adjustment for covariates, spending more than two hours watching TV per day was associated with increased levels of positive AEs "Promoting Relaxation or Tension Reduction [PRTR]" (ß=1.52, 95% CI=0.92, 2.12; p<0.001); the exposure to alcohol advertising was associated with decline in negative AEs "Deteriorated Cognitive and Behavioral Function" (e.g., >8.0 ads: ß=-1.06, 95% CI=-1.66, -0.47, p<0.01). CONCLUSIONS: Greater screen time is associated with elevated positive expectancies of PRTR and alcohol advertising exposure is linked with lowered negative expectancies in late childhood. School-based anti-underage drinking programs may consider integrating the media literacy curriculum.

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.

Peers and social network on alcohol drinking through early adolescence in Taiwan.

OBJECTIVES: This study aims to identify peers and social network characteristics associated with drinking occasions through early adolescence. METHODS: The study sample of 1808 middle school students (aged 13-15 years) in northern Taiwan was collected via a two-wave longitudinal study of the Alcohol-Related Experiences among Children (AREC). Data concerning individual sociodemographics, family characteristics, peer influence, and alcohol drinking behaviors were collected via web-based self-administered questionnaire. Building upon the maximum of five friends nominated by young respondents at 7th grade, class-based social network was first constructed via the UCINET and Pajek; the network position (i.e., member, bridge, and isolate) for each student was subsequently ascertained. Complex surveys analyses and negative binominal regression models were used to evaluate concurrent and prospective relationship estimates. RESULTS: Effects of peers and social network were found to operate differentially by childhood alcohol experience. For the alcohol naïve youngsters, receiving higher peer's nomination at baseline was linked with subsequent increased drinking occasions (adjusted Incidence Rate Ratio [aIRR]=1.06; 95% CI=1.01-1.10), whereas having peers against alcohol drinking may reduce drinking occasions at 9th grade (aIRR=0.59; 95% CI=0.41-0.87). For the alcohol experienced youngsters, having parental alcohol offer, drinking peers, and attending classes of higher drinking norms may increase future drinking occasions by 90%, 80% and 44%, respectively. CONCLUSIONS: Our results demonstrated that parental alcohol offer, peer norms, and social network may affect adolescent drinking occasions differentially depending on childhood drinking experience. The findings have implications for the interventions to reduce alcohol consumption in underage population.

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.

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.