A Dual-Process Discrete-Time Survival Analysis Model: Application to the Gateway Drug Hypothesis

The gateway drug model is a popular conceptualization of a progression most substance users are hypothesized to follow as they try different legal and illegal drugs. Most forms of the gateway hypothesis are that “softer” drugs lead to “harder,” illicit drugs. However, the gateway hypothesis has been notably difficult to directly test—that is, to test as competing hypotheses in a single model that licit drug use might lead to illicit drug use or the reverse. This article presents a novel statistical technique, dual-process discrete-time survival analysis, which enables this comparison. This method uses mixture-modeling software to estimate 2 concurrent time-to-event processes and their effects on each other. Using this method, support for the gateway hypothesis in the National Longitudinal Survey of Youth, 1997, was weak. However, this article was not designed as a strong test of causal direction but more as a technical demonstration and suffered from certain technological limitations. Both these limitations and future directions are discussed.     

Stepping through the drug use sequence: longitudinal scalogram analysis of initiation and regular use.

Using a new technique for tracing the sequence of use over time, this study examined the pattern of drug involvement among 4,145 West Coast adolescents over the 4-year span from Grades 7-10. During the period covered, the mid- to late 1980s, we found no evidence that cocaine has become a gateway drug. However, the data provided some support for treating cocaine initiation as a separate stage that precedes the onset of hard drugs other than pills. The analysis also showed that increased involvement with legal drugs constitutes an important step in the transition to hard drug use for most adolescents. Weekly alcohol use followed marijuana use and preceded use of all other illicit drugs for Hispanic, White, and Black youth. However, it followed use of hard drugs for Asians. Weekly smoking formed a distinct stage between initial use of pills and other hard drugs for non-Hispanic Whites. The results underscore the importance of prevention efforts aimed at curbing the transition to regular use of alcohol and cigarettes, as well as their initial use.     

Parents who report using illicit drugs: findings and implications from the DRUGNET study

In recent years, a national discussion has emerged concerning what parents should tell their children about their own past drug use. DRUGNET is an ongoing, on-line survey of successful, healthy, adults who occasionally use illicit drugs. This paper reviews data from a subset of this survey, namely, those respondents who were parents with self-reported use of at least one illicit drug. The sample (n = 325) was predominantly white men who reported having above average education and household incomes. Their mental health as measured by the General Well-being Schedule was similar to the national norm. Respondents reported using drugs to manage parental stress and expressed concerns over how to communicate with their children and legal risks related to their own drug use. The limitations and the implications of these data are discussed.     

A Study of Some Factors Involved in Place Learning

Through the technique of Goodman's log linear method, longitudinal data are analyzed to clarify the relationship between depressive mood and illicit drug use among youths. A representative sample of adolescents (N = 8206) from New York State secondary schools was followed over one academic year. At one point in time, users of illicit drugs other than marihuana (multiple drug users) were significantly more depressed than either nonusers or users of marihuana only. Differing interactive relationships were found over time depending upon the drugs involved. Depressive mood was related to the onset of marihuana use among nonusers and to the termination of marihuana use among users. Depressive mood also predicted the use of other illicit drugs by marihuana users. While the beginning use of illicit drugs other than marihuana was positively associated with increased depressive mood, continued multiple drug use was related to reduced depressive mood.     

基于门户理论视角下的青少年物质成瘾

青少年物质成瘾行为受到普遍的关注, 成瘾物质滥用的机制一直是学者们探讨和研究的焦点。门户理论提出青少年发展成严重药物滥用者的过程存在顺序和阶段特征, 合法物质的使用会增加发展为非法药物使用的风险, 这种顺序效应得到了实证研究的支持。本研究在综述以往研究的基础上发现, 基于门户理论视角下青少年药物使用存在顺序效应, 但以往研究仍然存在一些不足, 例如药物使用顺序的不固定, 解释范围有限, 内在机制不清楚以及各种影响因素缺乏整合等。未来可以扩展研究对象和范围, 以深入研究顺序效应的内在机制。     

Are work stressors related to employee substance use? The importance of temporal context assessments of alcohol and illicit drug use

In this study, the author explored the relations of 2 work stressors (work overload and job insecurity) to employee alcohol use and illicit drug use. The primary goal was to explore the importance of temporal context (before work, during the workday, and after work) in the assessment of substance use compared with context-free (overall) assessments. Data were collected from a national sample of U.S. workers (N = 2,790) who took part in a broad cross-sectional survey on workplace health and safety. Consistent with past research, the results fail to support a relation between work stressors and overall measures of alcohol and illicit drug use. However, the results support the relation of work stressors to alcohol and illicit drug use before work, during the workday, and after work. These results provide support for both the stress-induced substance use and stress response dampening propositions of the tension-reduction hypothesis. When exploring the work environment as a potential cause of employee substance use, these results underscore the importance of measures that assess alcohol and illicit drug use in terms of their temporal relation to the workday.     

Substance abuse and violence: A review of the literature

Most alcohol and drug use occurs among persons who are not violent. However, alcohol and, to a lesser extent, illicit drugs are present in both offenders and victims in many violent events. The links between psychoactive substances and violence involve broad social and economic forces, the settings in which people obtain and consume the substance, and the biological processes that underlie all human behavior. In the case of alcohol, evidence from laboratory and empirical studies support the possibility of a causal role in violent behavior. Similarly, the psychopharmacodynamics of stimulants, such as amphetamines and cocaine, also suggest that these substances could play a contributing role in violent behavior. On the other hand, most real-world studies indicate that this relationship is exceedingly complex and moderated by a host of factors in the individual and the environment. In addition to psychopharmacological effects, substance use may lead to violence through social processes such as drug distribution systems (systemic violence) and violence used to obtain drugs or money for drugs (economic compulsive violence).     

Prenatal, perinatal, and early childhood risk factors and drug involvement in adolescence

This study examined prenatal, perinatal, and early childhood risk factors in relation to the etiology of adolescent involvement in cigarettes, alcohol, marijuana, and other illicit drugs. Over a span of 10 years, data were collected on 638 mainly White mother-child pairs at three points in time: at T1, when the children were 1 to 10 years old; at T2, when they were 9 to 18, and again at T3, when they were 11 to 20. Results showed that the early risks of an unwanted pregnancy and major illness were linked to all of the drug categories except "other illicit drugs." Aspects of mutual attachment in the mother-adolescent relationship were negatively correlated with adolescent drug use. Data on the interrelationship of the domains (i.e., sets of variables) of early risk factors and mother-adolescent relations supported an independent model with respect to cigarette and marijuana involvement, a finding in keeping with results showing that early risk did not significantly affect mother-adolescent relations. However, mother-adolescent protective factors were able to mitigate the impact of early risk factors on adolescent drug involvement.     

Neighborhood and Individual Factors in Marijuana and Other Illicit Drug Use in a Sample of Low-income Women

Few studies have systematically evaluated whether contextual variables differ in their ability to explain the use of different drugs in the same sample. Our objective was to examine correlates of use for different illicit drugs at the individual and neighborhood level in a tri-ethnic sample of low-income women, an underrepresented sample in drug research. Women 18–31 were recruited from a low-cost family planning clinic in southeast Texas from December 2001 to May 2003. Neighborhood level indicators of disadvantage, family structure, and nativity status from U.S. Census 2000 were linked with individual survey data. Multilevel logistic regression was used to examine the effect of individual and neighborhood level measures on lifetime use of marijuana only and of other illicit drugs in 594 women. Only individual level variables (younger age, non-Hispanic White ethnicity, not being married, greater peer acceptance of substance use) increased odds of exclusive marijuana use, controlling for neighborhood level factors. However, both neighborhood and individual level variables significantly predicted other illicit drug use. Residence in less disadvantaged neighborhoods, non-Hispanic White ethnicity, higher levels of education, greater acceptance of substance use by peers, and a larger number of perceived neighborhood problems increased odds of illicit drug use. Use of other illicit drugs with or without marijuana may be more closely tied to area level factors whereas factors driving exclusive marijuana use may not rely on localized structures to the same extent. Thus, community-level interventions may need to customize their approaches according to the type of drug use targeted. The implication of using neighborhood level variables in substance use research is also discussed.     

Adolescent precursors of intensity of marijuana and other illicit drug use among adult initiators

This study examined (a) adolescent psychosocial risk factors for frequency (intensity) of marijuana use and for other illicit drug use among those who started using these drugs in early adulthood (adult initiators) and (b) the protective role of parent-adolescent relations in reducing or preventing drug use when adolescents enter early adulthood. The study's participants were male and female youth from a longitudinal prospective study. The participants' mean ages were 17 and 22 years at late adolescence and early adulthood, respectively. Independent measures assessed personality, parental, peer, and self-drug-use factors during late adolescence; dependent measures assessed frequency of marijuana use and other illicit drug use during early adulthood for initiators of the respective drug categories. The authors found that intensity of marijuana use was directly associated with the personality, parental, and self-drug-use domains and indirectly associated with the peer domain. Intensity of other illicit drug use was directly associated with personality and self-drug use. Analyses also revealed that some parent-adolescent relations factors buffered the effects of risk factors for both marijuana and other illicit drug-use intensity, whereas others enhanced the effects of protective factors against other illicit drug-use intensity. The results indicate that there are both commonalities and differences in precursors of marijuana and other illicit drug-use intensity among initiators of these drugs during early adulthood.     

Adolescent Precursors of Intensity of Marijuana and Other Illicit Drug Use Among Adult Initiators

This study examined (a) adolescent psychosocial risk factors for frequency (intensity) of marijuana use and for other illicit drug use among those who started using these drugs in early adulthood (adult initiators) and (b) the protective role of parent-adolescent relations in reducing or preventing drug use when adolescents enter early adulthood. The study's participants were male and female youth from a longitudinal prospective study. The participants' mean ages were 17 and 22 years at late adolescence and early adulthood, respectively. Independent measures assessed personality, parental, peer, and self-drug-use factors during late adolescence; dependent measures assessed frequency of marijuana use and other illicit drug use during early adulthood for initiators of the respective drug categories. The authors found that intensity of marijuana use was directly associated with the personality, parental, and self-drug-use domains and indirectly associated with the peer domain. Intensity of other illicit drug use was directly associated with personality and self-drug use. Analyses also revealed that some parent-adolescent relations factors buffered the effects of risk factors for both marijuana and other illicit drug-use intensity, whereas others enhanced the effects of protective factors against other illicit drug-use intensity. The results indicate that there are both commonalities and differences in precursors of marijuana and other illicit drug-use intensity among initiators of these drugs during early adulthood.     

Prevalence and distribution of illicit drug use in the workforce and in the workplace: findings and implications from a U.S. national survey

This U.S. national study explored the overall prevalence, frequency, and distribution of illicit drug use in the workforce and in the workplace during the preceding 12 months. Illicit drug use in the workforce involved an estimated 14.1% of employed adults (17.7 million workers). Illicit drug use in the workplace involved an estimated 3.1% of employed adults (3.9 million workers). Illicit drug use in the workforce and in the workplace is not distributed uniformly in the employed population. At-risk, though circumscribed, segments of the U.S. workforce were identified with prevalence rates up to 55.8% for any use of illicit drugs and up to 28.0% for illicit drug use in the workplace. The implications of these data for future theoretical research and for management policy and practice are discussed.     

Illicit drug-related psychopharmacological violence: The current understanding within a causal context

This study reviews past research on psychopharmacological violence associated with illicit drug use within the criteria for causality. There appears to be prior evidence suggesting that illicit drug use and violent offending are related in certain circumstances; and other studies conclude that illicit drug use may be correlated with violent victimization. However, those studies that also adequately assessed temporal order do not strongly support an offender-based psychopharmacological link; and those that explored violent victimization are limited and inconclusive. More importantly, there are very few criminological efforts that assess the impact of illicit drug use on violence while also controlling for alternative individual-level causal explanations such as hormonal influences, genetic factors, variations in substance metabolism rates and intoxication decay, psychological functioning, concurrent alcohol and/or other drug use, gender differences, and illicit drug dosage. We offer suggestions for improving future assessments of illicit drug-related violent offending and victimization including capturing dosage and purity data, gauging temporal proximity of offender and victim intoxication relative to violent outcomes, and separating psychopharmacological factors (e.g., offender motivation and victim vulnerability) from economic and systemic circumstances.     

A comparison of the peers method and traditional methodologies, and risk behaviors in studies of the prevalence of drug consumption in a population of female, Chilean students

The present study investigates drug consumption and risk behaviors among female students between 8th and 12th grade in two communities in the city of Santiago, Chile. Based on studies of university populations, we hypothesize that the students' reports of their consumption of licit drugs will tend to be consistent with their actual use of said drugs using two methods to investigate consumption, while their consumption of illicit drugs will be susceptible, and will tend to be under-reported when evaluated through traditional self-report measures. In order to compare the two methods, a cross-sectional study was designed that would compare reported drug consumption, first using the peers method, and then by means of traditional self-report in a group of 350 students. The results show that women's reports of licit drug consumption converge using the two methods, while as earlier suggested, women's illicit drug consumption was found to be under-reported when traditional methodologies were used.     

Illicit Drug Use,Cognitive Distortions,and Suicidal Ideation Among Homeless Youth: Results From a Randomized Controlled Trial

Illicit drug use and cognitive distortions confer significant risks to youth suicidal thoughts and behaviors. However, there has been limited evidence regarding the efficacy of suicide prevention interventions with homeless youth, especially studies testing whether such interventions can reduce the risk for suicidal ideation associated with illicit drug use. Suicidal homeless youth (N = 150) between the ages of 18 to 24 years were recruited from a drop-in center. Youth were randomly assigned to Cognitive Therapy for Suicide Prevention (CTSP) + Treatment as Usual (TAU) or TAU alone. Youth reported their illicit drug use, cognitive distortions, and suicidal ideation 4 times over 9 months. A multiple-group multilevel structural equation model showed that higher illicit drug use at baseline predicted a slower reduction in cognitive distortions and suicidal ideation in the TAU group. These associations were not found in the CTSP + TAU group, suggesting an interruption of such risk from illicit drug use. Findings suggest that CTSP can reduce the risk of illicit drug use as a treatment barrier towards cognitive distortions and suicidal ideation among homeless youth, with implications to improve treatment efforts and to reduce premature mortality in a vulnerable population.     

等效性检验——结构方程模型评价和测量不变性分析的新视角

常用的结构方程模型拟合指数存在一定局限, 如χ ²以传统零假设为目标假设, 无法验证模型, 而RMSEA和CFI等描述性的拟合指数不具备推断统计性质, 等效性检验有效弥补了这些问题。首先说明等效性检验如何评价单个模型的拟合, 并解释其与零假设检验的不同, 然后介绍等效性检验如何分析测量不变性, 接着用实证数据展示了等效性检验在单个模型评价和测量不变性检验中的效果, 并与传统模型评价方法比较。     

Substance use risk across three generations: the roles of parent discipline practices and inhibitory control.

This study used 3 generations and 21 years of prospective data to test models of intergenerational transmission of substance use and substance use risk. Thus, the study extends prior studies in the field that have focused predominantly on substance abuse. The association between the grandparental generation's (G1 mother and father) and the parental generation's (G2 father) alcohol use and illicit drug use was hypothesized to be mediated by G2's poor inhibitory control. Additionally, G1's poor discipline of G2 was hypothesized to be directly associated with G2's substance use as well as to partially mediate the association between G1's substance use and G2's inhibitory control. In turn, G2's substance use in late adolescence was expected to be associated with its offspring's (G3) poor inhibitory control at age 3 years. Findings partially supported the predictions and varied by substance. For alcohol use, only cross-generational associations in use were found. For illicit drugs, both poor inhibitory control and poor discipline played some mediational role in cross-generational use.     

Substance use and abuse among children and teenagers

During the past several years, there has been a renewed national concern about drug abuse, culminating in the current "war on drugs." In this review, we emphasize that even though child or teenage drug use is an individual behavior, it is embedded in a sociocultural context that strongly determines its character and manifestations. Our focus is on psychoactive substances both licit (cigarettes and alcohol) and illicit (e.g., cannabis and cocaine). We feel that it is critical to draw a distinction between use and abuse of drugs and to do so from a multidimensional perspective that includes aspects of the stimulus (drug), organism (individual), response, and consequences. Our selective review of substance use and abuse among children and adolescents covers epidemiology (patterns and extent of drug use), etiology (what generates substance use), prevention (how to limit drug use), treatment (interventions with drug users), and consequences (effects and outcomes of youthful drug use).