On the Importance of Coefficient Alpha for Measurement Research: Loading Equality Is Not Necessary for Alpha's Utility as a Scale Reliability Index.

The population relationship between coefficient alpha and scale reliability is studied in the widely used setting of unidimensional multicomponent measuring instruments. It is demonstrated that for any set of component loadings on the common factor, regardless of the extent of their inequality, the discrepancy between alpha and reliability can be arbitrarily small in any considered population and hence practically ignorable. In addition, the set of parameter values where this discrepancy is negligible is shown to possess the same dimensionality as that of the underlying model parameter space. The article contributes to the measurement and related literature by pointing out that (a) approximate or strict loading identity is not a necessary condition for the utility of alpha as a trustworthy index of scale reliability, and (b) coefficient alpha can be a dependable reliability measure with any extent of inequality in the component loadings.

Age of onset or age at assessment-that is the question: Estimating newly incident alcohol drinking and rapid transition to heavy drinking in the United States, 2002-2014.

Age-specific incidence estimates are important and useful facts in psychiatric epidemiology, but incidence estimation can be challenging. Methods artifacts are possible. In the United States, where the minimum legal drinking age is 21 years, recent cross-sectional field research on 12- to 25-year-olds applied conventional "age-at-assessment" approaches (AAA) for incidence estimation based on 12-month recall. Estimates disclosed unexpected nonlinear patterns in age-specific incidence estimates for both drinking onset and for transitioning from first drink to heavy drinking. Here, our aim is to draw attention to an "age of onset" (AOO) alternative to AAA approaches and to verify whether the AOO approach also discloses nonlinearity. Yearly data are from U.S. nationally representative samples drawn and assessed for National Surveys on Drug Use and Health, 2002-2014, with standardized audio computer-assisted self-interview assessments for drinking outcomes. Both AAA and AOO approaches show nonlinearities, with an unexpected dip in drinking incidence rates after age 18 and before the age 21 minimum legal drinking age. The AOO and the AAA approaches disclosed similar age-specific patterns. We discuss advantages of the AOO approach when nonlinear incidence patterns can be anticipated, but we conclude that the AAA approach has not created an artifactual nonlinear pattern.

Cannabis smoking and serum C-reactive protein: a quantile regressions approach based on NHANES 2005-2010.

BACKGROUND: Pre-clinical studies link cannabinoid-1 receptor activation to inflammation and atherosclerotic effects; anti-inflammation and immunosuppression seem to be mediated by cannabinoid-2 receptor activation. In this epidemiological study, we aim to present estimates on suspected cannabis-attributable immunomodulation as manifest in serum C-reactive protein (CRP) levels as non-specific inflammatory markers with interpretable clinical values. With strength of data from recent large nationally representative community sample surveys, the research approach illustrates value of a quantile regressions approach in lieu of the commonly used but relatively arbitrary cutpoints for CRP values. METHODS: The study population encompasses 20-59 year old participants from the National Health and Nutrition Examination Surveys, 2005-2010 (n=1115 recently active cannabis smokers and 8041 non-smokers, identified via confidential Audio Computer Assisted Self-Interviews). Age, sex, race, education, income-poverty ratio, alcohol consumption, and tobacco smoking also were measured, together with body mass index (BMI), which actually might be on a mediational path. Quantile regressions, with bootstrapping for variance estimation, made it possible to hold these covariates constant while estimating cannabis-CRP associations. RESULTS: Evidence suggesting possible cannabis-attributable immunomodulation emerges at CRP levels below the median (p<0.05). Whereas BMI might help explain a cannabis link with serum CRP, but BMI-stratified analyses disclosed no appreciable variation of the cannabis-CRP relationship across BMI subgroups. CONCLUSIONS: Extending pre-clinical research on cannabis-attributable immunomodulation, this study's CRP evidence points toward possible anti-inflammatory effects of cannabis smoking. More definitive evidence can be derived by combining pre-clinical research, studies of patients, and epidemiological research approaches.

Social rank and inhalant drug use: the case of lança perfume use in São Paulo, Brazil.

BACKGROUND: Lanca perfume (chloroform/ether) is an inhalant used mainly by higher social class students in Brazil. In light of the social and epidemiological features of lanca use, supply, and distribution, this investigation tests hypotheses about the degree to which use of inhalant lanca might be occurring in clusters, consistent with social sharing and diffusion, and might show a direct association with social rank even within the relatively privileged social context of private schools in a large mega-city of Latin America. METHODS: Epidemiologic self-report survey data were from a large representative sample of urban post-primary private school students in São Paulo city, Brazil, in 2008. Newly incident lanca use was studied, first with estimates of clustering from the alternating logistic regressions (ALR) and then with conditional logistic regressions to probe into the hypothesized direct social rank association. RESULTS: ALR disclosed a clustering of newly incident lanca users within private school classrooms (pairwise odds ratio (PWOR)=2.1; 95% CI=1.3, 3.3; p=0.002) as well as clusters of recently active lanca use (PWOR=1.9; 95% CI=1.1, 3.3; p=0.02). Occurrence of lanca use within private school classrooms was directly associated with social rank (odds ratio (OR)=0.2; 95% CI=0.1, 0.8; p=0.03 in the contrast of lowest socio-economic status (SES) versus highest SES strata within classrooms). Thereafter, study of other drugs disclosed similar patterns. CONCLUSIONS: The clustering estimates are consistent with concepts of person-to-person sharing of lanca within private school classrooms as well as other dynamic processes that might promote lanca clusters in this context. An observed direct association with social rank is not specific to lanca use. Direct SES estimates across a broad profile of drug compounds suggests causal processes over and above the more specific initially hypothesized social rank gradients in the lanca diffusion process. A novel facet of the evidence is greater occurrence of drug use among the higher social rank private school students, which should be of interest in the social science community.

Genome-environmental risk assessment of cocaine dependence.

Cocaine-associated biomedical and psychosocial problems are substantial twenty-first century global burdens of disease. This burden is largely driven by a cocaine dependence process that becomes engaged with increasing occasions of cocaine product use. For this reason, the development of a risk-prediction model for cocaine dependence may be of special value. Ultimately, success in building such a risk-prediction model may help promote personalized cocaine dependence prediction, prevention, and treatment approaches not presently available. As an initial step toward this goal, we conducted a genome-environmental risk-prediction study for cocaine dependence, simultaneously considering 948,658 single nucleotide polymorphisms (SNPs), six potentially cocaine-related facets of environment, and three personal characteristics. In this study, a novel statistical approach was applied to 1045 case-control samples from the Family Study of Cocaine Dependence. The results identify 330 low- to medium-effect size SNPs (i.e., those with a single-locus p-value of less than 10(-4)) that made a substantial contribution to cocaine dependence risk prediction (AUC = 0.718). Inclusion of six facets of environment and three personal characteristics yielded greater accuracy (AUC = 0.809). Of special importance was the joint effect of childhood abuse (CA) among trauma experiences and the GBE1 gene in cocaine dependence risk prediction. Genome-environmental risk-prediction models may become more promising in future risk-prediction research, once a more substantial array of environmental facets are taken into account, sometimes with model improvement when gene-by-environment product terms are included as part of these risk predication models.

An updated global picture of cigarette smoking persistence among adults.

BACKGROUND: Cross-national variance in smoking prevalence is relatively well documented. The aim of this study is to estimate levels of smoking persistence across 21 countries with a hypothesized inverse relationship between country income level and smoking persistence. METHODS: Data from the World Health Organization World Mental Health Survey Initiative were used to estimate cross-national differences in smoking persistence--the proportion of adults who started to smoke and persisted in smoking by the date of the survey. RESULTS: There is large variation in smoking persistence from 25% (Nigeria) to 85% (China), with a random-effects meta-analytic summary estimate of 55% with considerable cross-national variation. (Cochran's heterogeneity Q statistic = 6845; p < 0.001). Meta-regressions indicated that observed differences are not attributable to differences in country's income level, age distribution of smokers, or how recent the onset of smoking began within each country. CONCLUSION: While smoking should remain an important public health issue in any country where smokers are present, this report identifies several countries with higher levels of smoking persistence (namely, China and India).

Stigmatizing Clients with Mental Health Conditions: An Assessment of Social Work Student Attitudes.

Research suggests that stigma plays a major role in discouraging clients from participating in mental health treatment. Because social workers provide a significant amount of such services, this study investigates social work student stigma as a function of their willingness to treat clients with alcohol dependence, nicotine dependence, depression, and Alzheimer's disease. Students' held higher levels of stigma toward nicotine dependent clients and less toward those with depression. Personal histories of depression and student age - but not smoking or alcohol use - were predictive of higher stigma levels towards nicotine dependent clients. Implications for social work are discussed.

Sociodemographic correlates of transitions from alcohol use to disorders and remission in the São Paulo megacity mental health survey, Brazil.

AIMS: To evaluate sociodemographic correlates associated with transitions from alcohol use to disorders and remission in a Brazilian population. METHODS: Data are from a probabilistic, multi-stage clustered sample of adult household residents in the São Paulo Metropolitan Area. Alcohol use, regular use (at least 12 drinks/year), DSM-IV abuse and dependence and remission from alcohol use disorders (AUDs) were assessed with the World Mental Health version of the Composite International Diagnostic Interview. Age of onset (AOO) distributions of the cumulative lifetime probability of each alcohol use stage were prepared with data obtained from 5037 subjects. Correlates of transitions were obtained from a subsample of 2942 respondents, whose time-dependent sociodemographic data were available. RESULTS: Lifetime prevalences were 85.8% for alcohol use, 56.2% for regular use, 10.6% for abuse and 3.6% for dependence; 73.4 and 58.8% of respondents with lifetime abuse and dependence, respectively, had remitted. The number of sociodemographic correlates decreased from alcohol use to disorders. All transitions across alcohol use stages up to abuse were consistently associated with male gender, younger cohorts and lower education. Importantly, low education was a correlate for developing AUD and not remitting from dependence. Early AOO of first alcohol use was associated with the transition of regular use to abuse. CONCLUSION: The present study demonstrates that specific correlates differently contribute throughout alcohol use trajectory in a Brazilian population. It also reinforces the need of preventive programs focused on early initiation of alcohol use and high-risk individuals, in order to minimize the progression to dependence and improve remission from AUD.

Propensity score techniques and the assessment of measured covariate balance to test causal associations in psychological research.

There is considerable interest in using propensity score (PS) statistical techniques to address questions of causal inference in psychological research. Many PS techniques exist, yet few guidelines are available to aid applied researchers in their understanding, use, and evaluation. In this study, the authors give an overview of available techniques for PS estimation and PS application. They also provide a way to help compare PS techniques, using the resulting measured covariate balance as the criterion for selecting between techniques. The empirical example for this study involves the potential causal relationship linking early-onset cannabis problems and subsequent negative mental health outcomes and uses data from a prospective cohort study. PS techniques are described and evaluated on the basis of their ability to balance the distributions of measured potentially confounding covariates for individuals with and without early-onset cannabis problems. This article identifies the PS techniques that yield good statistical balance of the chosen measured covariates within the context of this particular research question and cohort.

Smoking estimates from around the world: data from the first 17 participating countries in the World Mental Health Survey Consortium.

OBJECTIVE: To contribute new multinational findings on basic descriptive features of smoking and cessation, based upon standardised community surveys of adults residing in seven low-income and middle-income countries and 10 higher-income countries from all regions of the world. METHODS: Data were collected using standardised interviews and community probability sample survey methods conducted as part of the WHO World Mental Health Surveys Initiative. Demographic and socioeconomic correlates of smoking are studied using cross-tabulation and logistic regression approaches. Within-country sample weights were applied with variance estimation appropriate for complex sample survey designs. RESULTS: Estimated prevalence of smoking experience (history of ever smoking) and current smoking varied across the countries under study. In all but four countries, one out of every four adults currently smoked. In higher-income countries, estimated proportions of former smokers (those who had quit) were roughly double the corresponding estimates for most low-income and middle-income countries. Characteristics of smokers varied within individual countries, and in relation to the World Bank's low-medium-high gradient of economic development. In stark contrast to a sturdy male-female difference in the uptake of smoking seen in each country, there is no consistent sex-associated pattern in the odds of remaining a smoker (versus quitting). CONCLUSION: The World Mental Health Surveys estimates complement existing global tobacco monitoring efforts. The observed global diversity of associations with smoking and smoking cessation underscore reasons for implementation of the Framework Convention on Tobacco Control provisions and prompt local adaptation of prevention and control interventions.

Risk management and post-marketing surveillance for the abuse of medications acting on the central nervous system: expert panel report.

The abuse and diversion of medications is a significant public health problem. This paper is part of a supplemental issue of Drug and Alcohol Dependence focused on the development of risk management plans and post-marketing surveillance related to minimizing this problem. The issue is based on a conference that was held in October 2008. An Expert Panel was formed to provide a summary of the conclusions and recommendations that emerged from the meeting involving drug abuse experts, regulators and other government agencies, pharmaceutical companies and professional and other non-governmental organizations. This paper provides a written report of this Expert Panel. Eleven conclusions and 11 recommendations emerged concerning the state of the art of this field of research, the regulatory and public health implications and recommendations for future directions. It is concluded that special surveillance tools are needed to detect the emergence of medication abuse in a timely manner and that risk management tools can be implemented to increase the benefit to risk ratio. The scientific basis for both the surveillance and risk management tools is in its infancy, yet progress needs to be made. It is also important that the unintended consequences of increased regulation and the imposition of risk management plans be minimized.

Toward a global view of alcohol, tobacco, cannabis, and cocaine use: findings from the WHO World Mental Health Surveys.

BACKGROUND: Alcohol, tobacco, and illegal drug use cause considerable morbidity and mortality, but good cross-national epidemiological data are limited. This paper describes such data from the first 17 countries participating in the World Health Organization's (WHO's) World Mental Health (WMH) Survey Initiative. METHODS AND FINDINGS: Household surveys with a combined sample size of 85,052 were carried out in the Americas (Colombia, Mexico, United States), Europe (Belgium, France, Germany, Italy, Netherlands, Spain, Ukraine), Middle East and Africa (Israel, Lebanon, Nigeria, South Africa), Asia (Japan, People's Republic of China), and Oceania (New Zealand). The WHO Composite International Diagnostic Interview (CIDI) was used to assess the prevalence and correlates of a wide variety of mental and substance disorders. This paper focuses on lifetime use and age of initiation of tobacco, alcohol, cannabis, and cocaine. Alcohol had been used by most in the Americas, Europe, Japan, and New Zealand, with smaller proportions in the Middle East, Africa, and China. Cannabis use in the US and New Zealand (both 42%) was far higher than in any other country. The US was also an outlier in cocaine use (16%). Males were more likely than females to have used drugs; and a sex-cohort interaction was observed, whereby not only were younger cohorts more likely to use all drugs, but the male-female gap was closing in more recent cohorts. The period of risk for drug initiation also appears to be lengthening longer into adulthood among more recent cohorts. Associations with sociodemographic variables were consistent across countries, as were the curves of incidence of lifetime use. CONCLUSIONS: Globally, drug use is not distributed evenly and is not simply related to drug policy, since countries with stringent user-level illegal drug policies did not have lower levels of use than countries with liberal ones. Sex differences were consistently documented, but are decreasing in more recent cohorts, who also have higher levels of illegal drug use and extensions in the period of risk for initiation.

Assessment of cocaine and other drug dependence in the general population: "gated" versus "ungated" approaches.

BACKGROUND: There is a need for large-scale epidemiological surveys to be (a) faithful to diagnostic specifications and (b) constrain time and participant burden associated with each section of a possibly lengthy interview. OBJECTIVE: To examine whether one "gating" approach devised for recent large-scale international psychiatric surveys results in a reduced number of identified cases of drug dependence and/or biases in estimated associations with background characteristics. DESIGN AND SETTING: Data from a recently released cross-sectional, nationally representative household survey, the United States National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) were analysed. PARTICIPANTS: Forty-three thousand ninety-three English speaking adults aged 18 years and over. MAIN OUTCOME MEASURES: Dependence upon cocaine and other illegal drug dependence, defined in two ways: "ungated" and "gated". "Ungated" dependence included all persons meeting criteria for DSM-IV dependence, without regard for DSM-IV drug abuse clinical features. "Gated" dependence required at least one feature of DSM-IV drug abuse. RESULTS: There was no statistically robust decrement in the estimated prevalence of cocaine or other drug dependence using a "gated" assessment. Patterns of association of cocaine dependence with background characteristics were not appreciably different when the gated and ungated approaches were applied. CONCLUSIONS: In panoramic mental health surveys, the inefficiency of an ungated approach must be balanced against the anticipated number of cases of dependence without associated social role impairments or harm. In this study, the reduction in the number of identified cocaine dependence cases appeared to be so small that even in a sample of over 40,000 participants, attenuation in population prevalence would prove difficult to detect.

Is depressed mood in childhood associated with an increased risk for initiation of alcohol use during early adolescence?

OBJECTIVE: Using prospective data, we tested the hypothesis that early depressed mood was associated with an increased risk for initiation of alcohol use. In addition, we examined whether these associations varied according to the youths' report that alcohol consumption occurred with or without parental permission. METHODS: The participants for these analyses were students, ages 9 to 13 years old, participating in a longitudinal study in an urban sample of public schools (n=2311). As part of the prospective annual assessments of the students, in 1990 through 1994, data on depressive mood and alcohol use were gathered. Logistic regression models were used to assess the association between the level of baseline depressed mood in 1990 and initiation of alcohol use between 1991 through 1994 in the sample of youth at risk for new onset drinking (n=1526). Other characteristics assessed in the analyses included age, sex, race-ethnicity, alcohol use by peers, neighborhood environment, and receipt of subsidized lunch. RESULTS: Higher level of early depressed mood was associated with an earlier and increased estimated risk of initiating alcohol use without parental permission for boys but not for girls. Depressed mood was not associated with alcohol use initiation that occurred with parental sanctions. CONCLUSIONS: Findings from the current study support the hypothesis that among urban youth, early depressed mood influences the initiation of alcohol consumption without parental permission for boys.

Adult smokers in Colombia: who isn't giving it up?

Without ongoing surveillance systems to assess tobacco product demand and exposure levels, many low and middle income countries monitor smoking via periodic cross-sectional surveys. In this article, we seek to update estimates for the prevalence of adult smoking in Colombia and contribute additional information useful for tobacco control initiatives. Data are from the 2003 Colombian National Study of Mental Health (NSMH). A national probability sample of 4426 adults (age 18-65) was assessed via a computer-assisted interview. An estimated 49% of the adult population had smoked at least once in their lifetimes; one in three adults (31%) had smoked regularly. Nearly half of regular smokers had been able to quit (44%; 95% CI=40-48). Several personal and smoking-related characteristics were associated with failing to quit: being a younger age, employed as compared to being a homemaker, and a history of daily use. Quitters and non-quitters were equivalent with respect to sex, educational status, and age of smoking onset. In conclusion, our findings describe the characteristics of regular smokers in Colombia and identify subgroups of non-quitters that may help guide tobacco control activities.

Hanging out with the wrong crowd: how much difference can parents make in an urban environment?

This longitudinal study of youths growing up in an urban area tests whether and by how much increased levels of supervision and monitoring by parents might influence levels of affiliation with delinquent and deviant peers--possibly our most sturdily replicated proximal determinant of early-onset illegal drug use and associated conduct problems in adolescence, aside from aggression and rule-breaking in childhood. Standardized interviews were used to assess parenting, affiliation with deviant peers, and other characteristics of the urban-dwelling youths in this epidemiologically defined sample (>70% African American heritage). Longitudinal analyses and generalized estimating equation (GEE) methods were used to estimate prospective relationships across the transition from late childhood into early adolescence. Results from the longitudinal analyses showed that higher levels of monitoring signaled later lower levels of affiliation with deviant peers, even with statistical adjustment for multiple covariates (beta=-0.04; 95% confidence interval [CI]=-0.07 to -0.02; P=.001). Closer parental supervision at ages 8-9 years was linked to subsequently lower levels of deviant peer affiliation (beta=-0.05; 95% CI=-0.08 to -0.01), and subsequent age-associated increases in levels of parental supervision from year to year were followed by decreases in levels of affiliation with deviant peers (beta=-0.12; 95% CI=-0.15 to -0.09). The main evidence from this study indicates that maintenance of parental supervision and monitoring through the transition from childhood to adolescence may yield important reductions in levels of affiliation with deviant peers, even in the context of our urban and sometimes socially disadvantaged community environments.