Cristina B. Bares

Peer Attitudes Effects on Adolescent Substance Use: The Moderating Role of Race and Gender

We examined the relationship between adolescents’ perceptions of their close friends’ attitudes about substance use, and their own use of cigarettes, alcohol, and marijuana. Using data from the 2010 National Survey on Drug Use and Health, a multistage area probability sample sponsored by the Substance Abuse and Mental Health Services Administration (n = 17,865), we tested the direct and moderating effects of subgroups of race and gender on perceptions of adolescents’ close friends on past month substance use. Significant effects were found on peer attitudes influencing substance use for all race and gender subgroups. Close friends’ attitudes of indifference were associated with increased substance use and disapproval associated with reduced use, controlling for age, income, family structure, and adolescents’ own attitudes of risk of substance use. Significant moderating effects of peer attitudes on cigarette and marijuana use were found for both gender and race moderators. Conditional effects of the moderation by race were also examined for gender subgroups. The moderating effect of race on close friends’ attitudes impacting cigarette and marijuana use was stronger in magnitude and significance for females compared to males. Female marijuana and cigarette use was more influenced by close friends’ attitudes than males, and whites were more influenced by their close friends than Hispanics and blacks. White females are more susceptible to close friends’ attitudes on cigarette use as compared to white males and youth of other races. Implications for socially oriented preventive interventions are discussed.

The Association of Family and Peer Factors with Tobacco, Alcohol, and Marijuana Use Among Chilean adolescents in Neighborhood Context.

Research on adolescent use of substances has long sought to understand the family factors that may be associated with use of different substances such as alcohol, tobacco, and marijuana. However, scant attention has been focused on these questions in Latin American contexts, despite growing concerns about substance use among Latin American youth. Using data from a sample of 866 Chilean youth, we examined the relationship of family and neighborhood factors with youth substance abuse. We found that in a Latin American context, access to substances is an important predictor of use, but that neighborhood effects differ for marijuana use as opposed to cigarettes or alcohol. Age of youth, family and peer relationships, and gender all play significant roles in substance use. The study findings provide additional evidence that the use of substances is complex, whereby individual, family, and community influences must be considered jointly to prevent or reduce substance use among adolescents.

Knowledge of illness during childhood: Making distinctions between cancer and colds

Research on childrens knowledge of illnesses has largely concentrated on studying how children reason about common innocuous diseases. It is also important to uncover how children reason about more severe diseases, such as cancer, to be able to treat and communicate with children diagnosed with this disease. Several aspects of prevalent childhood cancers may challenge the intuitive theories that children hold about illness and can make cancer a difficult illness for children to understand. In the present study we assess knowledge of six dimensions (prognosis, internal, course, contamination, contagion, cause) of cancer and colds as a comparison illness. Healthy 5-, 7- and 10-year-olds, and adults were administered a yes/no and forced-choice questionnaire created to tap into six dimensions of two illnesses. Results indicate that 5-year-olds reason about cancer and colds in similar ways, but 7- and 10-year-olds begin to make a distinction between cancer and colds on some of the illness dimensions. Children in the youngest two age groups were found to think that cancer is just as contagious as colds but by age 10 children begin to think of cancer as a less contagious illness. Adults clearly differentiate between the two illnesses on almost all the dimensions.

An exercise in cost-effectiveness analysis: Treating emotional distress in melanoma patients

This study presents a retrospective assessment of a psychological intervention examined for its potential cost-effectiveness if implemented into standard care. It discusses (1) the cost of instituting a psychological intervention for distressed melanoma patients, (2) the effectiveness of that intervention for reducing distress when compared with a standard care group, and (3) the costs of providing the treatment as compared to costs of physician time to answer distress-driven questions as part of standard care. Although the per-minute cost of providing the psychological intervention was marginally greater than standard care, providing the intervention was significantly cheaper in terms of distress reduction. Inclusion of 60% payer reimbursement rates for the intervention further suggested that incorporating a psychological intervention into standard medical care for melanoma patients would potentially generate revenue.

Partner smoking and maternal cotinine during pregnancy: Implications for negative control methods

Background Comparison of the associations of maternal and mothers partner smoking with offspring outcomes is, in theory, a useful method for assessing whether there may be an intrauterine effect of tobacco exposure on these outcomes. However, this approach assumes that the effects of passive smoking from exposure to partner smoking during pregnancy are minimal. We evaluated this assumption using a biochemical measure of tobacco exposure in pregnant women. Methods Cotinine levels taken during the first trimester of pregnancy were measured in a sample of 3928 women from the Avon Longitudinal Study of Parents and Children. Median cotinine values were compared across categories of smoking heaviness (cigarettes per day) of the women during the first trimester and in non-smoking women by the smoking heaviness of their partner. Results Cotinine levels were substantially higher in women who smoked compared to non-smokers (range of medians across smoking heaviness categories: 900–5362 ng/ml versus 20 ng/ml, interquartile range (IQR) (0–63) for non-smokers). In contrast, cotinine levels in non-smoking women were only very weakly related to partner smoking status (range of medians in women with smoking partners: 34–69 ng/ml versus 12 ng/ml, IQR (0–48) in women with non-smoking partners). Conclusions Levels of tobacco exposure from partner smoking, as assessed by cotinine, were low in non-smoking pregnant women. This suggests that using mothers partners smoking as a negative control for investigating intrauterine effects is valid.

Differential item functioning due to gender between depression and anxiety items among Chilean adolescents

Background: Although much is known about the higher prevalence of anxiety and depressive disorders among adolescent females, less is known about the differential item endorsement due to gender in items of scales commonly used to measure anxiety and depression. Aims: We conducted a study to examine if adolescent males and females from Chile differed on how they endorsed the items of the Youth Self Report (YSR) anxious/depressed problem scale. We used data from a cross-sectional sample consisting of 925 participants (mean age = 14, SD 1.3, 49% females) of low to lower-middle socioeconomic status. Methods: A two-parameter logistic (2PL) IRT DIF model was fit. Results: Results revealed differential item functioning (DIF) by gender for six of the 13 items, with adolescent females being more likely to endorse a depression item while males were found more likely to endorse anxiety items. Conclusions: Findings suggest that items found in commonly used measures of anxiety and depression symptoms may not equally capture the true levels of these behavioural problems in adolescent males and females. Given the high levels of mental disorders in Chile and the surrounding countries, further attention should be focused on increasing the number of empirical studies examining potential gender differences in the assessment of mental health problems among Latin American populations to better aid our understanding of the phenomenology and determinants of these problems in the region.

Family and parenting characteristics associated with marijuana use by Chilean adolescents.

Objective Family involvement and several characteristics of parenting have been suggested to be protective factors for adolescent substance use. Some parenting behaviors may have stronger relationships with adolescent behavior while others may have associations with undesirable behavior among youth. Although it is generally acknowledged that families play an important role in the lives of Chilean adolescents, scant research exists on how different family and parenting factors may be associated with marijuana use and related problems in this population which has one of the highest rates of drug use in Latin America. Methods Using logistic regression and negative binomial regression, we examined whether a large number of family and parenting variables were associated with the possibility of Chilean adolescents ever using marijuana, and with marijuana-related problems. Analyses controlled for a number of demographic and peer-related variables. Results Controlling for other parenting and family variables, adolescent reports of parental marijuana use showed a significant and positive association with adolescent marijuana use. The multivariate models also revealed that harsh parenting by fathers was the only family variable associated with the number of marijuana-related problems youth experienced. Conclusion Of all the family and parenting variables studied, perceptions of parental use of marijuana and harsh parenting by fathers were predictors for marijuana use, and the experience of marijuana-related problems. Prevention interventions need to continue emphasizing the critical socializing role that parental behavior plays in their children’s development and potential use of marijuana.

E-Waste Informal Recycling: An Emerging Source of Lead Exposure in South America

BACKGROUND Primitive electronic waste (e-waste) recycling creates exposures to several hazardous substances including lead. In Uruguay, primitive recycling procedures are a significant source of lead exposure. OBJECTIVES The aim of this study was to examine lead exposure in blood lead levels (BLLs) in low-income children exposed to lead through burning cables. METHODS A sample of children and adolescents exposed to lead through burning cable activities were assessed at the Department of Toxicology in Montevideo, Uruguay, between 2010 and 2014. Soil lead levels of residences were taken shortly after their assessment. FINDINGS The final sample included 69 children and adolescents (mean age 7.89 years). More than 66% of participants had an additional source of lead exposure—manual gathering of metals—and <5% were exposed to lead through landfills or paint. Average BLLs at first consultation were 9.19 ug/dL and lower at the second measurement (5.86 μg/dL). Data from soil lead levels ranged from 650 to 19,000 mg of lead/kg of soil. The interventions conducted after the assessment included family education in the clinic and at home, indoor and outdoor remediation. We found a decrease in BLLs of 6.96 μg/dL. Older children had lower BLLs (r = −0.24; P =0.05). Statistical analyses also showed that children living in areas with higher soil lead levels had significantly higher BLLs (r = 0.50; P < 0.01). Additionally, we found greater BLLs from burning cable activities when children had been exposed to lead-based paint (r = 0.23; P < 0.1). CONCLUSION Among children exposed to e-waste recycling, the most common additional source of lead exposure was the manual gathering of metals. The average BLL among children and adolescents in this study is higher than the BLLs currently suggested in medical intervention. Future research should focus on exploring effective interventions to reduce lead exposure among this vulnerable group.

Racial differences in heritability of cigarette smoking in adolescents and young adults

INTRODUCTION Although epidemiologic studies suggest low levels of cigarette use among African American adolescents relative to White U.S. adolescents, it is not known whether this may be due to racial differences in the relative contribution of genes and environment to cigarette use initiation and progression to regular use. METHODS Using data from White (n=2665) and African American (n=809) twins and full siblings sampled in the National Longitudinal Study of Adolescents, we fitted age-, sex- and race-specific variance decomposition models to estimate the magnitude of genetic and environmental effects on cigarette use initiation and cigarette use quantity in Whites and African Americans across adolescence and adulthood. We employ a causal-contingent-common pathway model to estimate the amount of variance explained in quantity of cigarettes smoked contingent on cigarette use initiation. RESULTS African Americans had lower cigarette use prevalence from adolescence through adulthood, and used cigarettes less heavily than Whites. Race-specific causal-contingent-common pathway models indicate that racial differences in genetic and environmental contributions to cigarette use initiation and cigarette use quantities are not present in adolescence but appear in young adulthood. Additive genetic factors were an important risk factor for cigarette use initiation for White but not African American young adults and adults. CONCLUSIONS Genetic and environmental contributions for cigarette use are similar by race in adolescence. In adulthood, genes have a stronger influence for cigarette use among White adolescents while the influence of the environment is minimal. For African Americans, both genetic and environmental influences are important in young adulthood and adulthood.

Developmental Changes in Genetic and Shared Environmental Contributions to Smoking Initiation and Subsequent Smoking Quantity in Adolescence and Young Adulthood

BACKGROUND Few studies examining the genetic architecture of cigarette smoking have focused on adolescents or examined developmental changes in additive genetic, shared environment, and unique environmental influences on liability to initiate cigarette smoking and quantity of cigarettes smoked. The aim of this study was to add to the literature on liability to initiate and use cigarettes during adolescence using a nationally representative sample. METHOD Data for this study came from adolescent and young adult twin pairs (aged 14-33 years) from the National Longitudinal Study of Adolescent to Adult Health. We ran a series of developmental causal-contingent-common pathway models to examine whether additive genetic, shared, and unique environmental influences on liability to the initiation of cigarette use are shared with those on smoking quantity, and whether their contributions change across development. RESULTS We found evidence for a developmental shift in genetic and shared environmental contributions to cigarette use. Early in adolescence, genetic and environmental influences work independently on liability to cigarette smoking initiation and quantity of cigarettes smoked, but liability to these behaviors becomes correlated as individuals age into young adulthood. CONCLUSIONS These findings provide insight into the causal processes underlying the liability to smoke cigarettes. With age, there is greater overlap in the genetic and environmental factors that influence the initiation of cigarette smoking and quantity of cigarettes smoked.