Association between adolescent substance use and obesity in young adulthood: A group-based dual trajectory analysis

Purpose

This study investigated whether and how trajectories of substance use in adolescence were associated with obesity trajectories in young adulthood. We hypothesized that: (1) exposure to persistent substance use throughout adolescence may heighten obesity risk in young adulthood; and (2) such associations may differ once gender, ethnicity, socioeconomic status, and obesity status in adolescence, are considered.

Methods

The study included 5141 adolescents from the child sample of the 1979 National Longitudinal Survey of Youth and utilized biennial data across the 12 assessments (1986–2008) to examine trajectories of substance use behaviors (i.e., cigarette smoking, alcohol use, and marijuana use) from ages 12 to 18 and obesity trajectories from ages 20 to 24. Group-based dual trajectory modeling was applied to examine sequential associations of trajectories of each type of substance use behavior with obesity trajectories.

Results

Three distinctive trajectory patterns were respectively identified for cigarette smoking, alcohol use, and marijuana use from ages 12 to 18, as well as for obesity status (BMI ≥ 30) from ages 20 to 24. Taking into account gender, ethnicity, socioeconomic status, and obesity status in adolescence, adolescents with the most problematic smoking trajectory (High-decreasing) were more likely to exhibit a High-obesity trajectory from ages 20 to 24. Also, adolescents with an Increasing marijuana use trajectory were more likely to exhibit an Increased obesity trajectory in young adulthood.

Conclusions

The current study demonstrates that adolescent substance use is associated with subsequent obesity in young adulthood. The associations appear to differ based on the type of substance use and patterns of use.     

Tobacco, alcohol, cannabis and other illegal drug use among young adults: the socioeconomic context

Background

Low socioeconomic position predicts risk of substance abuse, yet few studies tested the role of preexisting familial and individual characteristics.

Methods

Data come from the TEMPO (Trajectoires Epidémiologiques en Population) study (community sample in France, 1991–2009, n = 1103, 22–35 years in 2009) set up among offspring of participants of an epidemiological study (GAZEL). Past 12-month substance use was assessed in 2009 by self-completed mail survey: regular tobacco smoking, alcohol abuse (AUDIT), cannabis use, problematic cannabis use (CAST), other illegal drug use. Socioeconomic position was defined by educational attainment, occupational grade, employment stability and unemployment. Covariates included demographics (age, sex, relationship status, parenthood), family background (parental income, parental tobacco smoking, parental alcohol use), and juvenile characteristics (psychological problems, academic difficulties) measured longitudinally.

Results

35.8% of study participants were regular smokers, 14.3% abused alcohol, 22.6% used cannabis (6.3% had problematic cannabis use) and 4.1% used other illegal drugs. Except for alcohol abuse, substance use rates were systematically higher in individuals with low, rather than intermediate/high, socioeconomic position (age and sex-adjusted ORs from 1.75 for cannabis use to 2.11 for tobacco smoking and 2.44 for problematic cannabis use). In multivariate analyses these socioeconomic disparities were decreased, but remained statistically significant (except for illegal drugs other than cannabis).

Conclusions

Tobacco smoking, alcohol, cannabis and polysubstance use are common behaviors among young adults, particularly those experiencing socioeconomic disadvantage. Interventions aiming to decrease substance abuse and reduce socioeconomic inequalities in this area should be implemented early in life.     

Combined effects of alcohol and hepatitis C: A secondary analysis of alcohol use biomarkers and high-risk behaviors from two medication trials for alcohol dependence

Objectives

The goal of this secondary analysis was to examine the combined effects of HCV infection and recent alcohol use on baseline biologic markers of alcohol consumption in two outpatient medication trials for alcohol dependence. In addition, the relationship between Hepatitis C virus (HCV) infection and behavioral risk factors for HCV infection in these clinical populations were examined.

Methods

Data (n = 345) from two randomized, placebo-controlled trials of naltrexone and psychosocial treatment for alcohol dependence (Study I, n = 212) and comorbid alcohol and cocaine dependence (Study II, n = 133) were used to examine baseline measures of HCV risk behaviors (injection drug use, needle sharing), and biomarkers of alcohol use (AST, ALT, GGT and CDT) were compared by HCV serostatus first within each study and then across studies.

Results

Although groups had differing sociodemographic profiles (as indicated by race, marital status, level of education) subjects in Study I exhibited no statistically significant differences from the Study II cohort in HCV prevalence (12.7 vs. 20.0%, p = 0.07), lifetime history of injection drug use (13.8 vs. 22.0%, p = 0.74), lifetime history of needle sharing (9.1 vs. 18.0%, p = 0.62). As such, the data from both studies were analyzed together. Regardless of drinking status, HCV infection was significantly associated with an upward shift in the baseline level of ALT, AST, and GGT (p < 0.006 for all measures) and a downward shift in baseline CDT (p = 0.002). When using standard laboratory cutoff values to determine clinically significant elevations, HCV seropositivity was significantly associated with elevations in ALT, AST, GGT (p < 0.001), and with decreases in CDT (p = .002).

Conclusions

These data emphasize the importance of evaluating HCV infection and HCV risk behaviors at intake in medication trials for alcohol dependence and also raise questions regarding the use of cutoff scores for ALT, AST, GGT and CDT levels as biologic markers of alcohol use in subjects when HCV status is unknown.     

Longitudinal study of cognition among adolescent marijuana users over three weeks of abstinence

Background

Cognitive deficits that persist up to a month have been detected among adult marijuana users, but decrements and their pattern of recovery are less known in adolescent users. Previously, we reported cognitive deficits among adolescent marijuana users after one month of abstinence (Medina, Hanson, Schweinsburg, Cohen-Zion, Nagel, & Tapert, 2007). In this longitudinal study, we characterized neurocognitive changes among marijuana-using adolescents across the first three weeks of abstinence.

Method

Participants were adolescent marijuana users with limited alcohol and other drug use (n = 19) and demographically similar non-using controls (n = 21) ages 15–19. Participants completed a brief neuropsychological battery on three occasions, after 3 days, 2 weeks, and 3 weeks of stopping substance use. Abstinence was ascertained by decreasing tetrahydrocannabinol metabolite values on serial urine drug screens. Verbal learning, verbal working memory, attention and vigilance, and time estimation were evaluated.

Results

Marijuana users demonstrated poorer verbal learning (p < .01), verbal working memory (p < .05), and attention accuracy (p < .01) compared to controls. Improvements in users were seen on word list learning after 2 weeks of abstinence and on verbal working memory after 3 weeks. While attention processing speed was similar between groups, attention accuracy remained deficient in users throughout the 3-week abstinence period.

Conclusions

This preliminary study detected poorer verbal learning and verbal working memory among adolescent marijuana users that improved during three weeks of abstinence, while attention deficits persisted. These results implicate possible hippocampal, subcortical, and prefrontal cortex abnormalities.     

γ-Amino butyric acid and glutamate abnormalities in adolescent chronic marijuana smokers

Background

An increasing body of evidence from neuropsychological and neuroimaging studies suggests that exposure to marijuana throughout adolescence disrupts key cortical maturation processes occurring during this developmental phase. GABA-modulating pharmacologic treatments that elevate brain GABA concentration recently have been shown to decrease withdrawal symptoms and improve executive functioning in marijuana-dependent adult subjects. The goal of this study was to investigate whether the lower ACC glutamate previously reported in adolescent chronic marijuana smokers is associated with lower ACC GABA levels.

Methods

Standard and metabolite-edited proton MRS data were acquired from adolescent marijuana users (N = 13) and similarly aged non-using controls (N = 16) using a clinical 3T MRI system.

Results

The adolescent marijuana-using cohort showed significantly lower ACC GABA levels (−22%, p = 0.03), which paralleled significantly lower ACC glutamate levels (−14%, p = 0.01). Importantly, the lower ACC GABA and glutamate levels detected in the adolescent cohort remained significant after controlling for age and sex.

Conclusions

The present spectroscopic findings support functional neuroimaging data documenting cingulate dysfunction in marijuana-dependent adolescents. Glutamatergic and GABAergic abnormalities potentially underlie cingulate dysfunction in adolescent chronic marijuana users, and the opportunity for testing suitable pharmacologic treatments with a non-invasive pharmacodynamic evaluation exists.     

Common and unique parenting predictors of adolescent tobacco and alcohol use

Aim

The current study sought to identify unique and common demographic and parental predictors of adolescent tobacco and alcohol initiation behaviors.

Methods

A total of 1023 middle school students (Grades 6–8) and their parents from six Rhode Island schools were enrolled in a larger study on substance use initiation and progression, with the current sample representing those dyads with data at baseline and at a 12-month follow-up (n = 814 dyads). There was a relatively even split with regard to adolescent sex (n_females = 444; 55%). Comparisons were made between covariate and predictor associations with corresponding substance use behaviors (e.g., ever puffed a cigarette vs. ever sipped an alcoholic drink; ever smoked a whole cigarette vs. ever drank a full alcoholic drink).

Results

At the bivariate level, a host of demographic and parent-related variables were associated with each adolescent substance use behavior. Adolescent reports of parental monitoring variables were consistently more related to use than parent reports. In multivariate logistic regression analyses, adolescent reports of parental monitoring variables were more frequently associated with tobacco use behaviors than alcohol use behaviors. Tobacco use behaviors were more strongly predicted by perceived availability of tobacco than alcohol use behaviors were predicted by perceived availability of alcohol.

Conclusions

The distinctive predictors observed for cigarette versus alcohol use make it problematic for new and existing programs to assume that efforts targeting specific individual or parental characteristics will impact both substances with equivalent efficacy.     

5-Year trends in the intention to quit smoking amidst the economic crisis and after recently implemented tobacco control measures in Greece

Objectives

The objective of the present study was to explore the trends in the intention to quit smoking among adults in Greece between 2006 and 2011, a period characterized by financial instability and newly endorsed tobacco control initiatives.

Methods

Trend analysis of 3 representative national and cross-sectional surveys, ‘Hellas Health I’ (2006), “Hellas Health III” (2010) and Hellas Health IV (2011).

Results

Since 2006, the intention to quit smoking has significantly increased among both genders (33.3% [in 2006] to 42.4% [in 2011], p = 0.002), among respondents aged > 54 years (26.9% [in 2006] to 45.1% [in 2011], p = 0.019) and among residents of rural areas (26.4% [in 2006] to 46.7% [in 2011], p = 0.001). Both highest (32.1% [in 2006] to 49.4% [in 2011], p = 0.036) and lowest (31.7% to 46.0%, p = 0.021) socioeconomic (SE) strata showed an increase in the proportion of smokers who intend to quit. However, in 2011, quit attempts were more frequent (35.3%, p = 0.009) in smokers of high socioeconomic status. Moreover, smoking prevalence has significantly decreased (43.1% [in 2006] to 38.1% [in 2011], p = 0.023), mainly among men (52.4% to 45.7%, p = 0.037), respondents of low socioeconomic status (38.9% to 29.4%, p = 0.008) and residents of urban areas (45.2% to 37.9%, p = 0.005).

Conclusions

Over the past 5 years and possibly as a combined result of the implemented tobacco control policies and austerity measures, the intention to quit smoking has increased among all SE strata, however actual quit attempts were higher among those less disadvantaged. Further effort should be made to support quit attempts, especially among vulnerable populations.     

Risky cognitions associated with adolescent alcohol misuse: Moral disengagement,alcohol expectancies and perceived self-regulatory efficacy

Aim

To examine the longitudinal associations between moral disengagement, alcohol related expectancies, perceived self-regulatory efficacy and alcohol use amongst adolescents.

Design and participants

A total of 367 students (mean age = 13.1, SD = 0.51; 65% male) from five schools across Sydney, Australia took part in this longitudinal study. Participants completed a self-report questionnaire at four time points across an 18 month period which assessed their alcohol use, levels of moral disengagement, alcohol related expectancies and perceived self-regulatory efficacy to resist peer pressure to engage in transgressive behaviours.

Results

Over time, rates of binge drinking in the past three months significantly increased, but rates of drinking any alcohol in the past three months remained stable. As hypothesised, all three cognitions were independently and consistently associated with adolescent alcohol use and binge drinking over time, with the exception of perceived self-regulatory efficacy which was not associated with an increased risk of drinking any alcohol in the past three months when controlling for moral disengagement, alcohol expectancies, gender and age.

Conclusions

The current study is the first study to longitudinally map three distinct cognitive factors associated with adolescent alcohol use. Considering the alarming number of adolescents drinking at levels that place them at risk of significant harm, this study has provided important implications about cognitive factors that can be targeted to increase the accuracy of assessment and efficacy of prevention for alcohol misuse amongst adolescents.     

Socialization to binge drinking: A population-based,longitudinal study with emphasis on parental influences

Background

Binge drinking is associated with considerable harm. However, too little is known about socialization to this pattern of alcohol consumption.

Aim

To identify longitudinal predictors of young adult binge drinking, with an emphasis on possible parental influences.

Methods

A population-based prospective study, in which respondents (N = 2558) were surveyed from mid-adolescence until their late 20 s. The data set was linked to national registers. Data were collected on parental alcohol consumption, parental binge drinking and parental alcohol problems, as well as on other aspects of the family milieu. The respondents’ frequency of alcohol consumption was assessed, as well as a number of binge drinking measures: (i) frequency of intoxication episodes, (ii) frequency of consuming 5+ units, and (iii) “usual” consumption patterns of 5–6+ units, 7–9+ units, and 10+ units.

Results

A surprisingly high proportion of the sample met the criteria for binge drinking. After control for parental, peer and individual characteristics, parental binge drinking predicted respondents’ binge drinking, using all definitions, at age 28 years (p < .001). Parental frequency of alcohol consumption predicted frequency of alcohol consumption in their offspring at age 28 (p < .001).

Conclusion

The findings suggest a socialization pattern of alcohol role modeling from parents to offspring. The findings are also consistent with genetic research showing alcohol use to have moderate heritability. We may witness new binge drinking cultures in Norway, but binge drinking patterns also seem to echo parental influences.     

The aftermath of public housing relocation: Relationship to substance misuse

Introduction

Several cross-sectional studies have examined relationships between neighborhood characteristics and substance misuse. Using data from a sample of African-American adults relocating from US public housing complexes, we examined relationships between changes in exposure to local socioeconomic conditions and substance misuse over time. We tested the hypothesis that adults who experienced greater post-relocation improvements in local economic conditions and social disorder would have a lower probability of recent substance misuse.

Methods

Data were drawn from administrative sources to describe the census tracts where participants lived before and after relocating. Data on individual-level characteristics, including binge drinking, illicit drug use, and substance dependence, were gathered via survey before and after the relocations. Multilevel models were used to test hypotheses.

Results

Participants (N = 172) experienced improvements in tract-level economic conditions and, to a lesser degree, in social disorder after moving. A one standard-deviation improvement in tract-level economic conditions was associated with a decrease in recent binge drinking from 34% to 20% (p = 0.04) and with a decline in using illicit drugs weekly or more from 37% to 16% (p = 0.02). A reduction in tract-level alcohol outlet density of >3.0 outlets per square mile predicted a reduction in binge drinking from 32% to 18% at p = 0.05 significance level.

Discussion

We observed relationships between improvements in tract-level conditions and declines in substance misuse, providing further support for the importance of the local environment in shaping substance misuse. These findings have important implications for public housing policies and future research.     

Biological markers of problem drinking in homeless patients

Objective

In the search for optimal biomarkers of excessive drinking, a central limitation has been the lack of sensitivity of measures. Many patients have apparently normal values of liver markers despite a considerable alcohol intake. This study aimed to test a novel combined indicator of alcohol drinking.

Material and methods

Concentrations of carbohydrate-deficient transferrin (%CDT), γ glutamyl transferase (γGT), aspartate aminotransferase (ASAT), and mean corpuscular volume (MCV), together with a combined index of the %CDT and γGT, the Antilla Index (AI), were studied in 104 homeless patients with (n = 87) or without (n = 24) problem drinking according to the Fast Alcohol Screening Test.

Results

Concentrations of all markers were significantly higher in the alcoholic patients than in other homeless patients. The best agreement between liver markers and self-reported status was found between the combined %CDT and γGT index (kappa = 0.61, p < 0.001, sensitivity = 63%, specificity = 94%).

Conclusions

The combined AI is a relatively efficient measure of current drinking in homeless populations.     

Binge drinking trajectory and neuropsychological functioning among university students: A longitudinal study

Background

Adolescence is a time of considerable neurodevelopment. Binge drinking (BD) during this period increases the vulnerability to its neurotoxic effects. This longitudinal study aimed to investigate the relationship between BD trajectory over university years and neuropsychological functioning.

Methods

Cohort-study. Two-year follow-up. A total of 89 university students were assessed: 40 Non-BD (at Initial and Follow-up), 16 Ex-BD (BD at Initial but not at Follow-up) and 33 BD (at both times). Neuropsychological assessment of working memory, episodic memory and executive abilities was carried out during their first (Initial) and third (Follow-up) academic year at the University of Santiago de Compostela.

Results

BD subjects performed less well on the Wechsler Memory Scale-III (WMS-III) Logical Memory Subtest (immediate theme recall, P = .034; delayed theme recall, P = .037; and percent retention, P = .035) and committed more perseverative errors on the Self-Ordered Pointing Task (SOPT) (P = .021) than Non-BD. There were no differences between Ex-BD and Non-BD.

Conclusions

Binge drinking trajectory during adolescence is associated with neuropsychological performance. Persistent BD, but not Ex-BD, is associated with verbal memory and monitoring difficulties. This is compatible with the hypothesis that heavy alcohol use during adolescence may affect cognitive functions that rely on the temporomesial and dorsolateral prefrontal cortex.     

Effect of motivational interviewing on reduction of alcohol use

Background

Methadone-maintained (MM) clients who engage in excessive alcohol use are at high risk for HIV and hepatitis B virus (HBV) infection. Nurse-led hepatitis health promotion (HHP) may be one strategy to decrease alcohol use in this population.

Objective

To evaluate the impact of nurse-led HHP, delivered by nurses compared to motivational interviewing (MI), delivered by trained therapists in group sessions or one-on-one on reduction of alcohol use.

Methods

A three-arm randomized, controlled trial, conducted with 256 MM adults attending one of five MM outpatient clinics in the Los Angeles area. Within each site, moderate-to-heavy alcohol-using MM participants were randomized into one of three conditions: (1) nurse-led hepatitis health promotion group sessions (n = 87); (2) MI delivered in group sessions (MI-group; n = 79), or (3) MI delivered one-on-one sessions (MI-single, n = 90).

Results

Self-reported alcohol use was reduced from a median of 90 drinks/month at baseline to 60 drinks/month at 6-month follow-up. A Wilcoxon sign-rank test indicated a significant reduction in alcohol use in the total sample (p < .05). In multiple logistic regression analysis controlling for alcohol consumption at baseline and other covariates, no differences by condition were found.

Discussion

As compared to two programs delivered by MI specialists, a culturally-sensitive and easy to implement nurse-led HHP program produced similar reductions in alcohol use over 6 months. Employing nurse-led programs may allow cost savings for treatment programs as well as a greater integration of alcohol reduction counseling along with a more comprehensive focus on general health-related issues than previously conducted.     

Intentions to quit smoking among youth in substance abuse treatment

Introduction

Smoking cessation interventions for adolescents in substance abuse treatment have shown promise. However, a better understanding of the correlates of substance use disordered (SUD) youths’ intentions toward smoking cessation will help tailor cessation interventions to this population. The current study examined tobacco use, smoking-related self-efficacy, substance use and intentions to quit using alcohol and illicit drugs as correlates of intentions to quit smoking among youth in SUD treatment.

Methods

Participants were 178 adolescents who were in inpatient (n = 90) or outpatient (n = 88) SUD treatment and had smoked at least once in the past 30 days. The sample was 44% female, 72% non-Hispanic Caucasian, with a mean age of 16.2 years (SD = 1.2). Participants rated the likelihood that they would be nonsmokers in the next year (9-point scale).

Results

SUD youth intention to quit smoking averaged 4.9 out of 10 (SD = 3.2), comparable to intention to quit drinking (M = 5.3, SD = 3.6), but lower than their intention to quit using drugs (M = 6.0, SD = 3.4). Teens’ intentions to quit smoking were associated with nicotine dependence (r = −.30, p < .01) and smoking cessation related self-efficacy (r = .36, p < .01), but not with pretreatment substance use severity (r = −.15). Controlling for nicotine dependence, teens’ intentions to quit smoking were positively related to smoking cessation self-efficacy (pr = .26, p < .01) and intention to quit using illicit drugs (pr = .15, p < .05), but unrelated to intention to quit drinking.

Discussion

Findings highlight the appropriateness of addressing adolescent tobacco use during SUD treatment, but emphasize the importance of assessing intention and other cognitions for each substance, as they may differ markedly.     

Vitamin D deficiency in alcohol-use disorders and its relationship to comorbid major depression: A cross-sectional study of inpatients in Nepal

Background

Mounting evidence suggests that deficiency of vitamin D may be associated with major health problems, including alcohol-use disorders (AUD) and major depression (MD). This study aimed to identify the vitamin D status of Nepalese inpatients with an AUD. We explored socio-demographic and alcohol-use related correlates and the relationship between vitamin D deficiency and comorbid MD.

Methods

A cross-sectional study was conducted on AUD inpatients (N = 174) at eight alcohol/drug treatment centres around Kathmandu. Structured questionnaires were administered to assess the socio-demographic and alcohol-use parameters and to establish DSM-IV diagnoses of AUD and MD. Vitamin D deficiency was defined as a serum 25-hydroxyvitamin D (25(OH)D) concentration of <50 nmol/L.

Results

The prevalence of vitamin D deficiency was 64%. Higher age, having a stable job or business, shorter time since last alcohol intake and winter serum samples were related to having lower 25(OH)D levels. Several features of AUD severity were associated with low vitamin D levels: guilt about drinking, using alcohol as eye-opener, and history of relapse after alcohol treatment (p ≤ 0.03). Patients with a comorbid major depression, in particular secondarily depressed cases, were less likely to have vitamin D deficiency (X² = 6.8; p = 0.01).

Conclusions

This study confirms high rates of vitamin D deficiency in alcohol treatment sample and shows a positive association between vitamin D deficiency and severity of alcohol-use disorders. Competing risk and other confounders may help explain the vitamin D status among patients with alcohol-use disorders and comorbid major depression.     

Brief motivational enhancement intervention to prevent or reduce postpartum alcohol use: A single-blinded,randomized controlled effectiveness trial

Aims

The aim of this study is to assess the effect of brief motivational enhancement intervention postpartum alcohol use.

Design

This study is a single-blinded, randomized controlled effectiveness trial in which pregnant women were assigned to receive usual care or up to 5 face-to-face brief motivational enhancement sessions lasting 10–30 minutes each and occurring at study enrollment, 4 and 8 weeks after enrollment, 32 weeks of gestation, and 6 weeks postpartum.

Setting

The setting is in a large, urban, obstetrics clinic.

Participants

Participants were women who were ≥ 18 years old, < 20 weeks of gestation, and consumed alcohol during pregnancy. Of 3438 women screened, 330 eligible women were assigned to usual care (n = 165) or intervention (n = 165). Due to missing data, we analyzed 125 in the intervention group and 126 in the usual care group.

Measurements

The measurements were the proportion of women with any alcohol use and the number of drinks per day, reported via follow-up telephone interviews at 4 and 8 weeks after enrollment, 32 weeks of gestation, and 6 weeks, 6 months, and 12 months postpartum.

Findings

In random effects models adjusted for confounders, the intervention group was less likely to use any alcohol (odds ratio 0.50; 95% confidence interval [CI], 0.23–1.09; P = 0.08) and consumed fewer drinks per day (coefficient − 0.11; 95% CI − 0.23–0.01; P = 0.07) than, the usual care group in the postpartum period but these differences were non-significant. Missing data during the prenatal period prevented us from modeling prenatal alcohol use.

Conclusions

Brief motivational enhancement intervention delivered in an obstetrical outpatient setting did not conclusively decrease alcohol use during the postpartum period.     

Conduct problem trajectories and alcohol use and misuse in mid to late adolescence

Background

We consider the strength of the relationship between types of conduct problems in early life and pattern of alcohol use during adolescence.

Methods

Children from the Avon Longitudinal Study of Parents and Children, a UK birth-cohort, had their level of conduct problems assessed repeatedly from 4 to 13 years using the maternal report Strengths and Difficulties Questionnaire. Developmental trajectories derived from these data were subsequently related to (i) patterns of alcohol use from 13 to 15 years, and (ii) hazardous alcohol used at age 16.

Results

Boys with ‘Adolescent Onset’ or ‘Early Onset Persistent’ conduct problems were much more likely to be high frequency drinkers between 13 and 15 years (OR 5.00 95% CI = [2.4, 10.6] and 3.9 95% CI = [2.1, 7.3] respectively) compared with those with Low or ‘Childhood Limited’ conduct. Adolescent Onset/Early Onset Persistent girls also had greater odds of this high-alcohol frequency drinking pattern (2.67 [1.4, 5.0] and 2.14 [1.2, 4.0] respectively). Associations were more moderate for risk of hazardous alcohol use at age 16. Compared to 32% among those with low conduct problems, over 40% of young people classified as showing Adolescent Onset/Early Onset Persistent conduct problems were drinking hazardously (OR 1.52 [1.09, 2.11] and 1.63 [1.22, 2.18] respectively).

Conclusions

Whilst persistent conduct problems greatly increase the risk of adolescent alcohol problems, the majority of adolescents reporting hazardous use at age 16 lack such a history. It is important, therefore, to undertake alcohol prevention among all young people as a priority, as well as target people with manifest conduct problems.     

Initial insight into why physical activity may help prevent adolescent smoking uptake

Introduction

Whereas research supports the importance of regular physical activity to decrease the likelihood of smoking uptake, the mechanisms accounting for this relationship are poorly understood. We sought to determine whether the enjoyment or reward derived from physical activity is one mechanism underlying the relationship between smoking and physical activity.

Methods

The sample was composed of 1374 adolescents participating in a prospective longitudinal survey study of health behaviors. Variables were measured via self-report every six months for eight waves of data spanning four years.

Results

An associative processes latent growth curve model revealed a significant and negative indirect effect of baseline physical activity on baseline smoking through baseline physical activity reward (b_indirect = −.18, z = −3.11, p = .002; 95% CI = −.29, −.07). Similarly, there was a significant and negative indirect effect of physical activity trend on smoking trend through physical activity reward trend (b_indirect = −.16, z = −2.09, p = .04; 95% CI = −.30, −.01). The effect of physical activity on smoking at baseline and across time was completely mediated by physical activity reward. There was less support for the idea that smoking progression was associated with reduced physical activity reward and subsequent declines in physical activity.

Conclusions

This study provides the first evidence implicating physical activity reward as one mechanism by which physical activity reduces the likelihood of adolescent smoking uptake. Smoking prevention interventions that promote physical activity and target physical activity enjoyment may have an important impact on adolescent smoking initiation and progression.