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Aims Many observational studies suggest that increased drinking frequency is associated with reduced mortality among those with low-dose alcohol consumption. The purpose of this paper was to examine whether frequent drinkers consume lower-risk amounts during drinking days or have favorable risk factor profiles compared with those who drink less frequently, and discuss implications for the larger debate about the limitations of non-randomized studies about 'moderate' drinking and the development of low-risk drinking guidelines. Methods Data from the 2008 Behavioral Risk Factor Surveillance System survey were used to characterize alcohol consumption characteristics and their relationship with risk factors among adult drinking men who consumed an average of fewer than two drinks per day and adult drinking adult women who consumed an average of less than one drink per day. Results Those who drank relatively infrequently (14 or fewer days per month) consumed more during drinking days, were more likely to exceed the US Dietary Guidelines drinking limits (41.0% versus 9.7%) and had a larger proportion of drinking days that included binge drinking (13.4% versus 4.3%). Infrequent drinkers also had a higher prevalence of 13 of 15 risk factors assessed. Findings from analyses of those aged ≥40 years were similar. Conclusions Among those with low average alcohol consumption, infrequent drinkers drink more during drinking days and have unfavorable risk factors profiles compared with more frequent drinkers, suggesting that confounding may contribute to favorable associations with 'moderate' average alcohol consumption and increased drinking frequency observed in non-randomized studies. [ABSTRACT FROM AUTHOR]

Aims Nicotine dependence is a highly heritable disorder associated with severe medical morbidity and mortality. Recent meta-analyses have found novel genetic loci associated with cigarettes per day ( CPD), a proxy for nicotine dependence. The aim of this paper is to evaluate the importance of phenotype definition (i.e. CPD versus Fagerström Test for Cigarette Dependence ( FTCD) score as a measure of nicotine dependence) on genome-wide association studies of nicotine dependence. Design Genome-wide association study. Setting Community sample. Participants A total of 3365 subjects who had smoked at least one cigarette were selected from the Study of Addiction: Genetics and Environment ( SAGE). Of the participants, 2267 were European Americans, 999 were African Americans. Measurements Nicotine dependence defined by FTCD score ≥4, CPD. Findings The genetic locus most strongly associated with nicotine dependence was rs1451240 on chromosome 8 in the region of CHRNB3 [odds ratio ( OR) = 0.65, P = 2.4 × 10−8]. This association was further strengthened in a meta-analysis with a previously published data set (combined P = 6.7 × 10−16, total n = 4200). When CPD was used as an alternate phenotype, the association no longer reached genome-wide significance ( β = −0.08, P = 0.0004). Conclusions Daily cigarette consumption and the Fagerstrom Test for Cigarette Dependence show different associations with polymorphisms in genetic loci. [ABSTRACT FROM AUTHOR]

Aims To test whether exposure to party-related alcohol advertising is associated with drinking behavior in a national US sample of adolescents and young adults, independently of exposure to other alcohol advertising. Design Longitudinal telephone- and web-based surveys conducted in 2011 and 2013. Setting All regions of the United States, participants selected via mixed-mode random-digit-dial landline and cellphone frames. Participants A sample of 705 respondents who never had a whole drink of alcohol at baseline (mean age 16.9 years, 53.3% female) and a sample of 1036 who never had six or more drinks during one drinking occasion (mean age 17.4 years, 55.8% female). Measurements Outcome measures were onset of alcohol use and binge drinking during the study interval. Primary predictor was exposure to television alcohol advertising, operationalized as contact frequency and brand recall for 20 randomly selected alcohol advertisements. Independent post-hoc analyses classified all advertisements as 'party' or 'non-party' advertisements. Socio-demographics, sensation-seeking, alcohol expectancies and alcohol use of friends and family were assessed as covariates. Findings Onset rates for having the first whole drink of alcohol and for first binge drinking were 49.2% and 29.5%, respectively. On average, approximately half (median = 10.2) of the 20 alcohol advertisements in each individual survey were 'party' advertisements. If both types of exposures ('party' and 'non-party') were included in the regression model, only 'party' exposure remained a significant predictor of alcohol use onset [adjusted odds ratio (AOR) = 19.17; 95% confidence interval (CI) = 3.72-98.79] and binge drinking onset (AOR = 3.87; 95% CI = 1.07-13.99) after covariate control. Conclusions Adolescents and young adults in the United States appear to have higher rates of alcohol use and binge drinking onset if they have higher exposure to alcohol advertisements using a partying theme, independently of the amount of exposure to alcohol advertisements with non-party themes. [ABSTRACT FROM AUTHOR]

Aims To compare three missing data strategies: (i) the latent growth model that assumes the data are missing at random ( MAR) model; (ii) the Diggle- Kenward missing not at random ( MNAR) model, where dropout is a function of previous/concurrent urinalysis ( UA) submissions; and (iii) the Wu- Carroll MNAR model where dropout is a function of the growth factors. Design Secondary data analysis of a National Drug Abuse Treatment Clinical Trials Network trial that examined a 7-day versus 28-day taper (i.e. stepwise decrease in buprenorphine/naloxone) on the likelihood of submitting an opioid-positive UA during treatment. Setting 11 out-patient treatment settings in 10 US cities. Participants A total of 516 opioid-dependent participants. Measurements Opioid UAs provided across the 4-week treatment period. Findings The MAR model showed a significant effect ( B = −0.45, P < 0.05) of trial arm on the opioid-positive UA slope (i.e. 28-day taper participants were less likely to submit a positive UA over time) with a small effect size ( d = 0.20). The MNAR Diggle- Kenward model demonstrated a significant ( B = −0.64, P < 0.01) effect of trial arm on the slope with a large effect size ( d = 0.82). The MNAR Wu- Carroll model showed a significant ( B = −0.41, P < 0.05) effect of trial arm on the UA slope that was relatively small ( d = 0.31). Conclusions This performance comparison of three missing data strategies (latent growth model, Diggle- Kenward selection model, Wu- Carrol selection model) on sample data indicates a need for increased use of sensitivity analyses in clinical trial research. Given the potential sensitivity of the trial arm effect to missing data assumptions, it is critical for researchers to consider whether the assumptions associated with each model are defensible. [ABSTRACT FROM AUTHOR]

Aims To investigate the prevalence of awareness of the online illicit drug marketplace Silk Road ( SR), consumption of drugs purchased from SR and reasons for use and non-use of SR. Design and setting Global Drug Survey: purposive sample collected in late 2012. Participants The base sample ( n = 9470) reported recent drug purchase and resided in the United Kingdom ( n = 4315, median age 24, 76% male), Australia ( n = 2761, median age 32, 76% male) or the United States ( n = 2394, median age 21, 80% male). Measurements Online questionnaire. Findings A total of 65% of US, 53% of Australian and 40% of UK respondents had heard of SR; 18% of US, 10% of UK and 7% of Australian respondents had consumed drugs purchased through SR. Across the three countries, 3,4-methylenedioxy-N-methylamphetamine (MDMA) was the most commonly purchased drug (53-60%), followed by cannabis (34-51%), lysergic acid diethylamide (LSD) (29-45%) and the 2C family (16%-27%). The most common reasons for purchasing from SR were wider range (75-89%), better quality (72-77%), greater convenience (67-69%) and the use of vendor rating systems (60-65%). The most common reasons for avoiding SR purchase were adequate drug access (63-68%) and fear of being caught (41-53%). Logistic regressions found that, compared with people from the UK, Australians [odds ratio ( OR) = 3.37; 95% confidence interval ( CI) = 2.29, 4.97) and Americans (OR = 1.46; 95% CI = 1.10, 1.94) were more likely to use SR due to lower prices; and to avoid SR purchase due to fear of being caught ( Australia: OR = 1.65; 95% CI = 1.39, 1.96; USA: OR = 1.62; 95% CI = 1.37, 1.92). Conclusions While reasons for Silk Road use accord with broader online commerce trends (range, quality, convenience, ratings), its appeal to drug purchasers is moderated by country-specific deterrents and market characteristics. [ABSTRACT FROM AUTHOR]

Aims To examine differences between early-onset versus later-onset pathological gamblers in socio-demographic characteristics, rates of Axis I and II disorders, preferred type of gambling and rates of treatment-seeking in a large nationally representative survey of adults in the United States. Design Data were collected from face-to-face interviews using the Alcohol Use Disorder and Associated Disabilities Interview Schedule DSM- IV version IV ( AUDADIS- IV). Setting and Measurement The study drew on data from the United States' National Epidemiologic Survey on Alcohol and Related Conditions ( NESARC). Participants All individuals with a DSM- IV diagnosis of pathological gambling ( PG). To be consistent with prior studies, age of onset of PG was dichotomized as 25 years and younger (early-onset) versus 26 years and older (later-onset). Findings Individuals with early-onset PG were more likely than individuals with later-onset PG to be male [odds ratio ( OR) = 2.86; 95% confidence interval ( CI) = 1.20, 6.82], never married ( OR = 3.51; 95% CI = 1.39, 8.84), to have income below US$70 000 ( OR = 0.09; 95% CI = 0.01, 0.61), to belong to younger cohorts ( OR = 0.93; 95% CI = 0.89, 0.97) and to have a cluster B personality disorder ( OR = 4.11; 95% CI = 1.77, 9.55), but less likely to have a mood disorder ( OR = 0.42; 95% CI = 0.19, 0.94). There were no differences between individuals with early- and later-onset PG regarding rates of treatment-seeking ( OR = 0.71; 95% CI = 0.20, 2.43) or preferred type of gambling ( OR = 2.00; 95% CI = 0.55, 7.3). All results remained significant after adjusting for age, sex and race, except the difference in the prevalence for mood disorders, which was no longer significant. Conclusions Individuals with early-onset versus later-onset pathological gambling differ in several socio-demographic and clinical characteristics, but not in their preferred types of game. Individuals from more recent cohorts appear to be at significantly increased risk for developing early-onset pathological gambling. [ABSTRACT FROM AUTHOR]

Aims To determine comorbidity patterns in treatment-seeking substance use disorder ( SUD) patients with and without adult attention deficit hyperactivity disorder ( ADHD), with an emphasis on subgroups defined by ADHD subtype, taking into account differences related to gender and primary substance of abuse. Design Data were obtained from the cross-sectional International ADHD in Substance use disorder Prevalence ( IASP) study. Setting Forty-seven centres of SUD treatment in 10 countries. Participants A total of 1205 treatment-seeking SUD patients. Measurements Structured diagnostic assessments were used for all disorders: presence of ADHD was assessed with the Conners' Adult ADHD Diagnostic Interview for DSM-IV ( CAADID), the presence of antisocial personality disorder ( ASPD), major depression ( MD) and (hypo)manic episode ( HME) was assessed with the Mini International Neuropsychiatric Interview- Plus ( MINI Plus), and the presence of borderline personality disorder ( BPD) was assessed with the Structured Clinical Interview for DSM-IV Axis II ( SCID II). Findings The prevalence of DSM-IV adult ADHD in this SUD sample was 13.9%. ASPD [odds ratio ( OR) = 2.8, 95% confidence interval ( CI) = 1.8-4.2], BPD ( OR = 7.0, 95% CI = 3.1-15.6 for alcohol; OR = 3.4, 95% CI = 1.8-6.4 for drugs), MD in patients with alcohol as primary substance of abuse ( OR = 4.1, 95% CI = 2.1-7.8) and HME ( OR = 4.3, 95% CI = 2.1-8.7) were all more prevalent in ADHD+ compared with ADHD− patients ( P < 0.001). These results also indicate increased levels of BPD and MD for alcohol compared with drugs as primary substance of abuse. Comorbidity patterns differed between ADHD subtypes with increased MD in the inattentive and combined subtype ( P < 0.01), increased HME and ASPD in the hyperactive/impulsive ( P < 0.01) and combined subtypes ( P < 0.001) and increased BPD in all subtypes ( P < 0.001) compared with SUD patients without ADHD. Seventy-five per cent of ADHD patients had at least one additional comorbid disorder compared with 37% of SUD patients without ADHD. Conclusions Treatment-seeking substance use disorder patients with attention deficit hyperactivity disorder are at a very high risk for additional externalizing disorders. [ABSTRACT FROM AUTHOR]

Aims To examine non-medical use of prescription opioids ( NMUPO) patterns during the transition from adolescence to adulthood, and assess individual characteristics and other substance use behaviors associated with longitudinal patterns of NMUPO. Design Nationally representative samples of high school seniors in the United States (wave 1: modal age 18 years) were followed longitudinally across three biennial follow-up waves (waves 2, 3 and 4: modal ages 19/20, 21/22 and 23/24 years). Setting Data were collected via self-administered questionnaires to high school seniors and young adults. Participants The longitudinal sample consisted of 27 268 individuals in 30 cohorts (high school senior years 1976-2005) who participated in all four waves. Measurements Self-reports of NMUPO and other substance use behaviors. Findings Approximately 11.6% [95% confidence interval ( CI) = 11.2%, 12.0%] of the sample reported past-year NMUPO in at least one of the four waves. Among those who reported past-year NMUPO in at least one wave, 69.0% (67.6%, 70.4%), 20.5% (19.3%, 21.7%), 7.8% (7.1%, 8.6%) and 2.7% (2.3%, 3.1%) reported NMUPO at one, two, three and four waves, respectively. Several wave 1 variables were associated with greater odds of multiple waves of NMUPO and individuals who reported more waves of NMUPO had greater odds of other substance use behaviors. Conclusions Although most non-medical use of prescription opioids among 18-year-olds in the United States appears to be non-continuing, approximately one-third of the sample reporting non-medical use of prescription opioids appear to continue use beyond age 18 and have elevated odds of other substance use behaviors at ages 23/24. [ABSTRACT FROM AUTHOR]

Aims We determined whether or not homelessness is associated with cigarette smoking independent of other socio-economic measures and behavioral health factors, and whether homeless smokers differ from non-homeless smokers in their desire to quit. Design, setting and participants We analyzed data from 2678 adult respondents to the 2009 Health Center Patient Survey, a nationally representative cross-sectional survey of homeless and non-homeless individuals using US federally funded community health centers. Measurements We used multivariable logistic regression to examine the association between homelessness and (i) current cigarette smoking among all adults, and (ii) past-year desire to quit among current smokers, adjusting for demographic, socio-economic and behavioral health characteristics. Findings Adults with any history of homelessness were more likely than never homeless respondents to be current smokers (57 versus 27%, P < 0.001). In multivariable models, a history of homelessness was associated independently with current smoking [adjusted odds ratio ( AOR) 2.09; 95% confidence interval ( CI) = 1.49-2.93], even after adjusting for age, sex, race, veteran status, insurance, education, employment, income, mental illness and alcohol and drug abuse. Housing status was not associated significantly with past-year desire to stop smoking in unadjusted ( P = 0.26) or adjusted ( P = 0.60) analyses; 84% of currently homeless, 89% of formerly homeless and 82% of never homeless smokers reported wanting to quit. Conclusions Among patients of US health centers, a history of homelessness doubles the odds of being a current smoker independent of other socio-economic factors and behavioral health conditions. However, homeless smokers do not differ from non-homeless smokers in their desire to quit and should be offered effective interventions. [ABSTRACT FROM AUTHOR]

Aims To test whether psychological factors predict male smokeless tobacco ( SLT) initiation and cessation longitudinally. Design Sixteen-year longitudinal design with 95% retention at year 6 and 82% at year 16. Setting Forty Washington State school districts. Participants SLT use data were gathered on a cohort of adolescents (91% Caucasian). For SLT initiation, the sample size was 2468. For SLT cessation, sample sizes were 219 (age 20 outcome) and 192 (age 28 outcome). Measurements Self-reported psychological measures of parental disobedience ('parent non-compliance'), peer influence ('friend compliance'), rebelliousness and thrill-seeking were taken at ages 12 and 18. SLT use was measured at ages 12, 18, 20 and 28 years. Findings For SLT initiation, scoring highly on the following psychological factors at age 12 at least doubled the odds of daily SLT use at age 18 ( P < 0.001): friend compliance [odds ratio ( OR): 2.56, 95% confidence interval ( CI): 1.78-3.68), rebelliousness ( OR: 2.16, 95% CI: 1.46-3.19) and thrill-seeking ( OR: 2.33, 95% CI: 1.45-3.75). For SLT cessation, none of the psychological factors at age 18 predicted SLT cessation at age 20 or 28 ( P value range: 0.06-0.84). Conclusion Peer influence, rebelliousness, and thrill-seeking appear to predict smokeless tobacco initiation strongly among male youth in the United States. [ABSTRACT FROM AUTHOR]

Aims To assess age variation in correlates of drinking cessation. Design Prospective study of a US general population sample. Setting Face-to-face household interviews. Participants Past-year ≥ monthly drinkers interviewed at baseline and 3-year follow-up ( n = 14 885). Measurements Baseline values and selected changes over follow-up in alcohol consumption, alcohol use disorder ( AUD), socio-demographic and health characteristics, other substance use and psychiatric comorbidity were used to predict drinking cessation in three age groups. Findings Correlates of drinking cessation varied over the life-course, with pregnancy/presence of an infant, nicotine or drug use disorder, incident AUD, cluster A personality disorder, liver disease and incident retirement being important at younger ages and high-school graduation, family income ≥ $70 000, volume of ethanol intake, Asian race/ethnicity, mood disorder and incident cardiovascular disease being significant at older ages. Age-invariant correlates included smoking cessation over follow-up, odds ratio ( OR) = 2.82 [95% confidence interval ( CI): 1.62-4.92] to 3.45 (2.20-5.39); college education, OR = 0.42 (0.27-0.65) to 0.54 (0.36-0.83); black and Hispanic race/ethnicity, OR = 1.74 (1.18-2.29) to 1.88 (1.21-2.93) and 1.58 (1.11-1.25) to 1.73 (0.83-3.63), respectively, and months since last drink, OR = 1.24 (1.13-1.36) to 1.29 (1.19-1.39). Conclusions Factors associated with ceasing alcohol use in US adults appear to differ over the life-course, reflecting age variation in both their prevalence and impact and supporting the importance of role transitions and health problems (the 'sick quitter' effect). The most consistent correlates of drinking cessation included factors reflecting ability/inability to give up potentially addictive substances and factors associated with perceived acceptability of drinking and subgroup-specific drinking contexts that might facilitate/impede continued drinking. [ABSTRACT FROM AUTHOR]

Aims To investigate the relationships between tobacco dependence, biomarkers of nicotine and carcinogen exposure and biomarkers of nicotine and carcinogen exposure per cigarette in back and white smokers. Design, setting and participants A total of 204 healthy black ( n = 69) and white ( n = 135) smokers were enrolled into two clinical studies. Measurement Nicotine equivalents (nicotine and its metabolites), 4-(methylnitrosamino)-1-(3)pyridyl-1-butanol ( NNAL) and polycyclic aromatic hydrocarbon ( PAH) metabolites were measured in urine. The Fagerström Test for Nicotine Dependence ( FTND) and time to first cigarette ( TFC) measured tobacco dependence. Findings Average TFC and FTND for blacks and whites were not significantly different. Urine NNAL and nicotine equivalents increased with increasing FTND in whites but did not increase in blacks (race × FTND interaction, both P < 0.031). The interaction term was not significant for PAHs. An inverse relationship was seen between FTND and nicotine equivalents, NNAL and PAH metabolites per cigarette in blacks but remained flat in whites (race × FTND interaction, all P ≤ 0.039). Regardless of dependence (low dependence, TFC >15 minutes; high dependence, TFC ≤15 minutes), FTND and TFC were not correlated significantly with urine nicotine equivalents and carcinogen exposure in blacks. We found moderate correlations between FTND and TFC and nicotine equivalents and carcinogen exposure among whites of low dependence and non-significant correlations among whites of high dependence. Conclusion In the United States, tobacco dependence measures were related linearly to nicotine intake and carcinogen exposure in white but not in black smokers. The relationship between dependence measures and tobacco biomarkers in black smokers regardless of level of dependence resembled highly dependent white smokers. [ABSTRACT FROM AUTHOR]

ABSTRACT Aims Marital dissolution is associated with increased risk of problematic drinking. However, marriage to a problem drinker also increases this risk, and ending this type of relationship may actually decrease risk of problematic drinking. This study tested whether women ending their marriage to a problem drinker exhibited improvements in drinking. Design National Epidemiologic Survey on Alcohol and Related Conditions, a two-wave nationally representative survey of the US adult population. Setting In-person interviews conducted in US households. Participants Females married or living as if married at wave 1 at least 18 years of age. Measurements Socio-demographics, drinking frequency, drinking quantity, alcohol use disorders, problem drinking, partner problem drinking and relationship dissolution. Findings Ending marriage to a non-problem drinker predicted increased frequency of drinking [risk ratio (RR) = 1.55; 95% confidence interval (CI) = 1.43, 1.67], heavier drinking (RR = 1.30; 95% CI = 1.71, 1.45), more problematic drinking (RR = 2.45; 95% CI = 2.17, 2.77) and a greater likelihood of use disorder diagnosis [odds ratio (OR) = 2.2; 95% CI = 1.67, 2.91]. Ending a relationship with a problem drinker predicted less frequent drinking (RR = 0.94; 95% CI = 0.90, 0.98), less heavy drinking (RR = 0.84; 95% CI = 0.78, 0.90) and fewer alcohol-related problems (RR = 0.77; 95% CI = 0.62, 0.95). Conclusions Ending a marriage with a husband who drinks problematically may decrease risk of alcohol-related problems among women, substantiating the need for alcohol treatments to address a problem drinking partner. [ABSTRACT FROM AUTHOR]

ABSTRACT Aims The US Food and Drug Administration must consider whether to ban the use of menthol in cigarettes. This study examines how current smokers might respond to such a ban on menthol cigarettes. Design Convenience sample of adolescent and adult smokers recruited from an online survey panel. Setting United States, 2010. Participants A total of 471 adolescent and adult current cigarette smokers. Measurements Respondents were asked a series of questions about how they might react if menthol cigarettes were banned. In addition, participants completed a simulation purchase task to estimate the demand for menthol and non-menthol cigarettes across a range of prices. Findings Overall, 36.1% of respondents said they always (18.9%) or usually (17.2%) smoked menthol cigarettes. When asked how they might respond to a ban on menthol cigarettes, 35% of current menthol smokers said they would stop smoking, and 25% said they would 'find a way to buy a menthol brand'. Those who reported they might quit tended to have greater current intentions to quit [odds ratio (OR) = 4.47], while those who reported that they might seek illicit menthol cigarettes were far less likely to report current intentions to quit (OR = 0.06). Estimates for demand elasticity for preferred cigarette type were similar for menthol (α = 0.0051) and non-menthol (α = 0.0049) smokers. Demand elasticity and peak consumption were related to usual cigarette type and cigarettes smoked per day, but did not appear to differ by race, gender or age. Conclusions Preliminary evidence suggests that a significant minority of smokers of menthol cigarettes in the United States would try to stop smoking altogether if such cigarettes were banned. [ABSTRACT FROM AUTHOR]

ABSTRACT Aims To characterize smokeless tobacco initiation and persistence in relation to deployment, combat, occupation, smoking and mental health symptoms. Design Prospective cohort, utilizing self-reported survey data from the Millennium Cohort Study. Setting US military service members in all branches including active duty, reserve and National Guard. Participants Population-based sample of 45 272 participants completing both baseline (July 2001-June 2003; n = 77 047) and follow-up (June 2004-January 2006; n = 55 021) questionnaires (follow-up response rate = 71.4%). Measurements Self-reported smokeless tobacco initiation and persistence. Findings Over the study period, 72.4% did not deploy, 13.7% deployed without combat exposures and 13.9% deployed with combat exposures, while 1.9% were smokeless tobacco initiators and 8.9% were persistent users. The odds of initiation were greater for deployers with combat exposure [odds ratio (OR), 1.76; 95% confidence interval (CI), 1.49-2.09], deployers without combat exposure (OR, 1.31; 95% CI, 1.07-1.60) and those who deployed multiple times (OR, 1.67; 95% CI, 1.31-2.14), as well as in smoking recidivists/initiators (OR, 4.65; 95% CI, 3.82-5.66) and those reporting post-traumatic stress disorder symptoms (OR, 1.54; CI, 1.15-2.07). A similar pattern for higher odds of persistent use was observed for deployment and combat exposure, but not for smoking and mental health symptoms. Military occupation was not significantly associated with initiation or persistence. Conclusions Deployment and combat exposure in the US military are associated with increased risk of smokeless tobacco initiation and persistence while smoking and symptoms of post-traumatic stress disorder increase the odds for initiation. Research is needed on aspects of military service amenable to the reduction or prevention of tobacco consumption. [ABSTRACT FROM AUTHOR]

ABSTRACT Aims This study aimed to examine the associations between reported exposure to anti-smoking warnings at the point-of-sale (POS) and smokers' interest in quitting and their subsequent quit attempts by comparing reactions in Australia where warnings are prominent to smokers in other countries. Design A prospective multi-country cohort design was employed. Setting Australia, Canada, the United Kingdom and the United States. Participants A total of 21 613 adult smokers who completed at least one of the seven waves (2002-08) of the International Tobacco Control Four Country Survey were included in the analysis. Measurements Reported exposure to POS anti-smoking warnings and smokers' interest in quitting at the same wave and quit attempts over the following year. Findings Compared to smokers in Canada, the United Kingdom and the United States, Australian smokers reported higher levels of awareness of POS anti-smoking warnings, and this difference was consistent over the study period. Over waves in Australia (but not in the other three countries) there was a significantly positive association between reported exposure to POS anti-smoking warnings and interest in quitting [adjusted odds ratio = 1.139, 95% confidence interval (CI) 1.039-1.249, P < 0.01] and prospective quit attempts (adjusted odds ratio = 1.216, 95% CI 1.114-1.327, P < 0.001) when controlling for demographics, smoking characteristics, overall salience of anti-smoking information and awareness of anti-smoking material from channels other than POS. Conclusions Point-of-sale health warnings about tobacco are more prominent in Australia than the United Kingdom, the United States or Canada and appear to act as a prompt to quitting. [ABSTRACT FROM AUTHOR]

ABSTRACT Aims Studies of the relationship between social norms and marijuana use have generally focused on individual attitudes, leaving the influence of larger societal-level attitudes unknown. The present study investigated societal-level disapproval of marijuana use defined by birth cohort or by time-period. Design Combined analysis of nationally representative annual surveys of secondary school students in the United States conducted from 1976 to 2007 as part of the Monitoring the Future study. Setting In-school surveys completed by adolescents in the United States. Participants A total of 986 003 adolescents in grades 8, 10 and 12. Measurements Main predictors included the percentage of students who disapproved of marijuana in each birth cohort and time-period. Multi-level models with individuals clustered in time-periods of observation and birth cohorts were modeled, with past-year marijuana use as the outcome. Findings Results indicated a significant and strong effect of birth cohort disapproval of marijuana use in predicting individual risk of marijuana use, after controlling for individual-level disapproval, perceived norms towards marijuana and other characteristics. Compared to birth cohorts in which most (87-90.9%) adolescents disapproved of marijuana use, odds of marijuana use were 3.53 times higher in cohorts where fewer than half (42-46.9%) disapproved (99% confidence interval: 2.75, 4.53). Conclusions Individuals in birth cohorts that are more disapproving of marijuana use are less likely to use, independent of their personal attitudes towards marijuana use. Social norms and attitudes regarding marijuana use cluster in birth cohorts, and this clustering has a direct effect on marijuana use even after controlling for individual attitudes and perceptions of norms. [ABSTRACT FROM AUTHOR]