Patterns of adolescent smoking and later nicotine dependence in young adults: a 10-year prospective study

Have there been changes in daily smoking and cigarette consumption among adolescents? Investigation between 1999 and 2019 among Finnish adolescents

BACKGROUND AND AIMS

It is postulated that due to decreased smoking rates and increased denormalisation of smoking, those who start and maintain smoking have more socially disadvantaged characteristics and are more dependent on nicotine than those who do not (the so-called 'hardening' hypothesis). The aim of this study was to measure changes in daily smoking and cigarette consumption among Finnish adolescents according to background factors.

DESIGN AND SETTING

A repeated cross-sectional study using data from European School Survey Project on Alcohol and other Drugs (ESPAD) on six representative cross-sections of 15- to 16-year-old students between 1999 and 2019 in Finland.

PARTICIPANTS

A total of 11 377 males and 12 247 females.

MEASUREMENTS

The outcome measures included the proportion of daily smokers among current smokers, daily smoking and the estimated mean number of smoked cigarettes per day (CPD). Substance use, parental monitoring and school performance were used as independent variables. All measures were self-reported.

FINDINGS

Daily smoking decreased over time and daily smokers constituted a smaller part of current smokers in 2019 compared with 1999 (the ratio among boys 0.68 and 0.43, respectively; among girls 0.59 and 0.43). Boys using cannabis (interaction between cannabis*survey year: P = 0.020; in 2019 odds ratio [OR]: 3.68, 95% confidence interval [CI] 2.23-6.08) and girls with heavy episodic drinking (interaction between heavy episodic drinking*survey year: P = 0.006, in 2019 OR: 9.00, 95% CI 5.61-14.42) had elevated adjusted odds for daily smoking over time. The estimated mean number of CPD decreased among daily smokers from 9.0 in 1999 to 7.2 in 2019 (P = 0.0002) and the differences diminished between groups based on gender, snus/alcohol use and parental monitoring. The between-group differences remained with regard to cannabis use (P = 0.0233 in 2019) and school performance (P = 0.0111 in 2019).

CONCLUSIONS

Among currently smoking Finnish adolescents, the proportion of daily smokers decreased between 1999 and 2019, as did the number of cigarettes smoked per day (CPD) among daily smokers, suggesting an absence of 'hardening' in this group. However, differences were observed related to the odds of daily smoking and the mean number of CPD, indicating the change has been less favorable among some adolescent groups than others.

E-cigarette use and conventional cigarette smoking among European students: findings from the 2019 ESPAD survey

BACKGROUND AND AIMS

Representative data on e-cigarette use among European adolescents are scant. This study reports current vaping and tobacco smoking individual and country-specific correlates among European students.

DESIGN

Cross-sectional survey: 2019 European School Survey Project on Alcohol and Other Drugs (ESPAD) collecting data on risk behaviours on a representative sample of 16-year-old students.

SETTING

A total of 35 European countries, 25-30 with Tobacco Control Scale (TCS) and TCS components PARTICIPANTS: A total of 99 648 students (49.1% males) turning 16 years in the survey year.

MEASUREMENTS

Data on current cigarette and e-cigarette use were gathered through a self-administered questionnaire which also collected socio-demographics and individual and family characteristics. ESPAD data were integrated with country-level data on TCS and selected TCS parameters to assess their association with the prevalence of current cigarette and e-cigarette use.

FINDINGS

Of the 99 648 participating students, 12.4% were current e-cigarette users, from 5.5% in Serbia to 41.4% in Monaco; 19.3% current smokers, from 5.1% in Iceland to 32.4% in Italy. Compared with non-users, current e-cigarette users less frequently came from an average well-off family [odds ratio (OR) = 0.85, 95% confidence interval (CI) = 0.80-0.90] and lived in countries with higher cigarette prices (OR = 0.71, 95% CI = 0.50-0.99), restrictive measures on tobacco advertising and promotion (OR = 0.79, 95% CI = 0.63-0.99) and intermediate implementation of tobacco control measures (OR = 0.57, 95% CI = 0.38-0.85). Current vapers were more frequently life ever smokers (OR = 7.31, 95% CI = 6.47-8.25), were early smokers (OR = 4.35, 95% CI = 3.66-5.17), males (OR = 1.61, 95% CI = 1.55-1.67), from non-traditional families (OR = 1.43, 95% CI = 1.34-1.53), with relatively low parental education (OR = 1.15, 95% CI = 1.10-1.20). Compared with non-smokers, current smokers had similar family characteristics to vapers, and were less likely to live in countries with higher cigarette prices (OR = 0.70, 95% CI = 0.49-0.99) and higher spending on public anti-tobacco media campaigns (OR = 0.23, 95% CI = 0.10-0.50).

CONCLUSIONS

E-cigarette use among European adolescents is associated with weaker tobacco control measures, particularly on tobacco price, advertising and promotion. Besides preventing tobacco smoking, the adoption of governmental tobacco control policies in European countries also seems to contribute to the prevention of vaping among adolescents.

Racial/ethnic and gender differences in smoking in early middle adulthood

Research has documented important differences in smoking rates across race/ethnicity, gender, and age. Much of the research has either focused on smoking initiation among adolescents or cessation among adults, but little is known about racial/ethnic patterns in intermittent and daily smoking across young and early middle adulthood. We therefore use the life course perspective to identify how racial/ethnic and gender differences in smoking unfold across adulthood. Analyses investigate whether racial/ethnic and gender differences exist in the likelihood of daily smoking in early middle adulthood and whether these disparities persist after the inclusion of adolescent and early midlife sociodemographic characteristics and young adult smoking patterns. Descriptive statistics and multivariate binary logistic regression analyses employ recent data from a nationally representative sample of adults using the National Longitudinal Study of Adolescent to Adult Health (Add Health; N = 8,506). We find evidence that life course patterns of smoking differ across race/ethnicity and gender subgroups. In early middle adulthood (ages 33-44), White women are more likely to smoke daily than Black or Hispanic women. In contrast, there are no significant differences between White and Black men, but White men are more likely to smoke daily than Hispanic men. These racial/ethnic differences are no longer significant for men when previous smoking is controlled, suggesting that early young adult smoking plays an important role in the development of smoking disparities across race/ethnicity. Further, we find that young adult intermittent smoking is associated with daily smoking in early midlife, and this relationship is stronger for Black, compared to White, men and women. Although Black women display lower odds of daily smoking in early midlife compared to White women, they exhibit a higher risk of transitioning from intermittent to daily smoking. These results highlight the importance of considering a greater diversity of life course patterns in smoking across race/ethnicity and gender in future research and policies.

Police Stops and Adolescent Substance Use: Findings From the United Kingdom Millennium Cohort Study

PURPOSE

The aim of this study is to investigate associations between police stops and adolescent substance use among a large, representative sample of adolescents in the United Kingdom (UK).

METHODS

Data from the three most recent sweeps of the UK Millennium Cohort Study, a nationally representative contemporary birth cohort of children born in the UK between September 2000 and January 2002, were analyzed in 2021 (N = 10,345). Lifetime police stops are assessed at age 14 (Sweep 6, 2015) and a diverse set of adolescent substance use behaviors are assessed at age 17 (Sweep 7, 2018). Weights are used to account for sample design and multiple imputation for missing data.

RESULTS

Youth experiencing police stops by the age of 14 (14.72%) reported significantly higher engagement in substance use behaviors at age 17, including frequent binge drinking (adjusted relative risk ratio [ARRR] = 3.56, confidence interval [CI] = 2.80-4.03), cigarette use (ARRR = 3.97, CI = 3.26-4.84), e-cigarette use (ARRR = 2.22, CI = 1.69-2.93), cannabis use (ARRR = 3.63, CI = 2.88-4.57), and illicit drug use (adjusted incidence rate ratio = 3.06, CI = 2.45-3.81). Ancillary analyses revealed that findings linking police stops to substance use emerge across distinct stop features (e.g., questioned vs. warned), following adjustment for substance use at age 14, and when examining substance use initiation after the age of 14.

CONCLUSIONS

Police officers should be trained to effectively communicate and interact with youth to mitigate adverse sequelae of stops. Youth may also benefit from mental health and substance use screenings as well as counseling care following these events.

Adverse childhood experiences and adolescent nicotine and marijuana vaping: Findings from a statewide sample of Florida youth

A wealth of research links exposure to adverse childhood experiences (ACEs) with negative outcomes including nicotine and marijuana use. In addition, an emerging line of research has documented associations between exposure to ACEs and vaping activity in American adults and international samples of adolescents. Very limited research, however, has explored whether a history of ACEs is linked with adolescent nicotine and marijuana vaping activity in an American sample. This study addresses this gap in the literature by employing multinomial logistic regression to examine whether cumulative exposure to ACEs is associated with adolescent nicotine vaping, dual mode use of nicotine, marijuana vaping, and dual mode use of marijuana in a sample of Florida high school students. Our findings reveal that greater cumulative exposure to ACEs (up to 5 ACEs) in adolescents leads to an increase in the likelihood of vaping nicotine and marijuana. In addition, greater cumulative exposure to ACEs (up to 6 ACEs) leads to an increase in the likelihood of using nicotine and marijuana through multiple delivery modes.

Examining potential risk factors for early age of nicotine vaping initiation in a sample of Florida youth

Previous research has examined risk factors for nicotine vaping in young adults and older adolescents. Even so, significantly less research has examined risk factors for initiating nicotine vaping in early adolescence. This paper addresses this gap in the literature by examining risk factors for initiating nicotine vaping in a sample of middle- and high-school students. In order to do so, we analyze data from the 2019 cohort of the Florida Youth Substance Abuse Survey (FYSAS). We employ multinomial logistic regression and logistic regression to examine potential risk factors for early age of nicotine vaping initiation. Our findings reveal that early age of nicotine vaping initiation is associated with cigarette use, alcohol use, having substance using peers, lifetime incidence of arrest, and lifetime incidence of school suspension. In conclusion, our findings reveal that early age of nicotine vaping initiation is associated with other forms of risky behavior in adolescence (i.e., substance use, misbehavior leading to arrest and/or school suspension). We discuss the implications of these findings for future research.

Health Risk Behaviors and Self-Esteem Among College Students: Systematic Review of Quantitative Studies

BACKGROUND

Due to their impact on premature mortality and long-term disabilities, a better understanding of health risk behavior (HRB) determinants among college students is crucial in order to build the most appropriate prevention tools. Although self-esteem appears to be a relevant candidate, a clear picture summarizing its multiple links with HRB is lacking to guide clinicians and researchers. This study aims to provide a systematic review of the associations between health risk behavior and self-esteem among college students.

METHODS

This search was performed in several databases on 02/02/17. Study eligibility criteria were original articles in peer-reviewed journals, in English; observational quantitative studies; among college students; and investigated the association between self-esteem and HRB. The PRISMA statements were complied with.

RESULTS

One hundred fifteen articles were included: 46 on substance use, 35 on sexual behavior, 11 on nutritional habits, 27 on physical activity, and 5 on other HRB. Most studies reported an association between higher self-esteem and healthier behavior. For alcohol consumption and number of sexual partners, both negative and positive associations have been reported. Directionality was investigated in a few studies suggesting potential bidirectional effects.

CONCLUSIONS

This review points out the need for consensus for the definition of self-esteem and HRB. There was high heterogeneity in (1) the measurement of self-esteem either in the concept measured (global vs. domain) or in the way to implement validated tools; and (2) the definition of HRB. Self-esteem seems to be a relevant target to intervene on HRB, especially alcohol abuse and physical activity.

TRIAL REGISTRATION

Registration number: PROSPERO (ID = CRD42017056599).

Is self-esteem associated with self-rated health among French college students? A longitudinal epidemiological study: the i-Share cohort

OBJECTIVES

The aim of the study was to estimate the association between self-esteem and subsequent self-rated health during college years, taking into account a wide range of potential confounders.

DESIGN

Prospective longitudinal study.

SETTING

The French i-Share cohort.

PARTICIPANTS

The sample consisted of 1011 college students.

PRIMARY AND SECONDARY OUTCOME MEASURES

The association between self-esteem and later self-rated health was evaluated using multivariate modelling.Data regarding self-rated health, global self-esteem and demographic, educational, social, behavioural, environmental and financial characteristics were collected through an internet-based questionnaire.

RESULTS

The 1011 participants had a median age of 21.9 years and 79% (795/1011) were females. Self-rated health was assessed a median of 8 months after the self-esteem measurement. Twenty per cent of the students declared average to very poor health (203/1011). Students with higher levels of self-esteem were more likely to declare good or very good self-rated health (adjusted OR=1.40, 95% CI 1.15 to 1.72, p value=0.001). Other factors associated with good or very good self-rated health were low body mass index, a comfortable financial situation during childhood and three personality traits (low persistence and harm avoidance and high cooperativeness).

CONCLUSIONS

This study offers novel findings on the impact of self-esteem on self-rated health among college students. Interventions targeting self-esteem should be experimented during university years in order to improve health outcomes.

A systematic review of anxiety across smoking stages in adolescents and young adults

BACKGROUND

In adolescence and young adults, inconsistence of the association between anxiety and smoking remains to be investigated and clarified. The aim of this study is investigated and clarified the association between anxiety and smoking stages in adolescence and young adults.

METHODS

The data on the causal influence of anxiety on smoking in adolescents and young adults aged 14 to 25 years old was retrieved from electronic databases.

RESULTS

Nineteen of 668 articles were subjected to a systematic review. Definitional differences with respect to smoking stages constrained homogeneity across the nineteen analyzed reports. Anxiety appears to play a more consistent risk role for nicotine dependent (ND) smokers than for non-nicotine dependent (non-ND) regular or daily smokers. Anxious non-ND smokers are at higher risk to become nicotine dependent.

CONCLUSIONS

A ununified definition of smoking stages is responsible for the production of inconsistent results. The analysis reinforced anxiety as a significant risk factor for smoking in one's lifetime. Anxious non-ND smokers are the key target for interventions aimed at preventing nicotine dependence and smoking-related health problems.

A neurobiological pathway to smoking in adolescence: TTC12-ANKK1-DRD2 variants and reward response

The TTC12-ANKK1-DRD2 gene-cluster has been implicated in adult smoking. Here, we investigated the contribution of individual genes in the TTC12-ANKK1-DRD2 cluster in smoking and their association with smoking-associated reward processing in adolescence. A meta-analysis of TTC12-ANKK1-DRD2 variants and self-reported smoking behaviours was performed in four European adolescent cohorts (N = 14,084). The minor G-allele of rs2236709, mapping TTC12, was associated with self-reported smoking (p = 5.0 × 10^-4) and higher plasma cotinine levels (p = 7.0 × 10^-5). This risk allele was linked to an increased ventral-striatal blood-oxygen level-dependent (BOLD) response during reward anticipation (n = 1,263) and with higher DRD2 gene expression in the striatum (p = 0.013), but not with TTC12 or ANKK gene expression. These data suggest a role for the TTC12-ANKK1-DRD2 gene-cluster in adolescent smoking behaviours, provide evidence for the involvement of DRD2 in the early stages of addiction and support the notion that genetically-driven inter-individual differences in dopaminergic transmission mediate reward sensitivity and risk to smoking.

Prevalence and correlates of adolescents' e-cigarette use frequency and dependence

BACKGROUND

Understanding predictors of e-cigarette use among adolescents in the context of wide availability and extreme popularity of these products is important for prevention and treatment. This study identifies correlates of e-cigarette use frequency and dependence among adolescent users.

METHODS

Adolescent e-cigarette users (N = 173) were recruited from the San Francisco Bay Area. Participants reported demographic and psychosocial characteristics, e-cigarette use behaviors, and cigarette use. Bivariate relationships between potential correlates were examined, and correlates significant at p < .10 were included in full models predicting frequency and dependence.

RESULTS

In the full models, frequent use was associated with receiving one's first e-cigarette from a family member rather than a friend (r = -0.23, p < .001) or a store ( = -0.13, p = .037), using nicotine in all e-cigarettes versus some e-cigarettes (r = -0.17, p = .007) or unknown nicotine use (r = -0.15, p = .014), using a customizable device versus a Juul (r = -0.22, p < .001), vape pen (r = -0.20, p = .002), or other/unknown device (r = -0.16, p = .009), and friends' e-cigarette use (r = 0.20, p = .002). Dependence was associated with younger age of first use (r = -0.18, p = .012), friends' use (r = 0.18, p = .01), and recent cigarette use (r = 0.17, p = .019).

CONCLUSIONS

When assessing problematic e-cigarette use among adolescents, it is important to consider social factors (e.g., friends' and family members' e-cigarette use), device type, and dual use with cigarettes.

Adolescent Sexual Minority Girls Are at Elevated Risk for Use of Multiple Substances

BACKGROUND

Sexual minority youth, especially girls, are at risk for alcohol, cigarette, and marijuana use when these substances are examined individually. However, little is known about concurrent use of these substances (i.e., three-substance use) in relation to sexual orientation.

OBJECTIVES

The present study compared profiles of past year alcohol, cigarette, and marijuana use between SMGs and heterosexual girls. In addition, because internalizing and externalizing symptoms are associated with substance use, we examined whether sexual orientation was associated with substance use profile over and above co-occurring psychopathology.

METHODS

Mixture modeling was used to identify patterns of alcohol (including binge drinking), cigarette, and marijuana use in the past year using a cross-sectional sample of urban adolescent girls (Pittsburgh Girls Study; N = 2,064; mean age = 17). Approximately 8% (n = 173) of the girls endorsed a lesbian or bisexual identity.

RESULTS

Five substance using classes were identified: low-level substance use (72%), marijuana use (5%), cigarette use (8%), alcohol use (8%), and three-substance use (7%). SMGs were at an increased risk for substance use than heterosexual girls, particularly three-substance use (OR = 6.69, p < .001), cigarette use (OR = 6.26, p < .001), and marijuana use (OR = 3.86, p < .001) classes. Substance use patterns were regressed on sexual orientation, internalizing symptoms (i.e., depression, anxiety), and externalizing symptoms (i.e., conduct problems, oppositional defiant disorder). The disparities remained robust after controlling for internalizing and externalizing symptoms.

CONCLUSIONS/IMPORTANCE

Clinicians and researchers should be aware of potential three-substance use among SMGs. Substance use interventions for SMG may benefit from targeting risk factors that cut-across several substances, particularly externalizing symptoms.

Wheel running exercise attenuates vulnerability to self-administer nicotine in rats

BACKGROUND

Preventing or postponing tobacco use initiation could greatly reduce the number of tobacco-related deaths. While evidence suggests that exercise is a promising treatment for tobacco addiction, it is not clear whether exercise could prevent initial vulnerability to tobacco use. Thus, using an animal model, we examined whether exercise attenuates vulnerability to the use and reinforcing effects of nicotine, the primary addictive chemical in tobacco.

METHODS

Initial vulnerability was assessed using an acquisition procedure wherein exercising (unlocked running wheel, n=10) and sedentary (locked or no wheel, n=12) male adolescent rats had access to nicotine infusions (0.01-mg/kg) during daily 21.5-h sessions beginning on postnatal day 30. Exercise/sedentary sessions (2-h/day) were conducted prior to each of the acquisition sessions. The effects of exercise on nicotine's reinforcing effects were further assessed in separate groups of exercising (unlocked wheel, n=7) and sedentary (no wheel, n=5) rats responding for nicotine under a progressive-ratio schedule with exercise/sedentary sessions (2-h/day) conducted before the daily progressive-ratio sessions.

RESULTS

While high rates of acquisition of nicotine self-administration were observed among both groups of sedentary controls, acquisition was robustly attenuated in the exercise group with only 20% of exercising rats meeting the acquisition criterion within the 16-day testing period as compared to 67% of the sedentary controls. Exercise also decreased progressive-ratio responding for nicotine as compared to baseline and to sedentary controls.

CONCLUSIONS

Exercise may effectively prevent the initiation of nicotine use in adolescents by reducing the reinforcing effects of nicotine.

Measuring tobacco dependence in the general population: Evaluation of the Cigarette Dependence Scale (CDS-12) and its adaptation to smokeless tobacco use (STDS-12) in two Swedish surveys

Aims: The 12-item Cigarette Dependence Scale (CDS-12) is an instrument suitable to assess tobacco dependence in non-clinical populations. The aim of this study was twofold: a) to evaluate the scale’s performance in a smoking population including non-daily smokers; b) to explore the scale’s adaptation to the assessment of dependence on smokeless tobacco. Methods: In a cross-sectional study we investigated performance and construct validity of the CDS-12 and of its adaptation to smokeless tobacco (STDS-12) in two Swedish population samples. The first sample consisted of young adults (1246 ever daily smokers and 1086 ever daily snus (the Swedish type of moist oral snuff) users between 19 and 28 years of age). The second sample included 1229 current smokers and 855 current users of snus between 16 and 84 years of age. Score distribution, internal consistency, factor structure, and associations with other indicators of tobacco dependence were analysed. Results: Both scales had a small amount of missing answers (below 2% in most items) and had acceptable internal consistency. Factor analyses suggested a one-factor model. CDS-12 score and proportions classified as dependent were significantly higher among daily smokers compared to non-daily smokers, positively correlated with the number of cigarettes, and negatively with quit attempts as well as their duration. The same pattern was seen for STDS-12, apart from correlation with quit attempts. Conclusions: Both the CDS-12 and its adaptation to smokeless tobacco, tested for the first time in this study, appear to perform well in population-based samples including young and non-daily tobacco users.

Do brief alcohol interventions reduce tobacco use among adolescents and young adults? A systematic review and meta-analysis

This meta-analysis synthesizes studies of brief interventions (BIs) that targeted alcohol consumption and reported both alcohol and tobacco outcomes. It examines whether BIs reduce alcohol and tobacco use for adolescents and young adults among interventions that (1) directly targeted tobacco and alcohol use, or (2) did not target tobacco use but measured it as a secondary outcome. Multiple databases and grey literature sources were searched (1980-2012) resulting in the identification of 18 randomized or controlled quasi-experimental studies (5949 participants). Analyses were conducted using random effects inverse-variance weighted three-level models. BIs were associated with a significant reduction in alcohol consumption relative to control groups [g = 0.11, 95 % CI (0.04, 0.17)] but not with a significant decrease in tobacco use [g = 0.07, 95 % CI (-0.01, 0.16)]. Directly addressing tobacco was not a significant moderator affecting tobacco use outcomes. Post-hoc exploratory analysis revealed potential questions to address with future research.

Gambling behaviors and attitudes in adolescent high-school students: Relationships with problem-gambling severity and smoking status

BACKGROUND AND AIMS

Smoking is associated with more severe/extensive gambling in adults. The purpose of this study was to examine relationships between smoking and gambling in adolescents.

METHODS

Analyses utilized survey data from 1591 Connecticut high-school students. Adolescents were classified by gambling (Low-Risk Gambling [LRG], At Risk/Problem Gambling [ARPG]) and smoking (current smoker, non-smoker). The main effects of smoking and the smoking-by-gambling interactions were examined for gambling behaviors (e.g., type, location), and gambling attitudes. Data were analyzed using chi-square and logistic regression; the latter controlled for gender, race/ethnicity, grade, and family structure.

RESULTS

For APRG adolescents, smoking was associated with greater online, school, and casino gambling; gambling due to anxiety and pressure; greater time spent gambling; early gambling onset; perceived parental approval of gambling; and decreased importance of measures to prevent teen gambling. For LRG adolescents, smoking was associated with non-strategic gambling (e.g., lottery gambling); school gambling; gambling in response to anxiety; gambling for financial reasons; greater time spent gambling; and decreased importance of measures to prevent teen gambling. Stronger relationships were found between smoking and casino gambling, gambling due to pressure, earlier onset of gambling, and parental perceptions of gambling for ARPG versus LRG adolescents.

DISCUSSION

Smoking is associated with more extensive gambling for both low- and high-risk adolescent gamblers.

CONCLUSION

Smoking may be a marker of more severe gambling behaviors in adolescents and important to consider in gambling prevention and intervention efforts with youth.

Cigarette smoking, problem-gambling severity, and health behaviors in high-school students

Introduction

Smoking and gambling are two significant public health concerns. Little is known about the association of smoking and gambling in adolescents. The current study of high-school adolescents examined: (1) smoking behavior by problem-gambling severity and (2) health-related variables by problem-gambling severity and smoking status.

Methods

Analyses utilized survey data from 1591 Connecticut high-school students. Adolescents were classified by problem-gambling severity (Low-Risk Gambling [LRG], At-Risk/Problem Gambling [ARPG]) and smoking status (current smoker, non-smoker). Analyses examined the smoking behavior of ARPG versus LRG adolescents as well as the smoking-by-problem-gambling-severity interactions for health and well-being measures (e.g., grades, substance use). Chi-square and logistic regression analyses were used; the latter controlled for gender, race/ethnicity, school grade, and family structure.

Results

More adolescents with ARPG than LRG reported regular smoking, heavy smoking, early smoking onset, no smoking quit attempts, and parental approval of smoking. ARPG and LRG adolescents who smoked were more likely to report poor grades, lifetime use of marijuana and other drugs, current heavy alcohol use, current caffeine use, depression, and aggressive behaviors and less likely to report participation in extracurricular activities. The association between not participating in extracurricular activities and smoking was statistically stronger in the LRG compared to the ARPG groups. Post-hoc analyses implicated a range of extracurricular activities including team sports, school clubs, and church activities.

Conclusions

Smoking was associated with poorer health-related behaviors in both ARPG and LRG groups. Interventions with adolescents may benefit from targeting both smoking and gambling.

•

We examined adolescent health behaviors by smoking status and gambling severity.

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Smoking was associated with poorer health behaviors for adolescent gamblers.

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Considering smoking may be helpful in interventions with adolescent gamblers.

Relationship between frequency and intensity of cigarette smoking and TTFC/C among students of the GYTS in select countries, 2007-2009

BACKGROUND

This study assessed the construct validity of a measure of nicotine dependence that was used in the Global Youth Tobacco Survey (GYTS).

METHODS

Using 2007-2009 data from the GYTS, subjects from 6 countries were used to assess current smokers' odds of reporting time to first cigarette or craving positive (TTFC/C+) by the number of cigarette smoking days per month (DPM) and the number of cigarettes smoked per day (CPD).

RESULTS

The percentage of GYTS smokers who reported TTFC/C+ ranged from 58.0% to 69.7%. Compared with students who smoked on 1-2 DPM, those who smoked on 3-9 DPM had 3 times the adjusted odds of reporting TTFC/C+. The adjusted odds of reporting TTFC/C+ were 3 to 7 times higher among those who smoked 10-29 DPM and 6 to 20 times higher among daily smokers. Similarly, the adjusted odds of TTFC/C+ were 3-6 times higher among those who smoked 2-5 CPD and 6 to 20 times higher among those who smoked >6 CPD, compared to those who smoked <1 CPD.

CONCLUSION

Associations of TTFC/C+ prevalence with both frequency and intensity of cigarette smoking provide a construct validation of the GYTS question used to assess respondents' TTFC/C status.

Health behaviors and related demographic factors among Korean adolescents

PURPOSE

The purposes of this study were to explore health behaviors, examine health behaviors in relation to demographic factors, and investigate the relationships between health risk behaviors (e.g., tobacco use, alcohol consumption, and sexual experience) among Korean adolescents.

METHODS

The study used a cross-sectional descriptive relational design and a population-based data collection of 1,716 middle and high school Korean adolescents. The 72-item Korean Adolescent Health Behavior Scale was used for data collection, while descriptive statistics, t test and chi-square test were used in the data analyses.

RESULTS

Females were doing better on weight control, hygiene, safety, and computer use than were males. Males were doing better on physical activity. Adolescents living in cities were more likely to be addicted to computer but were consuming alcohol and using tobacco less than adolescents in rural areas were. In addition, religion, grade level, and living area also made the adolescents' health behavior significantly different.

CONCLUSION

As the result suggested, gender, religion, grade level, and region need to be considered when designing health promotion interventions among Korean adolescents.

Normative influences on intentions to smoke among Greek adolescents: the moderating role of smoking status

Background

Social norms influence adolescent smoking intentions, but this effect may differentiate depending on current smoking experiences. The presented study assessed the moderation effects of smoking status on the relationship between social norms and smoking intentions among Greek adolescents.

Methods

A cross-section survey-based design was used. Overall, 251 Greek secondary school students (M age = 16.1 years, 61.2% females) completed structured and anonymous questionnaires including demographic characteristics (age, gender), subjective and descriptive social norms towards smoking, self-reported tobacco use, and intentions to smoke in the next 12 months.

Results

Linear regression analysis showed that social norms overall predicted 36.4% (Adjusted R²) of the variance in intentions. Perceived prevalence of smoking in same age peers and adults, having more close friends who smoke and perceived social approval of smoking predicted intentions to smoke in one year. Moderated regression analysis showed that the effects of social norms on smoking intentions were significantly moderated by smoking status.

Conclusions

Social norms predict smoking intentions, but this effect is stronger among ever (than never) smoker adolescents. Adolescents with smoking experiences may selectively attend to pro-smoking social cues and this perpetuates into their motivation to keep up the habit. School-based interventions should target normative beliefs and related cognitive processes, especially among adolescents who have already initiated tobacco use.

Persistent disparity in prevalence of current cigarette smoking between US adolescents with vs. without a past-year major depressive episode

Using data from annual (2004-2010) cross-sectional surveys of nationally representative samples, the prevalence rate of current (i.e., past 30 days) cigarette smoking among US adolescents age 12-17 years was twice as high for those with vs. without a past-year major depressive episode (PYMDE) (22 vs. 11% in the 2004 survey and 16 vs. 8% in the 2010 survey). The proportion of all US adolescent current smokers who had a PYMDE was about 24% for females; 70-80% of all smokers with PYMDE were females. The persistently higher smoking rates in US adolescents with vs. without PYMDE emphasizes the need for interventions.

Experimentation and use of cigarette and other tobacco products among adolescents in the Brazilian state capitals (PeNSE 2012)

INTRODUCTION: Nicotine dependence establishes itself more rapidly among adolescents than among adults. Tobacco occupies the fourth place in the rank of main risk factors for non-communicable diseases in the continent. Studies reveal that other forms of tobacco use have increased among adolescents. METHODS: Were included the 9th grade students from the 26 State Capitals and the Federal District. who were participants of the National Adolescent School-based Health Survey (PeNSE), in 2012. Factors independently associated with experimentation and regular use of cigarettes were investigated by means of multinomial logistic regression, using as reference "never tried a cigarette". The use of other tobacco products included cigar, pipe, narghile and others. RESULTS: Of the in the 61,037 participants in the 26 Brazilian capitals and the Federal District, 22.7% (95%CI 21.7 - 23.5) had experimented cigarettes, 6.1% (95%CI 5.6 - 6.6) are regular smokers and 7.1% (95%CI 6.5 - 7.7) had used other tobacco products, with half of them also being regular smokers. The chances of experimenting and being a regular smoker increased with age and according to the frequency of weekly exposure to other smokers. These chances were also higher among students who worked, who lived in monoparental families or without their parents, and those who felt that their parents would not mind if they smoked. CONCLUSION: Results reinforce the association between social disadvantages and experimenting and regular smoking. In addition, the use of other tobacco products is worthy of attention and may lead to regular smoking.

Socioeconomic inequalities in youth smoking in Brazil

OBJECTIVE

The contribution of smoking to socioeconomic inequalities in health is increasing worldwide, including in Brazil. Youth smoking may play an important role in the increasing social inequalities related to smoking. This study investigates social determinants of smoking among 15-year-old to 19-year-old individuals.

DESIGN

Cross-sectional study.

SETTING

The study uses data of 3536 participants aged 15-19 years of age of the Global Adult Tobacco Survey (GATS) and the National Household Sample Survey (Pesquisa Nacional por Amostragem de Domicilio, PNAD) obtained from household interviews. Smoking was defined as currently smoking tobacco products, regardless of frequency. Household socioeconomic indicators included per capita income, the educational level and sex of the head of the household, the presence of smoking restrictions and the number of smokers (excluding adolescents). Adolescent social factors included years of delaying school and social status (full-time student, working, and neither working nor studying). The hierarchical logistic regression analysis considered the effect of the complex sampling design.

RESULTS

From 3536 participants, 6.2% were smokers (95% CI 5.4 to 7.1). More men than women had the habit of smoking (7.2%; 5.9 to 8.6 vs 3.6%; 2.7 to 4.6). The likelihood of smoking was significantly greater for men and older teens. There was an upward trend in the OR of smoking according to the number of smokers in the house. Adolescents living in households with no smoking restrictions had a greater likelihood of being smokers. OR of smoking rose as the number of years of delaying school increased, being about three times greater among adolescents who were working and five times greater among those who were neither studying nor working.

CONCLUSIONS

Results demonstrate that socioeconomic inequality in smoking is established at younger ages and that school delay as well as school abandonment may contribute to increased smoking-related inequalities. Smoking restrictions at home were protective against adolescents becoming smokers. Living with other smokers was a strong predictor of adolescents becoming smokers.

Predictors of smoking relapse in a cohort of adolescents and young adults in Monastir (Tunisia)

BACKGROUND

Smoking prevalence in adolescents and young adults is substantially elevated in Tunisia. Moreover, there is a lack of knowledge regarding the effectiveness and associated factors in smoking cessation interventions among adolescents and young adults. This study aims at identifying the major factors leading to smoking relapse among adolescents and young adults in the region of Monastir, Tunisia.

METHODS

We carried out a prospective cohort study at the smoking cessation center of the University hospital of Monastir, Tunisia. The population study consisted of all adolescents and young adults (15-30 years) consulted during a period of two years (2009 - 2010). A questionnaire was used to explore the patient's sociodemographic characteristics, smoking history, nicotine dependence (Fagerstrom test) and anxiety / depression (Hospital Anxiety and Depression Scale). A telephone survey was conducted in July 2011 to assess smoking cessation results. A multivariate Cox regression was used to identify predictors of smoking relapses.

RESULTS

A total of 221 adolescents and young adults were included in this study with a mean age of 25.5 ± 3.9 years. At follow up, 59 study participants (26.7%) were abstinent and the overall median abstinence was 2 months. In the multivariate analysis smoking relapse was associated with being an adolescent patient (HR 2.16; 95% CI: 1.54-3.05), medium or higher nicotine dependence at baseline (HR 2.66, 95% CI: 1.06-7.05 and HR 3.12, 95% CI: 1.20-8.12 respectively), not receiving treatment (HR 1.70, 95% CI: 1.25-2.33) and have friend who is a smoker (HR 1.63; 95% CI: 0.96-2.79).

CONCLUSION

The results of this study provide important information about beneficial effect of smoking cessation support for adolescent and young adults. More efforts must be deployed to deal with contributing factors to smoking relapse.

A history of ashes: an 80 year comparative portrait of smoking initiation in American Indians and Non-Hispanic whites--the Strong Heart Study

The consequences of starting smoking by age 18 are significant. Early smoking initiation is associated with higher tobacco dependence, increased difficulty in smoking cessation and more negative health outcomes. The purpose of this study is to examine how closely smoking initiation in a well-defined population of American Indians (AI) resembles a group of Non-Hispanic white (NHW) populations born over an 80 year period. We obtained data on age of smoking initiation among 7,073 AIs who were members of 13 tribes in Arizona, Oklahoma and North and South Dakota from the 1988 Strong Heart Study (SHS) and the 2001 Strong Heart Family Study (SHFS) and 19,747 NHW participants in the 2003 National Health Interview Survey. The participants were born as early as 1904 and as late as 1985. We classified participants according to birth cohort by decade, sex, and for AIs, according to location. We estimated the cumulative incidence of smoking initiation by age 18 in each sex and birth cohort group in both AIs and NHWs and used Cox regression to estimate hazard ratios for the association of birth cohort, sex and region with the age at smoking initiation. We found that the cumulative incidence of smoking initiation by age 18 was higher in males than females in all SHS regions and in NHWs (p < 0.001). Our results show regional variation of age of initiation significant in the SHS (p < 0.001). Our data showed that not all AIs (in this sample) showed similar trends toward increased earlier smoking. For instance, Oklahoma SHS male participants born in the 1980s initiated smoking before age 18 less often than those born before 1920 by a ratio of 0.7. The results showed significant variation in age of initiation across sex, birth cohort, and location. Our preliminary analyses suggest that AI smoking trends are not uniform across region or gender but are likely shaped by local context. If tobacco prevention and control programs depend in part on addressing the origin of AI smoking it may be helpful to increase the awareness in regional differences.

Alcohol and drug use prevalence and factors associated with the experience of alcohol use in Iranian adolescents

Background

Alcohol and other drugs use is a problem among adolescents leading to numerous physical, social, and educational damages.

Objective

For determining the prevalence of alcohol and other substance use as well as the factors associated with the experience of alcohol use in adolescents.

Patients and Methods

This is a population-based and cross-sectional study, which was conducted in August 2010 on adolescents aged 15–18 years in Tehran. Data were collected by a Youth Risk Behavior Surveillance System (YRBSS) in 1,201 adolescents. The multistage cluster sampling method was used. Questions belonging to the domain of alcohol and other substance use were analyzed.

Results

In general, 15.1% of adolescents had experienced alcohol, which is significantly higher in boys (21.9%) compared to girls (8.4%) (P = 0.000). 3.1% of adolescents had experience using opium and marijuana. 5.6% had used ecstasy. The results of multivariate logistic regression indicated that low parental control rather than medium control [AOR: 0.09], lifetime cigarette use [AOR: 10.41], having a tobacco user friend [AOR: 4.36], and having an alcohol user friend [AOR: 5.84] are factors that are significantly related to the experience of alcohol use in female adolescents. In addition, studying in private schools rather than public schools [AOR: 3.46], lifetime cigarette use [AOR: 3.41], lifetime water pipe use [AOR: 4.43], experience of sexual activity [AOR: 8.52], having an alcohol user friend [AOR: 12.60], and having a water pipe user in family [AOR: 2.98] are factors that are significantly related to the experience of alcohol use in male adolescents.

Conclusions

We recommend interventional plans based gender aimed at improving adolescent health with regard substance abuse.

Substanzkonsum und substanzbezogene Störungen in Deutschland im Jahr 2012

Ziel: Untersucht wurden Umfang, Konsummuster und Störungen im Zusammenhang mit dem Gebrauch von Alkohol, Tabak, illegalen Drogen und Medikamenten. Methodik: Die Stichprobe des Epidemiologischen Suchtsurveys (ESA) 2012 wurde zufällig aus den Einwohnermelderegistern gezogen und umfasste 9084 Personen im Alter zwischen 18 und 64 Jahren. Die Befragung erfolgte schriftlich, telefonisch bzw. über das Internet; die Antwortrate lag bei 53.6 %. Ergebnisse: Bezogen auf die letzten 30 Tage zeigten 57.3 % der Befragten einen risikoarmen und 14.2 % einen riskanten Alkoholkonsum. Insgesamt 30.2 % gaben an, in diesem Zeitraum geraucht zu haben. In den letzten 12 Monaten haben 4.5 % der Befragten Cannabis, 0.8 % Kokain und 0.7 % Amphetamine konsumiert. Schmerzmittel waren die am häufigsten eingenommenen Medikamente (12-Monats-Prävalenz: 61.9 %). Schätzungen zur Substanzabhängigkeit nach DSM-IV ergaben Prävalenzwerte von 3.4 % für Alkohol, 10.8 % für Tabak, 0.5 % für Cannabis, 0.2 % für Kokain, 0.1 % für Amphetamine und 3.4 % für Schmerzmittel. Schlussfolgerungen: Die hohe Verbreitung psychischer Störungen durch Alkohol und Tabak macht die Dringlichkeit der Umsetzung effizienter Präventionsmaßnahmen deutlich. Störungen im Zusammenhang mit Medikamenten sollten stärker beachtet werden.

Sensation-seeking predicts initiation of daily smoking behavior among American Indian high school students

PURPOSE

American Indian (AI) youth have a high risk of smoking initiation. Sensation-seeking, defined as the tendency to seek novel and thrilling experiences, has been associated with smoking initiation in other groups but has never been examined in AI youth.

METHODS

Data were from the Voices of Indian Teens Project (VOICES), a longitudinal study of AI youth from seven high schools in four AI communities in the western United States. Participants completed annual surveys in school over a three-year period. Our sample comprised 764 students who were non-smokers at baseline. Smoking initiation was defined as endorsement of daily smoking after baseline. We used binary logistic regression to evaluate the association of baseline sensation-seeking with odds of daily smoking initiation, stratified by gender.

RESULTS

Participants were 353 males and 411 females aged 13 to 21years at baseline. After adjusting for covariates, baseline sensation-seeking correlated with smoking initiation differently in males and females. Sensation-seeking did not predict daily smoking in males. Among females, however, higher sensation-seeking scores at baseline predicted daily smoking in both the unadjusted (odds ratio=1.4; 95% CI=1.1-1.8; p=0.005) and covariate-adjusted (odds ratio=1.3; 95% CI=1.0-1.6; p=0.04) models.

CONCLUSION

Gender-specific prevention programs may be warranted in addressing different risk-factor profiles in this high-risk population.

Late-onset smokers: How many, and associations with health behaviours and socioeconomic status

Aims: Adolescence is considered a critical phase for smoking initiation, while smoking initiation in adulthood has received less attention. In the present study, we investigated smoking initiation in early adulthood, with an additional focus on how socioeconomic status (SES) relates to late-onset smoking. Methods: The Norwegian Longitudinal Health Behaviour Study followed a representative sample of adolescents ( n=530) from age 13 (7th grade) to age 30 (years 1990–2007) through 9 waves of data collection. Information was collected on the adolescents’ gender, smoking, alcohol use, cannabis use, physical activity, and SES. Those reporting to be smokers at age 30, but not at age 18, were defined as “late-onset smokers”. Results: At age 30, 21% were daily smokers, of which 45% met our definition of late-onset smoking. Participants with a low SES had a higher odds ratio for late-onset smoking (OR=3.42) and a lower odds ratio for quitting smoking (OR=0.40) after adjusting for confounders. Conclusions: Early adulthood is an additional critical phase for daily smoking initiation. The clear and consistent negative association between SES and late-onset smoking, as well as the positive association between SES and smoking cessation, contribute to the association between SES and smoking in the general adult population.

The Minnesota Adolescent Community Cohort Study: design and baseline results

The Minnesota Adolescent Community Cohort (MACC) Study is a population-based, longitudinal study that enrolled 3,636 youth from Minnesota and 605 youth from comparison states ages 12 to 16 years in 2000-2001. Participants have been surveyed by telephone semi-annually about their tobacco-related attitudes and behaviors. The goals of the study are to evaluate the effects of the Minnesota Youth Tobacco Prevention Initiative and its shutdown on youth smoking patterns, and to better define the patterns of development of tobacco use in adolescents. A multilevel sample was constructed representing individuals, local jurisdictions and the entire state, and data are collected to characterize each of these levels. This paper presents the details of the multilevel study design. We also provide baseline information about MACC participants including demographics and tobacco-related attitudes and behaviors. This paper describes variability in smoking prevalence and demographic characteristics for local units, and compares MACC participants to the state as a whole.

Age of onset and timing of treatment for mental and substance use disorders: implications for preventive intervention strategies and models of care

PURPOSE OF REVIEW

To provide an update of the recent studies on the age of onset of the major mental illnesses, with a special focus on the prospects for prevention and early intervention.

RECENT FINDINGS

The studies reviewed here confirm previous reports on the age of onset of the major mental disorders. While the behaviour disorders, and certain anxiety disorders, emerge during childhood, most of the high prevalence disorders (anxiety, mood and substance use) emerge during adolescence and early adulthood, as do the psychotic disorders. Early age of onset has been shown to be associated with a longer duration of untreated illness and poorer clinical and functional outcomes.

SUMMARY

Although the onset of most mental disorders usually occurs during the first three decades of life, effective treatment is typically not initiated until a number of years later. Although there is increasing evidence to suggest that intervention during the early stages of a disorder may help reduce the severity and/or the persistence of the initial or primary disorder and prevent secondary disorders, additional research is needed into appropriate treatment for early stage cases as well as the long-term effects of early intervention, and to appropriate service design for those in the early stages of a mental illness. This will mean not only the strengthening and re-engineering of existing systems but also, crucially, the construction of new streams of care for young people in transition to adulthood.

Reliability and validity of self-reported smoking in an anonymous online survey with young adults

OBJECTIVE

The Internet offers many potential benefits to conducting smoking and other health behavior research with young adults. Questions, however, remain regarding the psychometric properties of online self-reported smoking behaviors. The purpose of this study was to examine the reliability and validity of self-reported smoking and smoking-related cognitions obtained from an online survey.

METHODS

Young adults (N = 248) age 18 to 25 who had smoked at least 1 cigarette in the past 30 days were recruited online and completed a survey of tobacco and other substance use.

RESULTS

Measures of smoking behavior (quantity and frequency) and smoking-related expectancies demonstrated high internal consistency reliability. Measures of smoking behavior and smoking stage of change demonstrated strong concurrent criterion and divergent validity. Results for convergent validity varied by specific constructs measured. Estimates of smoking quantity, but not frequency, were comparable to those obtained from a nationally representative household interview among young adults.

CONCLUSIONS

These findings generally support the reliability and validity of online surveys of young adult smokers. Identified limitations may reflect issues specific to the measures rather than the online data collection methodology. Strategies to maximize the psychometric properties of online surveys with young adult smokers are discussed.

TTC12-ANKK1-DRD2 and CHRNA5-CHRNA3-CHRNB4 influence different pathways leading to smoking behavior from adolescence to mid-adulthood

BACKGROUND

CHRNA5-CHRNA3-CHRNB4 and TTC12-ANKK1-DRD2 gene-clusters influence smoking behavior. Our aim was to test developmental changes in their effects as well as the interplays between them and with nongenetic factors.

METHODS

Participants included 4762 subjects from a general population-based, prospective Northern Finland 1966 Birth Cohort (NFBC 1966). Smoking behavior was collected at age 14 and 31 years. Information on maternal smoking, socioeconomic status, and novelty seeking were also collected. Structural equation modeling was used to construct an integrative etiologic model including genetic and nongenetic factors.

RESULTS

Several single nucleotide polymorphisms in both gene-clusters were significantly associated with smoking. The most significant were in CHRNA3 (rs1051730, p = 1.1 × 10(-5)) and in TTC12 (rs10502172, p = 9.1 × 10(-6)). CHRNA3-rs1051730[A] was more common among heavy/regular smokers than nonsmokers with similar effect-sizes at age 14 years (odds ratio [95% CI]: 1.27 [1.06-1.52]) and 31 years (1.28 [1.13-1.44]). TTC12-rs10502172[G] was more common among smokers than nonsmokers with stronger association at 14 years (1.33 [1.11-1.60]) than 31 years (1.14 [1.02-1.28]). In adolescence, carriers of three-four risk alleles at either CHRNA3-rs1051730 or TTC12-rs10502172 had almost threefold odds of smoking regularly than subjects with no risk alleles. TTC12-rs10502172 effect on smoking in adulthood was mediated by its effect on smoking in adolescence and via novelty seeking. Effect of CHRNA3-rs1051730 on smoking in adulthood was direct.

CONCLUSIONS

TTC12-ANKK1-DRD2s seemed to influence smoking behavior mainly in adolescence, and its effect is partially mediated by personality characteristics promoting drug-seeking behavior. In contrast, CHRNA5-CHRNA3-CHRNB4 is involved in the transition toward heavy smoking in mid-adulthood and in smoking persistence. Factors related to familial and social disadvantages were strong independent predictors of smoking.

Cigarette advertising and teen smoking initiation

OBJECTIVE

To test the specificity of the association between cigarette advertising and adolescent smoking initiation.

METHODS

A longitudinal survey of 2102 adolescents, aged 10 to 17 years at baseline, who never smoked was conducted by using masked images of 6 cigarette advertisements and 8 other commercial products with all brand information digitally removed. The exposure variable was a combination of contact frequency and cued recall of brands for cigarette and other advertisements. Multilevel mixed-effects Poisson regressions were used to assess smoking initiation 9 months after the baseline assessment as a function of cigarette-advertisement exposure, other advertisement exposure, and baseline covariates.

RESULTS

Thirteen percent (n = 277) of students initiated smoking during the observation period. Although the incidence of trying smoking was associated with increased exposure to cigarette advertisements (10% in the low, 12% in the medium, and 19% in the high cigarette-advertisement exposure tertile initiated smoking), exposure to other advertisements did not predict smoking initiation. Compared with low exposure to cigarette advertisements, high exposure remained a significant predictor of adolescent smoking initiation after controlling for baseline covariates (adjusted relative risk: 1.46 [95% confidence interval: 1.08-1.97]; P < .05).

CONCLUSIONS

Our results support the notion of a content-related effect of cigarette advertisements and underlines the specificity of the relationship between tobacco marketing and teen smoking; exposure to cigarette advertisements, but not other advertisements, is associated with smoking initiation.

Adolescent brain development, risk-taking and vulnerability to addiction

Adolescents (12-18 years old) and young adults (18-25 years old), are more likely than older adults to drive-or agree to be driven-recklessly or while intoxicated, to use illicit or dangerous substances and to engage in both minor and more serious antisocial behaviour. Numerous factors during adolescence may lead to or favour initiation of drug use, such as sensation-seeking, gregariousness and social conformity. These aspects, however, cannot be dissociated from the increased sex drive and quest for an integrated self. In the separation-individuation process, relationships with peers play many different roles: a field for experimentation, emotional support, a place for "projection" and "identification", and the possibility of finding a partner. Unsurprisingly, therefore, drug use generally takes place in a group setting. Despite evidence of heightened real-world risk-taking, laboratory studies have yet to yield consistent evidence that adolescents, when on their own, are more inclined towards risky behaviour than their elders. Moreover, their comprehension and reasoning abilities in risky decision-making situations are roughly equivalent to those of adults. Structural and functional neuroimaging studies have shown that neural circuitry undergoes major reorganization during adolescence, particularly in those regions of the brain relating to executive functions, the self and social cognition, and that the "emotional brain" may play a role in that reorganization. Age-related decreases in gray matter volume mainly reflect a reduction in the number of synapses and the complexity of axonal ramifications. By 18-20 years old, most of the subcortical white matter and association pathways have reached a plateau. Risk-taking behavior and novelty-seeking may provide, with an appropriate feed back, a mechanism to optimize brain development in adolescence.