The relationship of early-onset regular smoking to alcohol use, depression, illicit drug use, and other risky behaviors during early adolescence: results from the youth supplement to the third national health and nutrition examination survey

Be more mindful: Targeting addictive responses by integrating mindfulness with cognitive bias modification or cue exposure interventions

This review provides an overview of the most prominent neurocognitive effects of cognitive bias modification (CBM), cue-exposure therapy and mindfulness interventions for targeting addictive responses. It highlights the key insights that have stemmed from cognitive neuroscience and brain imaging research and combines these with insights from behavioural science in building a conceptual model integrating mindfulness with response-focused CBM or cue-exposure interventions. This furthers our understanding of whether and how mindfulness strategies may i) facilitate or add to the induced response-focused effects decreasing cue-induced craving, and ii) further weaken the link between craving and addictive responses. Specifically, awareness/monitoring may facilitate, and decentering may add to, response-focused effects. Combined awareness acceptance strategies may also diminish the craving-addiction link. The conceptual model presented in this review provides a specific theoretical framework to deepen our understanding of how mindfulness strategies and CBM or cue-exposure interventions can be combined to greatest effect. This is important in both suggesting a roadmap for future research, and for the further development of clinical interventions.

The association of adolescents' smoking with the physical activity levels of their friends

BACKGROUND

Smoking is inversely related to people's Physical Activity Level (PAL). As the behavior of friends may affect the choices and behavior of adolescents, having friends with a high PAL may potentially protect against adolescent smoking. This study aims to assess whether adolescents' smoking is associated with the PAL of their friends.

METHODS

SILNE-R survey data of 11.918 adolescents from 55 different schools in 7 European cities was used to determine weekly smoking, individual PAL, PAL of friends, school PAL, and smoking of friends. Multilevel, multivariable logistic regression analysis were used to assess the association between the PAL of friends and weekly smoking. Several socio-demographic variables were included as covariates in the analysis.

RESULTS

Our results indicated that 10.8% of the respondents was smoking weekly. Weekly smoking was most common among adolescents whose friends had a PAL of 0-42.0 min per day (14.5%). Respondents were significantly more likely to be smoking weekly if their friends were on average 0-42 min vs. 80-180 min physically active (OR 1.27 [95% CI 1.04-1.55]). This association existed independently of the individual PAL of respondents. Stratification for smoking of friends yielded equal results, although the association appeared to be somewhat stronger for those with smoking friends (OR 1.38 [95% CI 1.06-1.82]).

CONCLUSION

Adolescents are less likely to smoke weekly if they associate with friends who spend >80 min per day on physical activity. Initiatives aimed at the prevention of smoking among adolescents may benefit from organizing group-based physical activity programs.

Personality-specific pathways from bullying victimization to adolescent alcohol use: a multilevel longitudinal moderated mediation analysis

Bullying victimization is common in adolescence and has been associated with a broad variety of psychopathology and alcohol use. The present study assessed time-varying associations between bullying victimization and alcohol use through internalizing and externalizing symptoms and whether this indirect association throughout time is moderated by personality. This 5-year longitudinal study (3,800 grade 7 adolescents) used Bayesian multilevel moderated mediation models: independent variable was bullying victimization; moderators were four personality dimensions (anxiety sensitivity, hopelessness, impulsivity, and sensation seeking); internalizing symptoms (anxiety, depressive symptoms) and externalizing symptoms (conduct, hyperactivity problems) were the mediators; and alcohol use, the outcome. Results indicated significant between, within, and lagged effects on alcohol use through internalizing and externalizing symptoms. There were significant between and within effects on alcohol use through internalizing symptoms for adolescents with high anxiety sensitivity and hopelessness, and significant between, within, and lagged effects on alcohol use through externalizing symptoms for adolescents with high impulsivity and sensation seeking. These findings implicate two risk pathways that account for how bullying victimization enhances alcohol use risk and emphasize the importance of personality profiles that can shape the immediate and long-term consequences of victimization.

The intersection of internalizing symptoms and alcohol use during the COVID-19 pandemic: A prospective cohort study

Given the well-established relationship between alcohol and internalizing symptoms, potential increases in depression and anxiety during the COVID-19 pandemic may lead to increases in alcohol consumption and binge drinking. This study examines this association from before to during two phases of the pandemic in a cohort of Canadian youth. We used linked data from a sub-sample of 1901 secondary school students who participated in three consecutive school years of the Cannabis use, Obesity, Mental health, Physical activity, Alcohol use, Smoking, and Sedentary behaviour (COMPASS) study between 2018/19 and 2020/21. Separate multilevel logistic regression models examined the association between depression and anxiety symptoms with odds of escalation and reduction (vs. maintenance) and initiation (vs. abstinence) of alcohol consumption. Results show that depression and anxiety symptoms significantly increased over the three years, and these changes were moderated by changes in alcohol consumption and binge drinking. Students with increased depression symptoms were less likely to reduce their alcohol consumption in the early pandemic (Adjust odds ratio [AOR] 0.94, 95% CI:0.90-0.98), more likely to initiate alcohol consumption in the ongoing pandemic period (AOR 1.03, 95% CI: 1.01-1.05), and more likely to initiate binge drinking in both periods. The depression-alcohol use association was stronger among females than males. This study demonstrates a modest association between internalizing symptoms and alcohol use, particularly for depression symptoms and in females. The identified depression-alcohol use association suggests that preventing or treating depression might be beneficial for adolescent alcohol use and vice versa.

Age-Dependent and Pathway-Specific Bimodal Action of Nicotine on Synaptic Plasticity in the Hippocampus of Mice Lacking the miR-132/212 Genes

Nicotine addiction develops predominantly during human adolescence through smoking. Self-administration experiments in rodents verify this biological preponderance to adolescence, suggesting evolutionary-conserved and age-defined mechanisms which influence the susceptibility to nicotine addiction. The hippocampus, a brain region linked to drug-related memory storage, undergoes major morpho-functional restructuring during adolescence and is strongly affected by nicotine stimulation. However, the signaling mechanisms shaping the effects of nicotine in young vs. adult brains remain unclear. MicroRNAs (miRNAs) emerged recently as modulators of brain neuroplasticity, learning and memory, and addiction. Nevertheless, the age-dependent interplay between miRNAs regulation and hippocampal nicotinergic signaling remains poorly explored. We here combined biophysical and pharmacological methods to examine the impact of miRNA-132/212 gene-deletion (miRNA-132/212-/-) and nicotine stimulation on synaptic functions in adolescent and mature adult mice at two hippocampal synaptic circuits: the medial perforant pathway (MPP) to dentate yrus (DG) synapses (MPP-DG) and CA3 Schaffer collaterals to CA1 synapses (CA3-CA1). Basal synaptic transmission and short-term (paired-pulse-induced) synaptic plasticity was unaltered in adolescent and adult miRNA-132/212-/- mice hippocampi, compared with wild-type controls. However, nicotine stimulation promoted CA3-CA1 synaptic potentiation in mature adult (not adolescent) wild-type and suppressed MPP-DG synaptic potentiation in miRNA-132/212-/- mice. Altered levels of CREB, Phospho-CREB, and acetylcholinesterase (AChE) expression were further detected in adult miRNA-132/212-/- mice hippocampi. These observations propose miRNAs as age-sensitive bimodal regulators of hippocampal nicotinergic signaling and, given the relevance of the hippocampus for drug-related memory storage, encourage further research on the influence of miRNAs 132 and 212 in nicotine addiction in the young and the adult brain.

Role of genetic background in the effects of adolescent nicotine exposure on mesolimbic dopamine transmission

Smoking during adolescence may increase the likelihood to develop nicotine dependence and to abuse other drugs such as cocaine. Despite great efforts to understand underlying neurobiological mechanisms of this progression, less attention has been paid to the role of genetic factors. Here, we investigated the influence of both genetic background and age at first nicotine exposure in the long-lasting effects on mesolimbic dopamine transmission including the increased cocaine-rewarding effect. Mid-adolescent and adult rats of inbred strains Lewis (addiction prone) and Fischer 344 (addiction resistant) were administered nicotine (0.4 mg/kg) or vehicle once daily for 5 days. Changes in dopamine transmission were investigated by in vivo microdialysis and electrophysiology after 30 days of withdrawal, whereas changes in cocaine-rewarding effect were assessed via conditioned place preference paradigm. Nicotine pre-exposure differentially changed mesolimbic dopamine transmission depending on strain and age of pre-exposure. A potentiation of dopamine response to nicotine was observed in nucleus accumbens (NAc) core of both strains and age groups, whereas dopamine response in NAc shell was enhanced exclusively in Lewis rats exposed to nicotine during adolescence. A similar response was observed following cocaine challenge at adulthood. Changes in VTA dopamine cell population and activity were observed only in adolescent nicotine-pretreated Lewis rats, which also showed an increased cocaine-rewarding effect at adulthood. These results highlight the influence of genetic background in the long-lasting effects of nicotine exposure and suggest that exposure during adolescence might increase nicotine and cocaine-rewarding properties in genetically vulnerable individuals, thereby facilitating progression toward dependence.

Unique, long-term effects of nicotine on adolescent brain

Adolescence is a time of major plasticity of brain systems that regulate motivated behavior and cognition, and is also the age of peak onset of nicotine use. Although there has been a decline in teen use of cigarettes in recent years, there has been a huge increase in nicotine vaping. It is therefore critically important to understand the impact of nicotine on this critical phase of brain development. Animal studies have shown that nicotine has unique effects on adolescent brain. The goal of this review is therefore to systematically evaluate age- and sex-differences in the effects of nicotine on brain and behavior. Both acute and chronic effects of nicotine on brain biochemistry and behavior, particularly drug reward, aversion, cognition and emotion, are evaluated. Gaps in our current knowledge that need to be addressed are also highlighted. This review compares and integrates human and animals findings. Although there can be no experimental studies in humans to confirm similar behavioral effects of teen nicotine exposure, an emerging observational literature suggests similarities across species. Given the substantial evidence for long-term negative impact of adolescent nicotine exposure on brain and behavior, further longitudinal assessment of health outcomes in teen and young adult e-cigarette users is warranted.

Refinement of cg05575921 demethylation response in nascent smoking

The initiation of adolescent smoking is difficult to detect using carbon monoxide or cotinine assays. Previously, we and others have shown that the methylation of cg05575921 is an accurate predictor of adult smoking status. But the dose and time dependency of the demethylation response to smoking initiation in adolescents is not yet well understood. To this end, we conducted three consecutive annual in-person interviews and biological samplings of 448 high school students (wave 1 (W1)-wave 3 (W3)). At W1 (n = 448), 62 subjects reported using tobacco and 72 subjects reported using cannabis at least once in their life-time with 38 and 20 subjects having a positive cotinine and cannabinoid levels, respectively, at W1 intake. At W3 (n = 383), 67 subjects reported using tobacco and 60 subjects reported using cannabis at least once with 75 and 60 subjects having positive cotinine and cannabinoid levels, respectively, at W3. Subjects with undetectable cotinine levels at all three-time waves had stable levels of cg05575921 methylation throughout the study (88.7% at W1 and 88.8% at W3, n = 149), while subjects with positive cotinine levels at all 3 time points manifested a steady decrease in cg05575921 methylation (81.8% at W1 and 71.3% at the W3, n = 12). In those subjects with an affirmative smoking self-report at W3 (n = 17), the amount of demethylation at cg05575921 was correlated with time and intensity of smoking. We conclude that cg05575921 methylation is a sensitive, dose-dependent indicator of early stages of smoking, and may help to identify smokers in the early stages of smoking.

African American adolescent substance use: The roles of racial discrimination and peer pressure

Peer pressure to use drugs and alcohol is one of the strongest predictors of adolescent substance use. In addition to this normative adolescent stressor, African American adolescents often also face race-related stress in the form of racial discrimination, which has been linked to maladaptive coping responses such as substance use. The interaction of these stressors may help explain substance using behaviors for African American adolescents. The present study explored the relationship between eighth-grade school-based racial discrimination experiences, peer pressure to use drugs and alcohol, and gender to predict 11th-grade marijuana and alcohol use (N = 610; 49% female). Logistic regression analyses indicated teacher- and peer-perpetrated racial discrimination experiences were related to higher alcohol use. Eighth-grade peer pressure to use drugs moderated the relations between teacher- and peer-perpetrated racial discrimination and 11th-grade marijuana use. Overall, results indicate that school-based racial discrimination increases risk for adolescent substance use, and peer pressure moderates this relation for multiple types of racial discrimination. No moderation by gender was found. The importance of considering race-related stress in conjunction with more general adolescent stress to understand African American adolescent substance use is discussed.

Adolescent drug exposure: A review of evidence for the development of persistent changes in brain function

Over the past decade, many studies have indicated that adolescence is a critical period of brain development and maturation. The refinement and maturation of the central nervous system over this prolonged period, however, makes the adolescent brain highly susceptible to perturbations from acute and chronic drug exposure. Here we review the preclinical literature addressing the long-term consequences of adolescent exposure to common recreational drugs and drugs-of-abuse. These studies on adolescent exposure to alcohol, nicotine, opioids, cannabinoids and psychostimulant drugs, such as cocaine and amphetamine, reveal a variety of long-lasting behavioral and neurobiological consequences. These agents can affect development of the prefrontal cortex and mesolimbic dopamine pathways and modify the reward systems, socio-emotional processing and cognition. Other consequences include disruption in working memory, anxiety disorders and an increased risk of subsequent drug abuse in adult life. Although preventive and control policies are a valuable approach to reduce the detrimental effects of drugs-of-abuse on the adolescent brain, a more profound understanding of their neurobiological impact can lead to improved strategies for the treatment and attenuation of the detrimental neuropsychiatric sequelae.

Childhood ADHD Symptoms and Future Illicit Drug Use: The Role of Adolescent Cigarette Use

Objectives

The aim of this study is to understand how early cigarette use might predict subsequent illicit drug use, especially among individuals with attention-deficit hyperactivity disorder (ADHD) symptoms during childhood.

Methods

Data were drawn from the National Longitudinal Study of Adolescent Health (Waves I-IV). The analysis sample involves participants who had not used illicit drugs at Wave I, with no missing responses for studied predictors (N = 7,332).

Results

Smoking status at Wave I (ever regular vs. never regular) and childhood ADHD symptoms predicted subsequent illicit drug use at Waves II to IV. No interaction effect of smoking status at Wave I and childhood ADHD symptoms was found. However, an indirect effect from childhood ADHD symptoms on illicit drug use was identified, through smoking status at Wave I. Similar results were observed for predicting illicit drug dependence.

Conclusions

The findings support the notion that smoking status during early adolescence may mediate the association between childhood ADHD symptoms and risk of later adult drug use. Interventions to prevent smoking among adolescents may be particularly effective at decreasing subsequent drug use, especially among children with ADHD symptoms.

Saliva DNA Methylation Detects Nascent Smoking in Adolescents

Objectives: Early identification of smoking, essential for the successful implementation of interventions, arrests the escalation of smoking and smoking-associated risk behaviors in adolescents. However, because nascent smoking is typically episodic and infrequent, enzyme-linked immunoassay reagent-based approaches that detect cotinine, a key nicotine metabolite, are not effective in identifying adolescents in the earliest stages of smoking. Epigenetic methods may offer an alternative approach for detecting early-stage smokers. In prior work, we and others have shown that the methylation status of cg05575921 of whole-blood DNA accurately predicts smoking status in regularly smoking adults and is sensitive to nascent smoking. Yet, the blood draws necessary to obtain DNA for this method may be poorly accepted by adolescents. Saliva could be an alternative source of DNA. However, the ability of saliva DNA methylation status to predict smoking status among adolescents is unknown. Methods: To explore the possibility of using salivary DNA for screening purposes, we examined the DNA methylation status at cg05575921 in saliva DNA samples from 162 high school aged subjects for whom we also had paired serum cotinine values. Results: Overall, the reliability of self-report of nicotine/tobacco use in these adolescents was poor with 67% of all subjects whose serum levels of cotinine was ≥2 ng/mL (n = 75) denying any use of nicotine-containing products in the past 6 months. However, the correspondence of the two biological measures of smoking was high, with serum cotinine positivity being strongly correlated with cg05575921 methylation (p < 0.0001). Receiver operating characteristic (ROC) analyses showed that cg05575921 methylation status could be used to classify those with positive serum cotinine values (≥2 ng/mL) from those denying smoking and have undetectable levels of cotinine. Conclusions: We conclude that saliva DNA methylation assessments hold promise as a means of detecting nascent smoking.

Is smoking heaviness causally associated with alcohol use? A Mendelian randomization study in four European cohorts

Background

Observational studies have shown that tobacco and alcohol use co-occur, but it is not clear whether this relationship is causal.

Methods

Using data from the Avon Longitudinal Study of Parents and Children (ALSPAC) and UK Biobank, we used observational methods to test the hypothesis that smoking heaviness increases alcohol consumption. Mendelian randomization (MR) analyses were then used to test the causal relationship between smoking heaviness and alcohol consumption using 55 967 smokers from four European studies [ALSPAC, The Nord-Trøndelag Health Study (HUNT), the Copenhagen General Population Study (CGPS) and UK Biobank]. MR analyses used rs1051730/rs16969968 as a genetic proxy for smoking heaviness.

Results

Observational results provided evidence of an association between cigarettes per day and weekly alcohol consumption (increase in units of alcohol per additional cigarette smoked per day = 0.10, 95% confidence interval (CI) 0.05 to 0.15, P ≤ 0.001 in ALSPAC; and 0.48, 95% CI 0.45 to 0.52, P ≤ 0.001 in UK Biobank). However, there was little evidence for an association between rs1051730/rs16969968 and units of alcohol consumed per week across ALSPAC, HUNT, CGPS and UK Biobank (standard deviation increase in units of alcohol per additional copy of the risk allele = –0.004, 95% CI –0.023 to 0.016, P=0.708, I² = 51.9%). We had 99% and 88% power to detect a change of 0.03 and 0.02 standard deviation units of alcohol per additional copy of the risk allele, respectively.

Conclusions

Previously reported associations between smoking and alcohol are unlikely to be causal, and may be the result of confounding and/or reverse causation. This has implications for public health research and intervention research.

Advances in behavioral animal models of alcohol use disorder

Alcohol use disorder (AUD) is a multifaceted neuropsychiatric disease that combines behavioral, psychosocial, and neurobiological aspects. Over the previous decade, animal models have advanced in modeling the major psychological constructs that characterize AUD. These advances pave the road for more sophisticated behavioral models that capture addiction-related aspects, such as alcohol craving, compulsive seeking and intake, dependence, and relapse. In this review, we survey the recent progress in behavioral animal modeling of five aspects of AUD: alcohol consumption, dependence, and seeking; compulsivity in alcohol intake despite adverse outcomes; vulnerability and resilience factors in alcohol addiction; relapse despite treatment; and relapse prevention by manipulating alcohol-associated memory reconsolidation. These advances represent a general attempt to grasp the complexity and multidimensional nature of AUD, and to focus on behavioral characteristics that better reflect and model this disorder.

Oral contraceptive use and depression among adolescents

PURPOSE

Depression is a prevalent health problem affecting U.S. women. Oral contraceptive pills (OCPs) are commonly used for pregnancy prevention, and evidence is mixed regarding any increased risk for incident depression among users, particularly adolescents.

METHODS

We examined the relationship between OCP use and depressive disorders among female adolescents using validated, structured interview assessments in a general population sample of adolescents in the National Comorbidity Survey-Adolescent Supplement. Respondents were 4765 female adolescents with no history of pregnancy who reported current OCP use, lifetime OCP use, and age of OCP initiation. Lifetime and current depressive disorders, including major depressive disorder and depressive episodes, were assessed by lay interviewers.

RESULTS

In logistic regression models adjusted for a range of confounders, there was no relationship between ever using OCPs and lifetime depressive disorder (OR 1.10, 95% CI 0.88-1.37), nor current use of OCPs and current depressive disorder (OR 0.82, 95% CI 0.50-1.35). Using survival analysis for age-of-onset data, we found that OCP use is not associated with an increased risk of depressive disorders.

CONCLUSIONS

In sum, use of OCPs in a general population sample of adolescents did not increase the risk of depressive disorders.

Examining the Association and Directionality between Mental Health Disorders and Substance Use among Adolescents and Young Adults in the U.S. and Canada-A Systematic Review and Meta-Analysis

Background: The purpose of this systematic review was to examine the association and directionality between mental health disorders and substance use among adolescents and young adults in the U.S. and Canada. Methods: The following databases were used: Medline, PubMed, Embase, PsycINFO, and Cochrane Library. Meta-analysis used odds ratios as the pooled measure of effect. Results: A total of 3656 studies were screened and 36 were selected. Pooled results showed a positive association between depression and use of alcohol (odds ratio (OR) = 1.50, 95% confidence interval (CI): 1.24–1.83), cannabis (OR = 1.29, 95% CI: 1.10–1.51), and tobacco (OR = 1.65, 95% CI: 1.43–1.92). Significant associations were also found between anxiety and use of alcohol (OR = 1.54, 95% CI: 1.19–2.00), cannabis (OR = 1.36, 95% CI: 1.02–1.81), and tobacco (OR = 2.21, 95% CI: 1.54–3.17). A bidirectional relationship was observed with tobacco use at baseline leading to depression at follow-up (OR = 1.87, CI = 1.23–2.85) and depression at baseline leading to tobacco use at follow-up (OR = 1.22, CI = 1.09–1.37). A unidirectional relationship was also observed with cannabis use leading to depression (OR = 1.33, CI = 1.19–1.49). Conclusion: This study offers insights into the association and directionality between mental health disorders and substance use among adolescents and young adults. Our findings can help guide key stakeholders in making recommendations for interventions, policy and programming.

Association of Depression With Risk of Incident Systemic Lupus Erythematosus in Women Assessed Across 2 Decades

IMPORTANCE

It has long been hypothesized that depression may increase the risk of developing autoimmune disease; however, rigorous empirical evidence is sparse.

OBJECTIVE

To evaluate whether an association exists between depression and risk of incident systemic lupus erythematosus (SLE), a paradigmatic, systemic autoimmune disease.

DESIGN, SETTING, AND PARTICIPANTS

This 20-year prospective, longitudinal cohort study evaluated data collected from 2 cohorts of women participating in the Nurses' Health Study (1996-2012) and the Nurses' Health Study II (1993-2013). Data analyses were conducted from August 2017 to May 2018.

MAIN OUTCOMES AND MEASURES

Incident SLE with 4 or more American College of Rheumatology criteria was ascertained by self-report and confirmed by medical record review. Depression was assessed repeatedly throughout follow-up according to whether women reported having received a clinician's diagnosis of depression, regular antidepressant use, or a score of less than 60 on the 5-item Mental Health Inventory (MHI-5). Whether longitudinally assessed health risk factors (eg, cigarette smoking, body mass index, oral contraceptive use, menopause or postmenopausal hormone use, alcohol use, exercise, or diet) accounted for increased SLE risk among women with vs without depression was examined. Cox proportional hazards regression models were used to estimate risk of SLE. In addition, the association of depression lagged by 4 years, and depression status at baseline with incident SLE throughout follow-up was assessed.

RESULTS

Data from 194 483 women (28-93 years of age; 93% white) were included. During 20 years of follow-up, 145 cases of SLE occurred. Compared with women with no depression, women with a history of depression had a subsequent increased risk of SLE (HR, 2.67; 95% CI, 1.91-3.75; P < .001). Adjustment for body mass index, cigarette smoking, and oral contraception and postmenopausal hormone use slightly attenuated associations (adjusted HR, 2.45; 95% CI, 1.74-3.45; P < .001). The SLE risk was elevated with each of the 3 following depression indicators modeled separately: clinician's diagnosis of depression (HR, 2.19; 95% CI, 1.29-3.71), antidepressant use (HR, 2.80; 95% CI, 1.94-4.05), and MHI-5 scores indicating depressed mood (HR, 1.70; 95% CI, 1.18-2.44). Associations remained strong when depression status was lagged by 4 years with respect to the outcome (HR, 1.99; 95% CI, 1.32-3.00) and when depression status at baseline was used as the exposure (HR, 2.28; 95% CI, 1.54-3.37).

CONCLUSIONS AND RELEVANCE

This study contributes to increasing evidence that depression may be associated with increased risk of SLE and suggests that the association is not fully explained by measured health factors or behaviors.

Depressive symptoms and suicidal behaviours in adolescent non-daily smokers compared to daily smokers and never-smokers in Korea: National cross-sectional study

INTRODUCTION

We aimed to investigate the association of non-daily smoking with depressive symptoms and suicidal behaviours among adolescents by analysing data from the 2016 Korean Youth Risk Behavior Web-based Survey (KYRBWS), a national school-based survey.

METHODS

We analysed data from a nationally representative sample of Korean adolescents aged 12-18 years (n = 65,528). We investigated the risks of depressive symptoms, suicide ideation, plan and attempt in adolescent non-daily smokers using multiple logistic regression analyses after adjusting for confounding factors. Taking into account the trajectory of smoking patterns in adolescents, we assessed all analyses with stratification by early (aged 12-15) and late (aged 16-18) adolescents.

RESULTS

Among early adolescents, non-daily smokers were more likely to have depressive symptoms, suicide ideation and plan compared with never smokers and even more likely to have depressive symptoms compared with daily smokers. Among late adolescents, non-daily smokers had higher risks of depressive symptoms, suicide ideation, plan and attempt than never smokers, whereas the risk for suicide attempts was lower than daily smokers.

CONCLUSIONS

Our findings suggest that non-daily smoking in adolescents was associated with risks for depressive symptoms and suicidal behaviours, and the association was more prominent in early adolescents. Careful attention on the mental health of adolescent non-daily smokers is needed because this is an increasing and easily overlooked group.

Effectiveness of Fresh Start: A Randomized Study of a School-Based Program to Retain a Negative Attitude Toward Substance Use in Secondary School Freshmen

BACKGROUND

The transition to secondary school is linked to more positive attitudes toward substance use, which prelude the moment of first use. Fresh Start is a school-based prevention program for secondary school freshmen (12-13 years old) to retain negative attitudes.

OBJECTIVES

This study evaluates the effectiveness of Fresh Start on the attitudes toward smoking, alcohol use, and cannabis use, and on multiple secondary outcome measures. In addition, the effect of timing of the program within the schoolyear was examined.

METHODS

A cluster randomized trial was conducted. 48 classes, containing 1083 secondary school freshmen, were randomly allocated to the experimental or waiting list control condition. Experimental classes completed Fresh Start between October 2015 and January 2016 and waiting list control classes completed Fresh Start between March 2016 and May 2016. Measurements were scheduled at three points in time (September 2015, February 2016, and June 2016). Data were analyzed by means of multilevel analyses.

RESULTS

Fresh Start had small but significant effects on the attitudes toward smoking, alcohol use and cannabis use. The majority of secondary outcome measures were not influenced by Fresh Start, although a small, adverse effect was found on the perceived social acceptance of cannabis use by friends. Timing of the intervention within the schoolyear did not influence its effectiveness. Conclusions/Importance: Fresh Start can help to delay the development of positive attitudes toward substance use in secondary school freshmen. Strengths and limitations, implications for practice and suggestions for future research are discussed.

Smoking prevention in children and adolescents: A systematic review of individualized interventions

OBJECTIVE

This study systematically reviewed the literature to determine what type of cognitive-behavioral based interventions administered outside of formal school settings effectively prevent smoking initiation among children and adolescents.

METHODS

Applying the PRISMA guidelines we searched MEDLINE, PsycINFO, CINHAL, Pub Med, SCOPUS, and Sport Discus. Article review, data extraction, and assessment of risk of bias were conducted by two independent reviewers.

RESULTS

We included 16 studies administered in various settings: seven in health care; four informally during and outside of school hours; three in the home; and two in extra-curricular settings. Positive preventive effects in smoking behavior ranging from 3-months to 4-years were observed in eight studies. Social environmental influences (e.g., parental smoking, friends) are salient contributing factors.

CONCLUSIONS

Effective approaches involved interventions conducted in health care settings as well as those employing interpersonal communication and support strategies (e.g., via peer leaders, parent support, physicians).

PRACTICE IMPLICATIONS

Primary health care settings may be optimal for implementing cigarette smoking prevention interventions for children and adolescents. Providing tailored education and facilitating interpersonal discussions between health care providers and families about the risks of smoking/strategies to avoid uptake, as well as capitalizing on technology-based modalities may reduce rates among children and adolescents.

Relationships Between Smoking and Sleep Problems in Black and White Adolescents

Study Objectives

The relationship between sleeping and smoking during adolescence remains unclear and is likely complex. We aim to evaluate the longitudinal reciprocal associations between sleep problems, sleep duration, and smoking among non-Hispanic white (NHW) and non-Hispanic black (NHB) youth.

Design

Prospective cohort study.

Setting

NEXT Generation Health Study.

Participants

A national sample (N = 1394) of NHB and NHW 10th graders were surveyed annually between 2009 (Wave 1) and 2012 (Wave 3).

Interventions

N/A.

Measurements and Results

Past 30-day smoking, chronic difficulty falling asleep, recent difficulty falling asleep, difficulty staying asleep, and weekday and weekend sleep duration were measured at each wave. Using structural equation models, we observed significant autocorrelations over time for sleep problems and sleep duration. We found significant reciprocal, prospective relationships between smoking and sleep problems. The strengths of the relationships differed by race, with a stronger association between sleep problems and subsequent smoking for NHB than NHW youth. Conversely, a stronger association between smoking and subsequent sleep problems for NHW than NHB youth was observed. These association were independent of demographics, snoring or sleep apnea, body mass index, depressive symptoms, alcohol use, and soda consumption.

Conclusions

Reciprocal and prospective relationships exist for youth smoking and sleep problems and duration in both NHW and NHB youth. Further research is needed to unravel the complex relationship between the direct effects of nicotine, lifestyle choices that may link smoking and sleep problems, and racial differences.

Re-exposure to nicotine-associated context from adolescence enhances alcohol intake in adulthood

Alcohol and nicotine are the two most commonly-abused substances and are often used together. Nicotine enhances alcohol-drinking behaviors in humans and in animals, and was suggested to enhance the reinforcing properties of other reinforcers. Here, we show that nicotine-associated environment, rather than nicotine itself, enhances alcohol intake in rats. Adolescent rats received repeated intermittent injections of nicotine (0.4 mg/kg, i.p., 5 injections, every 3^rd day) or saline. The injection was paired with their home cage, or with the subsequent alcohol self-administration context. Rats were then trained to self-administer 20% alcohol. Nicotine given in the home cage did not alter subsequent alcohol intake. However, pairing nicotine with the operant chamber during adolescence led to a long-lasting increased alcohol self-administration in adulthood, compared to nicotine pre-treatment in other contexts. This effect persisted 3 months after nicotine cessation, in a relapse test after abstinence. Furthermore, re-exposure to the nicotine-associated context in adult rats led to a decrease in glial cell line-derived neurotrophic factor (Gdnf) mRNA expression in the ventral tegmental area, an effect that leads to increased alcohol consumption, as we have previously reported. Our findings suggest that retrieval of nicotine-associated contextual memories from adolescence may gate alcohol intake in adulthood, with a possible involvement of GDNF.

A school-based programme for tobacco and alcohol prevention in special education: effectiveness of the modified 'healthy school and drugs' intervention and moderation by school subtype

AIMS

To test the effectiveness of the Healthy School and Drugs (HSD) programme on tobacco and alcohol use in Dutch secondary special education (SE) schools, and whether this depends upon subtypes of SE schools and the level of implementation.

DESIGN

In a quasi-experimental design with baseline and post-treatment follow-up, 363 students were allocated arbitrarily or depending on teacher motivation to either intervention condition (n = 205) or usual curriculum (n = 158).

SETTING

Thirteen secondary SE schools spread throughout the Netherlands.

PARTICIPANTS

Participants were recruited during the autumn of 2013 from three school subtypes: SE for adolescents with intellectual/physical disabilities (SEI; n = 13), behavioural/emotional difficulties (SEB; n = 136) and learning disabilities/developmental disorders (SEL; n = 214).

MEASUREMENTS

Self-reported life-time smoking prevalence and life-time drinking frequency as outcomes, and school subtype (SEL/SEB) and implementation fidelity (high/low) as moderators.

FINDINGS

No significant differences were found at follow-up in life-time smoking [odds ratio (OR) = 1.52; 95% confidence interval (CI) = 0.74-3.12] and drinking frequency (d = 0.01; 95% CI = -0.16 to 0.18). Interaction analyses revealed adverse effects in SEB students for alcohol use (d = 0.43; 95% CI = 0.16-0.69). Effect on tobacco refusal self-efficacy was moderated positively by implementation fidelity (d = 0.35; 95% CI = 0.07-0.63).

CONCLUSION

The Healthy School and Drugs programme adapted for secondary special education in the Netherlands lacked clear evidence for effects on all outcomes. This pilot study suggests further that, within special education, substance use interventions may need to be targeted at school subtypes, as these may have harmful effects among students with behavioural difficulties. Finally, limited evidence was found that programme effectiveness may depend upon implementation fidelity.

Relationships Between Smoking and Sleep Problems in Black and White Adolescents

Study Objectives

The relationship between sleeping and smoking during adolescence remains unclear and is likely complex. We aim to evaluate the longitudinal reciprocal associations between sleep problems, sleep duration, and smoking among non-Hispanic white (NHW) and non-Hispanic black (NHB) youth.

Design

Prospective cohort study.

Setting

NEXT Generation Health Study.

Participants

A national sample (N = 1394) of NHB and NHW 10th graders were surveyed annually between 2009 (Wave 1) and 2012 (Wave 3).

Interventions

N/A.

Measurements and Results

Past 30-day smoking, chronic difficulty falling asleep, recent difficulty falling asleep, difficulty staying asleep, and weekday and weekend sleep duration were measured at each wave. Using structural equation models, we observed significant autocorrelations over time for sleep problems and sleep duration. We found significant reciprocal, prospective relationships between smoking and sleep problems. The strengths of the relationships differed by race, with a stronger association between sleep problems and subsequent smoking for NHB than NHW youth. Conversely, a stronger association between smoking and subsequent sleep problems for NHW than NHB youth was observed. These association were independent of demographics, snoring or sleep apnea, body mass index, depressive symptoms, alcohol use, and soda consumption.

Conclusions

Reciprocal and prospective relationships exist for youth smoking and sleep problems and duration in both NHW and NHB youth. Further research is needed to unravel the complex relationship between the direct effects of nicotine, lifestyle choices that may link smoking and sleep problems, and racial differences.

Factors associated with different smoking status in European adolescents: results of the SEYLE study

Early onset and long-term smoking are associated with physical and psychological health problems. The aim of the presented analysis was to investigate risk and influencing factors for different smoking status in a big sample of European adolescents. In the context of the "saving and empowering young lives in Europe" (SEYLE) study we surveyed 12,328 adolescents at the age of 13-17 from 11 countries. The survey took place in a school-based context using a questionnaire. Overall 58% reported the onset of ever-smoking under the age of 14 and 30.9% smoke on a daily basis. Multinomial logistic regression model showed significant positive associations between adolescent smoking and internalizing problems (suicidal behavior, direct self-injurious behavior, anxiety), externalizing problems (conduct problems, hyperactivity, substance consumption) and family problems (parental substance consumption, broken home). Our data show that smoking among adolescents is still a major public health problem and adolescents who smoke are at higher risk for mental problems. Further, adolescent smoking is associated with broken home families and parental behaviors. Therefore, early preventive measures are necessary not only for adolescents, but also for their parents.

Trajectories of Substance Use: Onset and Adverse Outcomes Among North American Indigenous Adolescents

North American Indigenous communities experience disproportionately high rates of substance use, abuse, and dependence and their accompanying consequences. This study uses group-based trajectory modeling of past-year substance use (alcohol, marijuana, and cigarettes) with a longitudinal sample of Indigenous adolescents from the northern Midwest and Canada (spanning ages 10-18 years). The early-onset trajectory (36.3%) had more adverse psychosocial difficulties at baseline than the mid-onset group (38.3%); both trajectories were associated with several negative outcomes at the end of the study. The late-onset trajectory (25.3%) did not initiate substance use until later adolescence and had far better outcomes at the last wave of the study. Timing of onset matters. Prevention efforts should begin in late childhood and continue through mid-adolescence.

Mechanisms and genetic factors underlying co-use of nicotine and alcohol or other drugs of abuse

Concurrent use of tobacco and alcohol or psychostimulants represents a major public health concern, with use of one substance influencing consumption of the other. Co-abuse of these drugs leads to substantial negative health outcomes, reduced cessation, and high economic costs, but the underlying mechanisms are poorly understood. Epidemiological data suggest that tobacco use during adolescence plays a particularly significant role. Adolescence is a sensitive period of development marked by major neurobiological maturation of brain regions critical for reward processing, learning and memory, and executive function. Nicotine exposure during this time produces a unique and long-lasting vulnerability to subsequent substance use, likely via actions at cholinergic, dopaminergic, and serotonergic systems. In this review, we discuss recent clinical and preclinical data examining the genetic factors and mechanisms underlying co-use of nicotine and alcohol or cocaine and amphetamines. We evaluate the critical role of nicotinic acetylcholine receptors throughout, and emphasize the dearth of preclinical studies assessing concurrent drug exposure. We stress important age and sex differences in drug responses, and highlight a brief, low-dose nicotine exposure paradigm that may better model early use of tobacco products. The escalating use of e-cigarettes among youth necessitates a closer look at the consequences of early adolescent nicotine exposure on subsequent alcohol and drug abuse.

A Role for Epigenetics in Broadening the Scope of Pediatric Care in the Prevention of Adolescent Smoking

Adolescence presents a critical opportunity to support the development of healthy patterns of behavior and prevent future health problems. Unfortunately, there is not yet a well-developed prevention model that allows pediatricians to initiate and monitor prevention efforts for the substantial minority of individuals who engage in risky behavior during adolescence. We suggest that recently developed epigenetic technologies may provide a bridge to a new prevention paradigm in which pediatricians screen for indicated smoking prevention services. Specifically, since currently available tobacco use screening measures are insensitive to low levels of use, newly developed methylation based approaches may enhance the sensitivity of the initial screening for nascent smoking behavior as well monitoring of outcomes. We conclude that the incorporation of Next Gen screening technologies into standard pediatric evaluations may allow for more effective referral to prevention programming for tobacco use. In addition to the potential direct impact on long-term enhancement of health outcomes secondary to smoking prevention, well-established links between smoking and other risk behaviors suggest that expanded referral for nascent smoking may also create opportunities to address other risky adolescent behaviors, and so decrease several interrelated drivers of long-term health care costs.

The role of tobacco outlet density in a smoking cessation intervention for urban youth

This study investigates the role of tobacco outlet density in a randomized controlled trial of a text messaging-based smoking cessation intervention conducted among a sample of 187 primarily African American youth in a midsize U.S. city. A moderated mediation model was used to test whether the indirect effect of residential tobacco outlet density on future smoking was mediated by the intention to smoke, and whether this indirect effect differed between adolescents who received the intervention and those who did not. Results indicated that tobacco outlet density is associated with intention to smoke, which predicts future smoking, and that the indirect effect of tobacco outlet density on future smoking is moderated by the intervention. Tobacco outlet density and the intervention can be viewed as competing forces on future smoking behavior, where higher tobacco outlet density acts to mitigate the sensitivity of an adolescent to the intervention's intended effect. Smoking cessation interventions applied to youth should consider tobacco outlet density as a contextual condition that can influence treatment outcomes.

Association Between Cumulative Psychosocial Risk and Cervical Human Papillomavirus Infection Among Female Adolescents in a Free Vaccination Program

OBJECTIVE

This study investigated the association of cervical human papillomavirus (HPV) infection with cumulative psychosocial risk reflecting family disadvantage, psychological distress, and unhealthy lifestyle.

METHODS

The sample (N = 745) comprised sexually active female adolescent patients (12-19 yr), primarily ethnic minorities, enrolled in a free HPV vaccination program. Subjects completed questionnaires and provided cervical swabs for HPV DNA testing. Unweighted and weighted principal component analyses for categorical data were used to derive multisystemic psychosocial risk indices using 9 indicators: low socioeconomic status, lack of adult involvement, not attending high school/college, history of treatment for depression/anxiety, antisocial/delinquent behavior, number of recent sexual partners, use of alcohol, use of drugs, and dependency risk for alcohol/drugs. The association between cervical HPV (any type, high-risk types, vaccine types) assayed by polymerase chain reaction and self-reported number of psychosocial risk indicators was estimated using multivariable logistic regression.

RESULTS

Subjects had a median of 3 psychosocial risk indicators. Multiple logistic regression analyses showed associations with unweighted and weighted number of psychosocial indicators for HPV any type (adjusted odds ratio [aOR] = 1.1; 95% confidence interval [CI], 1.0-1.2), with the strongest associations between weighted drug/alcohol use, drug/alcohol dependency risk, and antisocial/delinquent behavior and detection of HPV vaccine types (aOR = 1.5; 95% CI, 1.1-2.0) independent of number of recent sexual partners and vaccine dose (0-3).

CONCLUSION

Increased HPV infections including HPV vaccine types were associated with greater number of psychosocial risk indicators even after controlling for demographics, sexual behavior, history of chlamydia, and vaccine dose.

Nicotine and the adolescent brain

Adolescence encompasses a sensitive developmental period of enhanced clinical vulnerability to nicotine, tobacco, and e-cigarettes. While there are sociocultural influences, data at preclinical and clinical levels indicate that this adolescent sensitivity has strong neurobiological underpinnings. Although definitions of adolescence vary, the hallmark of this period is a profound reorganization of brain regions necessary for mature cognitive and executive function, working memory, reward processing, emotional regulation, and motivated behavior. Regulating critical facets of brain maturation are nicotinic acetylcholine receptors (nAChRs). However, perturbations of cholinergic systems during this time with nicotine, via tobacco or e-cigarettes, have unique consequences on adolescent development. In this review, we highlight recent clinical and preclinical data examining the adolescent brain's distinct neurobiology and unique sensitivity to nicotine. First, we discuss what defines adolescence before reviewing normative structural and neurochemical alterations that persist until early adulthood, with an emphasis on dopaminergic systems. We review how acute exposure to nicotine impacts brain development and how drug responses differ from those seen in adults. Finally, we discuss the persistent alterations in neuronal signaling and cognitive function that result from chronic nicotine exposure, while highlighting a low dose, semi-chronic exposure paradigm that may better model adolescent tobacco use. We argue that nicotine exposure, increasingly occurring as a result of e-cigarette use, may induce epigenetic changes that sensitize the brain to other drugs and prime it for future substance abuse.

Gender differences in age of smoking initiation and its association with health

BACKGROUND

It is generally accepted that smoking starts in adolescence and earlier initiation is associated with more negative health outcomes. Some research suggests that women initiate smoking at later ages and have more negative health outcomes than men. The purpose of this study was to examine gender differences in age of initiation and its association with health.

METHODS

The sample included men (n=8,506) and women (n=8,479) with a history of smoking from the 2001-2002 National Epidemiological Survey of Alcohol Related Conditions. Logistic regression was used to examine gender differences in the effect of late smoking initiation on physical and mental health status after adjusting for covariates.

RESULTS

At mostly all ages after 16, women exceeded men in rates of smoking initiation (59.8% vs. 50.3%, p<.001). Among late initiators (≥16), women were more likely than men to have hypertension (OR:1.24,CI:1.09-1.41), heart disease (OR:1.20,CI:1.00-1.45), major depressive disorder (OR:2.54,CI:2.22-2.92) and generalized anxiety disorder (OR:2.34,CI:1.84-2.99). Among early initiators (<16), women were more likely than men to have major depressive disorder (OR:2.42,CI:2.11-2.77) and generalized anxiety disorder (OR:2.01,CI:1.59-2.54) but there were no gender differences in the likelihood of having hypertension (OR:1.04,CI:0.89-1.22) and heart disease (OR:1.11,CI:0.90-1.36).

CONCLUSIONS

In late adolescence and adulthood, women exceed men in smoking initiation. Late initiation was associated with more significant physical health risks for women than men. Our findings raise questions about generally accepted notions on the age at which smoking initiation occurs and its association with health.

Development and Outcomes of a Text Messaging Tobacco Cessation Intervention With Urban Adolescents

BACKGROUND

This paper describes the development of an urban adolescent text messaging tobacco cessation intervention and preliminary findings from a randomized, controlled trial. The authors successfully adapted a face-to-face intervention into a personalized, automated, and interactive 5-day texting protocol.

METHODS

Respondent-driven sampling was used beginning at a community substance abuse facility. Seventy-two tobacco-dependent adolescents were randomized into an automated computer texting program that delivered either the experimental condition of 30 motivational interviewing- and social network counseling-based personalized messages or the attention control condition consisting of a texting program covering general (non-smoking-related) health habits. All teens were provided smartphones for the study and were assessed at baseline and at 1, 3, and 6 months post intervention. Analyses examined condition×time interactions.

RESULTS

At 6 months, the experimental condition decreased the number of cigarettes smoked in the past 30 days, increased intentions not to smoke in the future, and increased peer social support compared with controls. Effect sizes were moderate to large.

CONCLUSIONS

These findings are unique, as they target urban adolescents with a mobile health format and add to the growing literature on the efficacy of text-delivered interventions.

Predictors of substance use among vulnerable adolescents in five cities: findings from the well-being of adolescents in vulnerable environments study

PURPOSE

Adolescent substance use has numerous consequences. Our goals in this article are to compare the prevalence and correlates of substance use among ethnically diverse adolescents.

METHODS

Data were from 2,332 adolescents aged 15-19 years recruited via respondent-driven sampling from disadvantaged settings in five cities. Multivariate logistic regression was used to identify correlates of current substance use.

RESULTS

About half of the respondents were male. Most adolescents (73.4%) were currently enrolled in school and identified a father (86.2%) and mother (98.6%) figure and strong peer support. Sixty-two percent reported lifetime use of at least one substance. Overall, the most common substances ever used were alcohol (44.6%), cigarettes (26.2%), and marijuana (17.9%). Mean age at first use of alcohol was 14.2 ± 3.1 years. Current alcohol use was highest in Johannesburg (47.4%) and lowest in Delhi (2.1%). The mean age at first use of cigarettes was 14.4 ± 2.8 years. Current cigarette smoking was highest in Johannesburg (32.5%) and lowest in Delhi (3.7%). Male gender predicted current alcohol use in all sites, older age (17-19 years) was also a predictor in Baltimore. Male gender (Johannesburg and Shanghai), older age (Baltimore and Shanghai), and being out of school (Baltimore, Johannesburg, and Shanghai) predicted current cigarette smoking. Absence of a caring father figure was predictive for current alcohol use in Baltimore and Shanghai. Stronger peer support predicted alcohol (Johannesburg and Shanghai) and cigarette use (Johannesburg).

CONCLUSIONS

Substance use is still a major issue among adolescents around the world, underscoring the need for continued research and interventions.

Illicit drug use among school-going adolescents in Malaysia

Illicit drug use among adolescents has become a public health issue in Malaysia. This study was from the Global School-Based Student Health Survey (GSHS) and aimed to determine the prevalence of and factors associated with illicit drug use among school-going adolescents in Malaysia. A 2-stage stratified cluster sampling method was used and data were collected via a self-administered questionnaire. A total of 25 507 students participated in the study. The prevalence of adolescents who ever used illicit drugs was 1.7%. Adolescents who ever used illicit drugs were associated with current smoking (adjusted odds ratio [aOR] = 6.99; 95% CI = 5.19, 9.40), current alcohol use (aOR = 4.63; 95% CI = 3.43, 6.26), ever having sex (aOR = 4.76; 95% CI = 3.54, 6.41), truancy (aOR = 1.43; 95% CI = 1.07, 1.90), lack of peer support (aOR = 1.47; 95% CI = 1.07, 2.03), and lack of parental monitoring (aOR = 1.71; 95% CI = 1.22, 2.39). Public health intervention should be addressed to prevent illicit drug used among adolescents.

Problematic substance use among Hispanic adolescents and young adults: implications for prevention efforts

Using data collected between 2005 and 2012 from a longitudinal study of acculturation patterns and substance use among Hispanic youth in Southern California (N = 2722), we fit multivariate logistic regression models to estimate the association of type and frequency of drug use, friend and parent drug use, cultural orientation (measured by the ARSMA-II), and psychological distress (CES-D score) in 10th grade with problematic substance use (measured with the RAPI) in (i) 11th grade and (ii) young adulthood. We conclude that future intervention efforts with Hispanic adolescents and young adults should target polysubstance and problem users and emphasize inter-individual, structural, and cultural processes as they relate to problematic substance use.

Age-dependent alterations in reward-seeking behavior after brief nicotine exposure

RATIONALE

Adolescence is a developmental period that coincides with the onset of tobacco use. Teen smokers are also more likely to abuse other drugs compared to nonsmokers. Previous studies with rats have shown that low-dose nicotine pretreatment enhances initial acquisition of cocaine self-administration when given during early adolescence, but not at later ages. The aim of the present study was to determine whether these nicotine pretreatment effects extend to extinction and reinstatement of reward-seeking behavior.

METHODS

Adolescent [postnatal day (P)28] and adult rats (P86) were pretreated for 4 days with nicotine (60 μg/kg, i.v.) or saline. Following pretreatment, rats were allowed to nose poke for cocaine (500 μg/kg/infusion) or sucrose pellets for at least 12 days or until meeting acquisition criterion. Responding was then extinguished for at least 7 days or until extinction criterion was met. The following day, the rats were reinstated with either a priming injection of cocaine (10 mg/kg, i.p.) or sucrose pellets.

RESULTS

Nicotine markedly enhanced extinction of cocaine self-administration in adolescent rats, but not adults. Pretreatment also enhanced the acquisition of cocaine self-administration in adolescents, while reducing discrimination for the reinforced hole in adults. There were no pretreatment or age effects on cocaine-induced reinstatement. In contrast, nicotine induced only minor enhancement of sucrose-taking behavior in adolescents, with no significant impact on extinction or reinstatement at either age.

CONCLUSIONS

Nicotine pretreatment affects reward-related behavior in both an age- and reward-dependent manner. These findings show that brief nicotine exposure during early adolescence enhances drug-related learning.

Gender differences in risk behaviors among high school youth

The US Centers for Disease Control and Prevention's (CDC) Youth Risk Behavior Surveillance System (YRBSS) demonstrates that American youth engage in a wide variety of risky behaviors.¹ The frequency and type of these behaviors often differ by a number of factors, such as socioeconomic status, race, and ethnicity. For example, results of the 2011 YRBSS revealed that white high school students were most likely to have texted or e-mailed while driving or been bullied on school property, while black high school students were most likely to have engaged in risky sexual behaviors, to have been physically inactive, and to be obese.¹ Conversely, Hispanic high school students were most likely to have ridden with a driver who had been drinking alcohol; to have ever used cocaine, inhalants, or ecstasy; and to have failed to use protection to prevent pregnancy during last sexual intercourse.¹ However, it is difficult to discern whether differences in risk-taking behaviors between and among ethnic groups can actually be attributed to differences in group norms, socioeconomic status, or cultural beliefs regarding acceptance or rejection of such behaviors,¹ suggesting a need for more comprehensive regional investigations.

Effects of adolescent nicotine exposure and withdrawal on intravenous cocaine self-administration during adulthood in male C57BL/6J mice

Studies of adolescent drug use show (1) a pattern in which the use of tobacco precedes the use of other drugs and (2) a positive relationship between adolescent tobacco use and later drug use. These observations have led to the hypothesis that a causal relationship exists between early exposure to nicotine and the later use of hard drugs such as cocaine. Using male C57BL/6J mice, we tested the hypothesis that nicotine exposure in adolescence leads to increased intravenous self-administration (IVSA) of cocaine in adulthood. Using miniature osmotic pumps, we exposed mice and their littermate controls to nicotine (24 mg/kg/day) or vehicle, respectively, over the entire course of adolescence [postnatal days (P) 28-56]. Nicotine exposure was terminated on P56 and mice were not exposed to nicotine again during the experiment. On P73, mice were allowed to acquire cocaine IVSA (1.0 mg/kg/infusion) and a dose-response curve was generated (0.18, 0.32, 0.56, 1.0, 1.8 mg/kg/infusion). Lever pressing during extinction conditions was also evaluated. All mice rapidly learned to lever press for the combination of cocaine infusions and non-drug stimuli. Analysis of the dose-response curve revealed that adolescent nicotine-exposed mice self-administered significantly more (P < 0.05) cocaine than controls at all but the highest dose. No significant differences were observed between adolescent nicotine-exposed and control mice during the acquisition or extinction stages. These results indicate that adolescent nicotine exposure can increase cocaine IVSA in mice, which suggests the possibility of a causal link between adolescent tobacco use and later cocaine use in humans.

Nicotine modulation of adolescent dopamine receptor signaling and hypothalamic peptide response

Adolescence is a sensitive developmental period for limbic and dopamine systems that coincides with the typical age for onset of tobacco use. We have previously shown that a 4-day, low-dose nicotine (0.06 mg/kg) pretreatment enhances locomotor and penile response to the D2-like agonist, quinpirole (0.4 mg/kg), in adolescent but not adult rats. The present study is designed to determine mechanisms underlying this effect. Nicotine enhancement of adolescent quinpirole-induced locomotion was mediated by D2 receptors (D2Rs) since it was blocked by the D2R antagonist, L-741,626, but not by the D3R and D4R antagonists, NGB 2904 and L-745,870. Enhancement of quinpirole-induced erectile response was blocked by both L-741,626 and NGB 2904, indicating involvement of D3Rs. Whereas D2R binding was unaffected by adolescent nicotine pretreatment, effector coupling in the striatum was increased, as determined by GTPγS binding. Nicotine pretreatment enhanced quinpirole-induced c-fos mRNA expression in the hypothalamic paraventricular and supraoptic nuclei in adolescents only. Adolescent nicotine pretreatment enhanced c-fos mRNA expression in corticotropin releasing factor (CRF) cells of the paraventricular nucleus, and enhancement of penile erection was blocked by the CRF-1 receptor antagonist, CP 376,396. These findings suggest that adolescent dopamine and CRF systems are vulnerable to alteration by nicotine. This is the first evidence for a role of CRF in adolescent erectile response.

Early childhood predictors of early onset of smoking: a birth prospective study

OBJECTIVE

Early onset of smoking is associated with subsequent abuse of other substances and development of negative health outcomes. This study aimed to examine early life predictors of onset of smoking in an Australian young cohort.

METHODS

Data were from the Mater Hospital and University of Queensland Study of Pregnancy (MUSP), a population-based prospective birth cohort study (1981-2012). The present study is based on a cohort of 3714 young adults who self-reported smoking status and age of onset of smoking at the 21-year follow-up. Of these, data were available for 3039 on early childhood factors collected between the baseline and 14-year follow-up of the study.

RESULTS

Of 3714 young adults, 49.6% (49.9% males and 49.3% females) reported having ever smoked cigarettes. For those who had ever smoked, mean and median ages at first smoke were 15.5 and 16.0years, respectively. In multivariate Cox proportional hazard analysis mother's education, change in maternal marital status, maternal cigarette smoking and alcohol consumption, maternal depression and child externalizing when the child was 5years statistically significantly predicted early onset of smoking.

CONCLUSIONS

The data suggest that individuals exposed to personal and environmental risk factors during the early stage of childhood are at increased risk of initiation to cigarette smoking at an earlier age. Identification of the pathways of association between these early life factors and initiation to cigarette smoking may help reduce risk of tobacco smoking in adolescents and its adverse consequences.

Initial Smoking Experiences and Current Smoking Behaviors and Perceptions among Current Smokers

Purpose. We examine early-onset cigarette smoking and how, if at all, it is related to subsequent smoking practices. Methods. From 2004 to 2007, face-to-face interviews were conducted with 485 adult cigarette smokers residing in the Atlanta metropolitan area. Data analysis involved a multivariate analysis to determine whether age of smoking onset was related to current smoking practices when the effects of gender, age, race, marital/relationship status, income, and educational attainment were taken into account. Results. The mean age for smoking onset was 14.8, and more than one-half of all smokers had their first cigarette between the ages of 12 and 16. Most people reported an interval of less than one month between their first and second time using tobacco. Earlier onset cigarette smoking was related to more cigarette use and worse tobacco-related health outcomes in adulthood. Conclusions. Early prevention and intervention are needed to avoid early-onset smoking behaviors. Intervening after initial experimentation but before patterned smoking practices are established will be challenging, as the interval between initial and subsequent use tends to be short.

Risk factors of future smoking among Thai youth: a secondary analysis of the Thai Global Youth Tobacco Survey

The study aimed to identify the risk factors for future smoking among Thai youth aged 13 to 15 years (seventh to ninth grade). Data from the nationally representative 2005 Thai Global Youth Tobacco Survey (n = 15 774) were analyzed using descriptive statistics and logistic regression. Among nonsmoking Thai youth, boys were much more likely to have intention of future smoking (odds ratio [OR] = 0.56, 95% confidence interval [CI] = 0.37-0.84). Younger youth were more likely to be cigarette smokers in the future (OR = 0.70, 95% CI = 0.56-0.88). Youth having the intention of smoking from a friend's cigarette offer were 5.29 times more likely to have intention of future smoking, compared with those who did not (95% CI = 3.75-7.46). Understanding and targeting youth at higher risk for future smoking can provide for a lowering of the youth smoking rate in Thailand and contribute to the country's continued efforts in effective youth tobacco control.

Gender differences in early alcohol and tobacco use as a risk factor in Spanish adolescents

The sample is made up of 1,190 adolescents (52.8% boys; mean age = 16.81) from 37 random schools in the urban and rural areas of Asturias (northern Spain). The survey was conducted in 2008, assessing the use and patterns of use of alcohol and other drugs, age at onset of use, and psychosocial consequences. Items from the ESPAD and FRIDA questionnaires were employed. Univariate analyses and binary logistic regression analyses were carried out to determine the different predictive value for boys and girls of early-onset alcohol and tobacco use. The study's limitations and implications are noted.

[Teenage and adult pregnancy: different correlations between socio-economic status and smoking]

INTRODUCTION

Smoking occurs frequently during pregnancy, thereby putting mother and child at health risks. Low socio-economic status is a risk factor for smoking.

AIM

To investigate the relationship between smoking and low income in teenage and adult pregnancy, which is an important measure of poor socioeconomic status.

METHOD

The authors used subject-level data from the US NSDUH database, which contains information on pregnancies and smoking.

RESULTS

Teenage pregnancy is associated with higher, whereas adult pregnancy with lower prevalence of smoking, compared to the age-matched female population. The association between income and smoking is age-dependent. Among adults there is an inverse relationship (high income -- low-risk of smoking), while in teenage pregnancy smoking increases with income.

CONCLUSIONS

To investigate in teenage and adult pregnancy the relationship between smoking and low income, which is an important measure of poor socio-economic status. Higher socioeconomic status may be associated with risky behaviour, thereby increasing both the risk of smoking and early pregnancy.

Cigarette smoking as a risk factor for other substance misuse: 10-year study of individuals with and without attention-deficit hyperactivity disorder

BACKGROUND

We previously documented that cigarette smoking is a risk factor for subsequent alcohol and drug misuse and dependence in adolescent girls with attention-deficit hyperactivity disorder (ADHD).

AIMS

To revisit this hypothesis with a large longitudinal sample of both genders followed up for 10 years into young adulthood.

METHOD

We used data from two identically designed, longitudinal, case-control family studies of boys and girls with and without ADHD ascertained from psychiatric and paediatric sources. We studied 165 individuals with ADHD and 374 controls followed up longitudinally and masked for 10 years. We assessed ADHD, smoking and substance use status using structured diagnostic interviews. We tested the association between cigarette smoking and subsequent substance use outcomes using Cox proportional hazard regression models.

RESULTS

Youth with ADHD who smoked cigarettes (n = 27) were significantly more likely to subsequently develop drug misuse and dependence compared with youth with ADHD who did not smoke (n = 138, P<0.05).

CONCLUSIONS

These results confirm that cigarette smoking increases the risk for subsequent drug and alcohol use disorders among individuals with ADHD. These findings have important public health implications, and underscore the already pressing need to prevent smoking in children with ADHD.

Prevalence and correlates of substance use among school children in six African countries

An increasing trend of noncommunicable diseases is a worldwide phenomenon, also including the developing countries. Few studies focus on adolescents' substance use in relation to mental distress and protective factors in African countries. The purpose of this study was to assess the prevalence and correlates (mental distress and protective factors) of substance use among school-going adolescents in six African countries. The sample included 20,765 students aged from 13 to 15 years from six African countries (Kenya, Namibia, Swaziland, Uganda, Zambia, Zimbabwe), chosen by a two-stage cluster sample design to represent all students in grades 6, 7, 8, 9, and 10 in each country. The measure used was part of the Global School-Based Health Survey (GSHS) questionnaire, including various domains of health behaviour. Results indicate a prevalence of 12.6% tobacco use (past month), 6.6% risky alcohol use (two or more per day for at least 20 days or more in the past month), and 10.5% of illicit drug use (three or more times ever) in school-going adolescents in six African countries. School truancy, loneliness, sleeping problems, sadness, suicidal ideation, suicide plans, and poverty were associated with substance use (tobacco, alcohol, illicit drugs), while school attendance and parental supervision and connectedness were protective factors for substance use, and peer support protective for tobacco use. It is concluded that tobacco use, risky drinking and illicit drug use were common, clustered together and were associated with school truancy, mental distress, and lack of parental and peer support among adolescent African school children. These findings stress the need for early and integrated prevention programmes.