Trends in U.S. Depression Prevalence From 2015 to 2020: The Widening Treatment Gap.

INTRODUCTION: Major depression is a common and potentially lethal condition. Early data suggest that the population-level burden of depression has been exacerbated by the COVID-19 pandemic. Prepandemic estimates of depression prevalence are required to quantify and comprehensively address the pandemic's impact on mental health in the U.S. METHODS: Data were drawn from the 2015-2020 National Survey on Drug Use and Health, a nationally representative study of U.S. individuals aged ≥12 years. The prevalence of past-year depression and help seeking for depression were estimated from 2015 to 2019, and time trends were tested with Poisson regression with robust SEs. Point estimates were calculated for 2020 and not included in statistical trend analyses because of differences in data collection procedures. RESULTS: In 2020, 9.2% (SE=0.31) of Americans aged ≥12 years experienced a past-year major depressive episode. Depression was more common among young adults aged 18-25 years (17.2%, SE=0.78), followed closely by adolescents aged 12-17 years (16.9%, SE=0.84). Depression increased most rapidly among adolescents and young adults and increased among nearly all sex, racial/ethnic, income, and education groups. Depression prevalence did not change among adults aged ≥35 years, and the prevalence of help seeking remained consistently low across the study period. CONCLUSIONS: From 2015 to 2019, there were widespread increases in depression without commensurate increases in treatment, and in 2020, past 12‒month depression was prevalent among nearly 1 in 10 Americans and almost 1 in 5 adolescents and young adults. Decisive action involving a multipronged public health campaign that includes evidence-based prevention and intervention to address this ongoing mental health crisis is urgently needed.

Alcohol Use Disorder Symptoms Rather than Alcohol Exposure Predict Experiences of Cannabis Use Disorder Symptoms among Adolescents and Young Adults.

Background: Alcohol and cannabis use are highly comorbid. Objective: We evaluate if alcohol use and/or alcohol use disorder symptoms predict experiences of cannabis use disorder symptoms among adolescents and young adults and whether the relationships differ based on frequency of cannabis use, recency of cannabis initiation and age. Method: Data were drawn from five annual surveys of the National Survey on Drug Use and Health (2014-2018) to include adolescents and young adults (age 12 to 21 years) who reported using cannabis and alcohol at least once in the past 30 days. Results: Number of alcohol use disorder symptoms, over and above alcohol quantity or frequency, was positively associated with each of the cannabis use disorder symptoms as well as the total number of cannabis use disorder symptoms endorsed. The association between alcohol and cannabis use disorder symptoms was stronger among those who were younger and those who initiated cannabis use within the past 2 years. Conclusions: Treatment should consider these and other cross-over effects of substance disorder symptoms when addressing risk for chronic and dependent use.

Behavioral symptoms of eating disorders among adopted adolescents and young adults in the United States: Findings from the Add Health survey.

OBJECTIVE: More adopted individuals report experiencing general psychopathology, poor parental attachment, and early childhood eating difficulties than nonadopted individuals, yet little is known about disordered eating in this population. This study sought to describe the relationship between adoption status and behavioral eating-disorder (ED) symptoms, and to examine potential correlates of ED symptoms that are unique to adopted individuals. METHOD: We examined data from adolescents and young adults from Waves 1 (n adopted = 561, nonadopted = 20,184), 2 (n adopted = 211, nonadopted = 14,525), and 3 (n adopted = 416, nonadopted = 14,754) of the National Longitudinal Study of Adolescent to Adult Health. ED symptom items included dieting, breakfast skipping, binge eating, extreme weight loss behaviors (EWLBs; i.e., self-induced vomiting, laxative use, diet pill use) and lifetime ED diagnosis. RESULTS: Compared to nonadopted individuals, adopted individuals were more likely to report EWLBs at Wave 2 and binge eating and lifetime ED diagnosis at Wave 3 (ps < .05). Among adopted individuals, contact with a biological parent was associated with higher rates of binge eating and lifetime ED diagnosis at Wave 3 (ps < .05), whereas age at adoption and having ever been in foster care were not associated with rates of ED symptoms. DISCUSSION: This study provides preliminary evidence that being adopted may be a risk factor for certain behavioral symptoms of EDs. Given the benefits of early detection and treatment of ED symptoms, mental health professionals working with adopted individuals should assess for disordered eating.

The Interpretation of Statistical Power after the Data have been Gathered.

Post-hoc power estimates (power calculated for hypothesis tests after performing them) are sometimes requested by reviewers in an attempt to promote more rigorous designs. However, they should never be requested or reported because they have been shown to be logically invalid and practically misleading. We review the problems associated with post-hoc power, particularly the fact that the resulting calculated power is a monotone function of the p-value and therefore contains no additional helpful information. We then discuss some situations that seem at first to call for post-hoc power analysis, such as attempts to decide on the practical implications of a null finding, or attempts to determine whether the sample size of a secondary data analysis is adequate for a proposed analysis, and consider possible approaches to achieving these goals. We make recommendations for practice in situations in which clear recommendations can be made, and point out other situations where further methodological research and discussion are required.

Socioeconomic Disparities in Smoking Among U.S. Adults With Depression, 2005-2014.

INTRODUCTION: The purpose of this study is to estimate changes in the cigarette smoking prevalence among U.S. adults with and without depression from 2005 to 2014 by income and education level and overall. METHODS: This study examined data from adult respondents (aged ≥18 years) in the National Survey on Drug Use and Health, an annual cross-sectional study of U.S. individuals. Data from the years 2005 to 2014 were analyzed for a total analytic sample of n=378,733. The prevalence of past-month cigarette smoking was examined annually from 2005 to 2014 among adults with and without past-year major depression, overall and by income/education, using linear trend analyses. Data analysis occurred in 2017. RESULTS: The prevalence of smoking declined significantly from 2005 to 2014 among those with depression (37.62% to 34.01%; p<0.001) and without depression (23.99% to 19.87%; p<0.001). Yet, smoking remained nearly twice as common among those with depression during this period. Among adults with depression in the lowest income and education groups, the prevalence of smoking was more than double the prevalence of smoking among adults with depression in the highest income and education groups. CONCLUSIONS: Disparities in smoking prevalence are pronounced when depression and SES are considered simultaneously. Targeted public health and clinical efforts to reduce smoking among adult smokers of lower SES with depression are needed.

Integrative Data Analysis of Gender and Ethnic Measurement Invariance in Nicotine Dependence Symptoms.

Little research has evaluated whether conflicting evidence for gender and racial/ethnic differences in nicotine dependence (ND) may be attributed to differences in psychometric properties of ND symptoms, particularly for young Hispanic smokers. Inadequate racial/ethnic diversity and limited smoking exposure variability has hampered research in young smokers. We used integrative data analysis (IDA) to pool DSM-IV ND symptom data for current smokers aged 12-25 (N = 20,328) from three nationally representative surveys (1999, 2000 National Surveys on Drug Use and Health (NSDUH) and Wave 1 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). Moderated nonlinear factor analysis (MNLFA) tested symptom measurement invariance in the pooled sample containing greater ethnic and smoking exposure variability. There was study noninvariance for most symptoms. NESARC participants were more likely to report tolerance, using larger amounts or for longer periods, inability to cut down/quit, and more time spent smoking at higher levels of ND severity, but reported emotional/physical health problems at lower ND severity. Four symptoms showed gender or race/ethnicity noninvariance, but observed differences were small. An ND severity factor score adjusting for symptom noninvariance related to study membership, gender, and race/ethnicity did not differ substantively from traditional DSM-IV diagnosis and number of endorsed symptoms in estimated gender and race/ethnicity differences in ND. Results were consistent with studies finding minimal gender and racial/ethnic differences in ND, and suggest that symptom noninvariance is not a major contributor to observed differences. Results support IDA as a potentially promising approach for testing novel ND hypotheses not possible in independent studies.

Progression of nicotine dependence, mood level, and mood variability in adolescent smokers.

Mood processes are theorized to play a role in the initiation and progression of smoking behavior. Available work using real-time assessments in samples of young smokers, including several reports from the Social and Emotional Contexts of Adolescent Smoking Patterns (SECASP) study, has indicated that smoking events acutely improve mood and that escalating smoking frequency may stabilize mood. However, prior analyses have not specifically evaluated within-person change in nicotine dependence, which is conceptually distinguishable from frequent smoking and may be associated with unique mood consequences. The current investigation addressed this question using data from 329 adolescent SECASP participants (9th or 10th grade at recruitment) who contributed mood reports via ecological momentary assessment in up to four 1-week bursts over the course of 24 months. Mixed-effects location scale analyses revealed that within-person increases in scores on the Nicotine Dependence Syndrome Scale were associated with elevations in negative mood level and increased variability of both positive and negative moods. These effects remained when within-person changes in smoking frequency were covaried and were not fully attributable to a subgroup of youth who rapidly escalated their smoking frequency over time. The findings indicate that adolescents tend to show increasing levels of positive mood states, decreasing levels of negative mood, and diminishing mood variability between ages 16 to 18, but progression of nicotine dependence may counteract some of these developmental gains. Emergence of withdrawal symptoms is a likely explanation for the adverse mood effects associated with dependence progression. (PsycINFO Database Record

Exploring alternate processes contributing to the association between maternal smoking and the smoking behavior among young adult offspring.

INTRODUCTION: Maternal smoking during pregnancy (MSP) is a known risk factor for regular smoking in young adulthood and may pose a risk independently of mother's lifetime smoking. The processes through which MSP exerts this influence are unknown but may occur through greater smoking quantity and frequency following initiation early in adolescence or increased sensitivity to nicotine dependence (ND) at low levels of smoking. METHODS: This study used path analysis to investigate adolescent smoking quantity, smoking frequency, and ND as potential simultaneous mediating pathways through which MSP and mother's lifetime smoking (whether she has ever smoked) increase the risk of smoking in young adulthood among experimenters (at baseline, <100 cigarettes/lifetime) and current smokers (>100 cigarettes/lifetime). RESULTS: For experimenters, MSP was directly associated with more frequent young adult smoking and was not mediated by adolescent smoking behavior or ND. Independently of MSP, the effect of mother's lifetime smoking was fully mediated through frequent smoking and was heightened ND during adolescence. Controlling for MSP eliminated a previously observed direct association between mother's lifetime smoking and future smoking among experimenters. For current smokers, only prior smoking behavior was associated with future smoking frequency. CONCLUSIONS: These results seem to rule out sensitivity to ND and increased smoking behavior as contributing pathways of MSP. Further, the impact of MSP on young adult smoking extends beyond that of having an ever-smoking mother. Future work should test other possible mediators; for example, MSP-related epigenetic changes or gene variants influencing the brain's nicotine response.

Time-varying effects of smoking quantity and nicotine dependence on adolescent smoking regularity.

BACKGROUND: Little is known about time-varying effects of smoking quantity and nicotine dependence on the regularity of adolescent smoking behavior. METHODS: The sample was drawn from the Social and Emotional Contexts of Adolescent Smoking Patterns Study which followed adolescent smokers over 5 assessment waves spanning 48 months. Participants included former experimenters (smoked <100 cigarettes/lifetime but did not smoke in past 90 days), recent experimenters (smoked <100 cigarettes/lifetime and smoked in past 90 days), and current smokers (smoked >100 cigarettes/lifetime and smoked in past 30 days). Mixed-effects regression models were run to examine the time-varying effects of smoking quantity and nicotine dependence on regularity of smoking behavior, as measured by number of days smoked. RESULTS: Smoking quantity and nicotine dependence were each found to be significantly associated with regularity of adolescent smoking and the size of each effect exhibited significant variation over time. The effect of smoking quantity decreased across time for each smoking group, while the effect of nicotine dependence increased across time for former and recent experimenters. By the 48-month follow-up, the effects of smoking quantity and nicotine dependence had each stabilized across groups. CONCLUSIONS: This study reveals that smoking quantity and nicotine dependence are not static risk factors for the development of more regular smoking patterns. At low levels of smoking when nicotine dependence symptoms are less common, smoking quantity is a stronger predictor of increased regularity of smoking, while for more experienced smokers, nicotine dependence predicts further increases in regularity.

An integrated data analysis approach to investigating measurement equivalence of DSM nicotine dependence symptoms.

INTRODUCTION: Research identifying nicotine dependence (ND) symptoms most appropriate for measurement of adolescent ND and invariant across the range of smoking exposure is hampered by limited sample size and variability of smoking behavior within independent studies. Integrative data analysis, the process of pooling and analyzing data from multiple studies, produces larger and more heterogeneous samples with which to evaluate measurement equivalence across the full continuum of smoking quantity and frequency. METHODS: Data from two studies were pooled to obtain a large sample of adolescent and young adult smokers with considerable variability in smoking. We used moderated nonlinear factor analysis, which produces study equivalent ND scores, to simultaneously evaluate whether 14 DSM ND symptoms had equivalent psychometric properties (1) at different levels of smoking frequency and (2) across a continuous range of smoking quantity, after accounting for study differences. RESULTS: Nine of 14 symptoms were equivalent across levels of smoking frequency and quantity in probability of endorsement at different levels of ND and in ability to discriminate between levels of ND severity. A more precise ND factor score accounted for study and smoking related differences in symptom psychometric properties. CONCLUSIONS: DSM-IV symptoms may be used to reliably assess ND in young populations across a wide range of smoking quantity and frequency and within both nationally representative and geographically restricted samples with different study designs. Symptoms shared across studies produced an equivalently scaled ND factor score, demonstrating that integrating data for the purpose of studying ND in young smokers is viable.

Adolescent nicotine dependence symptom profiles and risk for future daily smoking.

Recent research on adolescent smokers suggests that there are important differences in the types of nicotine dependence (ND) symptoms that emerge and different patterns of ND symptoms. The purpose of this study was to use data from the longitudinal Social and Emotional Contexts of Adolescent Smoking Patterns Study to identify latent subgroups of adolescent experimental and nondaily smokers varying in number and types of endorsed ND symptoms. Profiles were identified using baseline level of smoking, individual patterns of ND symptoms and other ND risk factors. Discrete time survival analysis was used to examine profile differences in probability of becoming daily smokers 48 months later. Four distinct subgroups of smokers with different patterns of smoking behavior, ND symptoms, and alcohol and other substance use emerged. Heavier smoking adolescents with high symptom endorsement, particularly the need to smoke in the morning, were most likely to become daily smokers 48 months later. A subgroup of social smokers had high smoking exposure and symptom endorsement (except need to smoke in the morning), and high levels of other substance use. Despite lower rates of smoking frequency and quantity compared to the heavier smoking class, 36% of these adolescents smoked daily by 48 months, with a steeper decline in survival rates compared to other lighter smoking classes. Morning smoking symptoms and symptoms prioritizing smoking (i.e., choosing to spend money on cigarettes instead of lunch or smoking when ill or where smoking is forbidden) might quickly identify adolescent non-daily smokers with more severe dependence and higher risk for daily smoking. A focus on skills for avoiding social situations involving use of alcohol and other drugs and reducing peer smoking influences may be an important focus for reducing smoking and other substance use among social smokers.

A Practical Guide to Calculating Cohen's f(2), a Measure of Local Effect Size, from PROC MIXED.

Reporting effect sizes in scientific articles is increasingly widespread and encouraged by journals; however, choosing an effect size for analyses such as mixed-effects regression modeling and hierarchical linear modeling can be difficult. One relatively uncommon, but very informative, standardized measure of effect size is Cohen's f(2), which allows an evaluation of local effect size, i.e., one variable's effect size within the context of a multivariate regression model. Unfortunately, this measure is often not readily accessible from commonly used software for repeated-measures or hierarchical data analysis. In this guide, we illustrate how to extract Cohen's f(2) for two variables within a mixed-effects regression model using PROC MIXED in SAS(®) software. Two examples of calculating Cohen's f(2) for different research questions are shown, using data from a longitudinal cohort study of smoking development in adolescents. This tutorial is designed to facilitate the calculation and reporting of effect sizes for single variables within mixed-effects multiple regression models, and is relevant for analyses of repeated-measures or hierarchical/multilevel data that are common in experimental psychology, observational research, and clinical or intervention studies.

The natural course of nicotine dependence symptoms among adolescent smokers.

INTRODUCTION: Few studies have investigated the natural course of nicotine dependence prospectively from the earliest experiences with smoking. METHODS: Drawing on a cohort of 9th- and 10th-grade adolescents followed over 48 months, survival analyses were conducted to evaluate the cumulative probability, following smoking initiation, for the development of nicotine dependence symptoms. RESULTS: Although each nicotine dependence symptom was significantly more prevalent among adolescents who had smoked more than 100 cigarettes by the end of the follow-up assessment, 20% of adolescents smoking fewer than 100 cigarettes reported experiencing "smoking to relieve restlessness and irritability" and "smoking a lot more now to be satisfied compared to when first smoked." Nicotine dependence symptoms were also reported before reaching 100 cigarettes for a substantial number of adolescents (between 9.4% and 58.8% for individual symptoms). Endorsement of nicotine dependence symptoms prospectively predicted past-week smoking (odds ratios [ORs] between 3.18 and 14.62 for significant symptoms) and past-month daily smoking (significant symptoms' ORs between 3.52 and 10.68) at the 48-month assessment even when controlling for amount of previous smoking. CONCLUSIONS: The present study adds to the growing body of literature on the natural course of nicotine dependence from earliest experiences with smoking by showing that symptoms of nicotine dependence may develop soon after initiation and/or at low levels of smoking. Our findings suggest that novice adolescent smokers should not be neglected in smoking cessation intervention and that screening and effective intervention for early emerging symptoms among adolescent smokers may be an important target in preventing chronic smoking.

Risk factors for adolescent smoking: parental smoking and the mediating role of nicotine dependence.

BACKGROUND: Parental smoking and early-emerging nicotine dependence symptoms are well-documented risk factors for adolescent smoking. However, very little is known about the mediating pathways through which these risk factors may act, or whether parental smoking may cause or signal early-emerging nicotine dependence symptoms. METHODS: Data were drawn from the longitudinal Social and Emotional Contexts of Adolescent Smoking Patterns Study. Adolescents who had smoked under 100 cigarettes in their lifetime (n=594; low-exposure group) and adolescents who had smoked over 100 cigarettes, but fewer than 5 cigarettes per day (n=152) were included in the analyses. Path analysis was performed on longitudinal data to investigate the association between parental smoking and smoking frequency at the 48 months follow-up, both directly and through mediating variables of smoking frequency, smoking quantity, and nicotine dependence. RESULTS: Father's smoking was associated with higher adolescent nicotine dependence scores at the baseline assessment wave. Structural equation modeling revealed that mother's smoking at baseline was associated with adolescent's smoking frequency at the 48-month follow-up, and its effect was partially mediated by both smoking frequency and nicotine dependence among low-exposure adolescent smokers. CONCLUSIONS: Parental smoking is a risk factor for future smoking in low-exposure adolescent smokers, above and beyond the risks posed by smoking behavior and nicotine dependence. Moreover, parental smoking is associated with early-onset nicotine dependence in low-exposure adolescent smokers. As an easily measureable risk factor, parent smoking status can be used to identify and intervene with novice adolescent smokers who are at high risk for chronic smoking behavior.

DSM-IV alcohol abuse and dependence criteria characteristics for recent onset adolescent drinkers.

BACKGROUND: Little is known about the psychometric properties of alcohol abuse and dependence criteria among recent-onset adolescent drinkers, particularly for those who consume alcohol infrequently. This study evaluated how well DSM-IV alcohol dependence criteria measure an alcohol use disorder (AUD) construct for recent onset adolescent drinkers at different levels of drinking frequency. METHOD: Data were drawn from the National Survey on Drug Use and Health, a nationally representative sample of 9356 recent-onset adolescent drinkers, aged 12-21, who began drinking within the past year. Multiple group item response theory analysis was conducted to assess the 11 DSM-IV alcohol abuse and dependence criteria. RESULTS: Criteria most likely to be endorsed at lower AUD severity included "withdrawal," "problems at home, school or work" and "tolerance." The criteria "drinking larger amounts/longer period of time," "unsuccessful efforts to cut down" and "continuing to drink despite related health problems" were more likely to be endorsed at higher AUD severity. Two criteria, "tolerance" and "time spent getting, using or recovering from alcohol" showed differential item functioning between drinking frequency groups (<7 vs. ≥ 7 days in past month), with lower discrimination and severity for more frequent drinkers. DSM-IV criteria were most precise for intermediate levels of AUD severity. CONCLUSIONS: All but two DSM-IV criteria had consistent psychometric properties across drinking frequency groups. Symptoms were most precise for a narrow, intermediate range of AUD severity. Those assessing AUD in recent onset adolescent drinkers might consider additional symptoms to capture the full AUD continuum.

Alcohol use as a signal for sensitivity to nicotine dependence among recent onset smokers.

OBJECTIVE: This study evaluated the association between alcohol use, abuse and dependence and cigarette smoking to determine whether alcohol may signal greater sensitivity to nicotine dependence at very low levels of smoking. METHOD: Data were drawn from five annual National Surveys on Drug Use and Health and included individuals age 12 to 21 who reported first exposure to smoking within the past two years and smoking at least once in the past month. RESULTS: Both alcohol abuse and alcohol dependence were associated with increased likelihood of symptoms that seem to tap tolerance for nicotine. These included items such as "the amount you smoke has increased"; "needing to smoke a lot more now in order to be satisfied"; and "smoking much more before starting to feel anything". Alcohol dependence, but not abuse was associated with the remaining symptoms, "after not smoking for a while, needing to smoke to feel less restless and irritable"; "craving cigarettes after not smoking for a while"; and "worrying about running out of cigarettes". All associations were not better accounted for by either alcohol use or amount smoked. CONCLUSION: If causally associated, treatment of alcohol-use disorders may prevent or reduce the early emergence of nicotine dependence symptoms among new smokers, very early in the smoking uptake process. If instead alcohol disorders are a signal of sensitivity for nicotine dependence best accounted for by a third variable, then adolescents with alcohol dependence and/or abuse during early exposures to smoking represents an important subgroup that may benefit from interventions directly targeting this association.

An item response theory analysis of nicotine dependence symptoms in recent onset adolescent smokers.

INTRODUCTION: Given absence of a "gold standard" for measuring self-reported nicotine dependence, particularly among less experienced smokers, there is a need to evaluate existing measures to determine how well symptoms measure the underlying nicotine dependence construct and whether symptoms function differently for less experienced smokers. Study aims were to determine (1) likelihood of endorsement of individual symptoms at different levels of a nicotine dependence construct and the ability of symptoms to discriminate between different levels of this construct and (2) whether these symptom properties varied between nondaily and daily smokers. METHODS: We used multiple group item response theory analysis to evaluate nicotine dependence symptoms from the nicotine dependence syndrome scale based on a nationally representative sample of 8081 recent onset adolescent smokers from the national surveys on drug use and health. RESULTS: After controlling for age, gender, smoking quantity and length of smoking exposure, symptoms assessing tolerance were invariant across nondaily and daily smokers, and discriminated well between levels of the nicotine dependence construct. However, the majority of symptoms functioned differently for nondaily and daily smokers. These symptoms did not discriminate as well between levels of the nicotine dependence construct and were more likely to be endorsed at lower levels of this construct for daily smokers. DISCUSSION: A measure that encompasses a range of symptoms tapping different aspects of smoking may be ideally suited for nondaily adolescent smokers, while an ideal measure of nicotine dependence for daily smokers might also include more core diagnostic features of nicotine dependence such as withdrawal and tolerance.

DSM-IV nicotine dependence symptom characteristics for recent-onset smokers.

INTRODUCTION: This study evaluated how well DSM-IV nicotine dependence symptoms measure an underlying dependence construct for recent-onset daily and nondaily smokers. METHODS: Based on a nationally representative sample of 2,758 recent-onset adolescent smokers from the National Surveys on Drug Use and Health, we used multiple group item response theory analysis to assess 7 symptoms representing DSM-IV diagnostic features of nicotine dependence. RESULTS: After controlling for age, gender, current smoking quantity, and length of smoking exposure, all 7 DSM-IV symptoms were invariant across nondaily and daily smokers and discriminated well among levels of the nicotine dependence construct. Symptoms most likely to be endorsed at lower levels of the dependence construct included spending more time getting, using, or getting over the effects of smoking and wanting or trying to stop or cut down. Symptoms most likely to be endorsed only at higher levels of the construct included giving up important activities and emotional/psychological and health problems related to smoking. DSM-IV symptoms were most precise for moderately high levels of the dependence construct and less precise for lower levels for both nondaily and daily smokers. DISCUSSION: DSM-IV nicotine dependence symptoms appear to have desirable psychometric properties for measuring a nicotine dependence construct among recent-onset adolescent smokers at both daily and nondaily levels, providing justification for the use of these symptoms in a measure that aims to evaluate the full continuum of nicotine dependence severity in this population.

Nicotine dependence symptoms among recent onset adolescent smokers.

The present study examined the prevalence of individual nicotine dependence symptoms among recent onset smokers across the continuum of nondaily and daily cigarette smoking behavior in a nationally representative sample of recent onset smokers from the National Surveys on Drug Use and Health (NSDUH). Rates of endorsement for 17 symptoms drawn primarily from the Nicotine Dependence Symptom Scale (Shiffman et al., 2004) were calculated for four levels of nondaily (smoked 1-3, 4-10, 11-20, or 21-29 days in the past 30 days) and daily (smoked 1, 2-5, 6-15, or >15 cigarettes per day in the past 30 days) smoking. Logistic and linear regression analyses with polynomial contrasts controlling for age, gender, length of exposure, and smoking quantity tested trends in symptom endorsement across levels of smoking. Significant linear and quadratic trends indicated that increasing rates of endorsement differed most between the lowest levels of nondaily and daily smoking. Results suggest that, for some, infrequent smoking may not represent benign experimentation. Recognizing early symptoms of nicotine dependence may assist in early identification and intervention of those at risk for heavier smoking in the future. Adolescents can be taught to recognize the early symptoms of nicotine dependence to increase awareness of the rapidity at which these symptoms may appear.

Smoking trajectories, health, and mortality across the adult lifespan.

This study extends research on the association between smoking behavior and chronic disease by following a cohort from the time of initiation of regular smoking patterns into old age and by examining the association of lifetime smoking trajectories with chronic disease and mortality. Participants consisted of 232 males selected from the Harvard classes of 1942-1944 and followed biennially through 2003. Five distinct smoking trajectories were identified based on the age at which participants quit daily smoking. Participants following smoking trajectories with later cessation had a higher likelihood of developing lung disease and lived shorter lives than those who quit smoking at an earlier age. This study confirms that the earlier a smoker quits, the greater the health benefits, and that these benefits are observed even decades after smoking cessation. Additionally, by showing different survival rates between trajectory groups 25 and 40 years after quitting, the results run counter to previous work that has found no difference in mortality between smokers and non-smokers 15 years after cessation.