Trajectories of criteria of nicotine dependence from adolescence to early adulthood

BACKGROUND

To identify patterns and correlates of developmental trajectories of DSM-IV nicotine dependence criteria from adolescence to early adulthood.

METHODS

The analytical sample of lifetime smokers (N=877) is from a longitudinal cohort of 6th-10th graders drawn from an urban school system. Subjects were interviewed 5 times at 6-month intervals and once 4.5 years later. Growth mixture models were estimated to identify trajectories of DSM-IV nicotine dependence criteria over ages 12-23.

RESULTS

A four-class solution fitted the data best: No dependence criteria (class 1, 32.0%); early onset/chronic course (class 2, 26.1%); early onset/remission (class 3, 15.4%); late onset (class 4, 26.5%). There appeared to be three critical periods. At ages 12-15, symptoms increased rapidly. As of age 16, the early onset/chronic class stabilized at high levels of symptoms, the early onset/remission class started its symptomatic decline, and the late onset class experienced a sharp increase in symptoms. At age 20, there was a convergence in the prevalence of symptoms experienced at high (classes 2 and 4) and low levels (classes 1 and 3). Extensiveness of smoking and marijuana use were associated with higher baseline levels of nicotine dependence criteria. Anxiety disorders were associated with all three symptomatic trajectories. Parental smoking and nicotine dependence were associated specifically with the early/chronic class, while pleasant initial sensitivity and earlier onset ages of cigarette and marijuana use characterized the two early onset classes (2 and 3).

CONCLUSIONS

Trajectories of dependence criteria constitute an advantageous phenotype for research and intervention over static summaries of smoking behaviors.

Molecular mechanism for a gateway drug: epigenetic changes initiated by nicotine prime gene expression by cocaine

In human populations, cigarettes and alcohol generally serve as gateway drugs, which people use first before progressing to marijuana, cocaine, or other illicit substances. To understand the biological basis of the gateway sequence of drug use, we developed an animal model in mice and used it to study the effects of nicotine on subsequent responses to cocaine. We found that pretreatment of mice with nicotine increased the response to cocaine, as assessed by addiction-related behaviors and synaptic plasticity in the striatum, a brain region critical for addiction-related reward. Locomotor sensitization was increased by 98%, conditioned place preference was increased by 78%, and cocaine-induced reduction in long-term potentiation (LTP) was enhanced by 24%. The responses to cocaine were altered only when nicotine was administered first, and nicotine and cocaine were then administered concurrently. Reversing the order of drug administration was ineffective; cocaine had no effect on nicotine-induced behaviors and synaptic plasticity. Nicotine primed the response to cocaine by enhancing its ability to induce transcriptional activation of the FosB gene through inhibition of histone deacetylase, which caused global histone acetylation in the striatum. We tested this conclusion further and found that a histone deacetylase inhibitor simulated the actions of nicotine by priming the response to cocaine and enhancing FosB gene expression and LTP depression in the nucleus accumbens. Conversely, in a genetic mouse model characterized by reduced histone acetylation, the effects of cocaine on LTP were diminished. We achieved a similar effect by infusing a low dose of theophylline, an activator of histone deacetylase, into the nucleus accumbens. These results from mice prompted an analysis of epidemiological data, which indicated that most cocaine users initiate cocaine use after the onset of smoking and while actively still smoking, and that initiating cocaine use after smoking increases the risk of becoming dependent on cocaine, consistent with our data from mice. If our findings in mice apply to humans, a decrease in smoking rates in young people would be expected to lead to a decrease in cocaine addiction.

Linking measures of adult nicotine dependence to a common latent continuum and a comparison with adolescent patterns

BACKGROUND

An ongoing debate regarding the nature of nicotine dependence (ND) is whether the same instrument can be applied to measure ND among adults and adolescents. Using a hierarchical item response model (IRM), we examined evidence for a common continuum underlying ND symptoms among adults and adolescents.

METHOD

The analyses are based on two waves of interviews with subsamples of parents and adolescents from a multi-ethnic longitudinal cohort of one thousand and thirty-nine 6-10th graders from the Chicago Public Schools (CPS). Adults and adolescents who reported smoking cigarettes the last 30 days prior to waves 3 and 5 completed three common instruments measuring ND symptoms and one item measuring loss of autonomy.

RESULTS

A stable continuum of ND, first identified among adolescents, was replicated among adults. However, some symptoms, such as tolerance and withdrawal, differed markedly across adults and adolescents. The majority of mFTQ items were observed within the highest levels of ND, the NDSS items within the lowest levels, and the DSM-IV items were arrayed in the middle and upper third of the continuum of dependence severity. Loss of autonomy was positioned at the lower end of the continuum. We propose a ten-symptom measure of ND for adolescents and adults.

CONCLUSIONS

Despite marked differences in the relative severity of specific ND symptoms in each group, common instrumentation of ND can apply to adults and adolescents. The results increase confidence in the ability to describe phenotypic heterogeneity in ND across important developmental periods.

Age-related differences in cigarette smoking among whites and African-Americans: evidence for the crossover hypothesis

BACKGROUND

Age crossover describes the age-related reversal in prevalence of current cigarette smoking among non-Hispanic whites and African-Americans, with prevalence higher among whites than African-Americans in adolescence but lower in adulthood. Prior studies have examined smoking patterns in separate adolescent and adult samples and have not sought to identify factors that could account for crossover. We conducted analyses using national samples to identify factors that account for crossover and estimate their impact on crossover age.

METHODS

Analyses are based on national samples of lifetime smokers 12-49 years old in the 2006-2008 aggregated National Surveys on Drug Use and Health (N=61, 757) (SAMHSA, 2007-2009) and on multiple birth cohorts followed over 21 cross-sectional surveys.

RESULTS

We identified crossover for cigarette smoking in the US population at about age 29. Crossover is partially explained by differences between whites and African-Americans in education and marital status, and more weakly by the opposite impact of age of smoking onset on persistence of smoking in the two groups. Controlling for smoking history, education and social role participation would raise crossover in current smoking by more than 14 years. Rates of current smoking among lifetime smokers at four different age categories in multiple birth cohorts followed from ages 12-17 to 35 and over in 21 surveys spanning 24 years confirm the age-related patterns observed cross-sectionally.

CONCLUSION

Age crossover for current smoking appears among whites and African-Americans. Efforts targeted toward improving educational levels of young people would have the strongest impact in decreasing persistent smoking, especially among African-Americans.

Risk and protective factors for nicotine dependence in adolescence

BACKGROUND

We investigated the role of psychosocial and proximal contextual factors on nicotine dependence in adolescence.

METHODS

Data on a multiethnic cohort of 6th to 10th graders from the Chicago public schools were obtained from four household interviews conducted with adolescents over two years and one interview with mothers. Structural equation models were estimated on 660 youths who had smoked cigarettes by the first interview.

RESULTS

Pleasant initial sensitivity to tobacco use, parental nicotine dependence (ND), adolescent ND and extensiveness of smoking at the initial interview had the strongest total effects on adolescent ND two years later. Perceived peer smoking and adolescent conduct problems were of lesser importance. Parental ND directly impacted adolescent ND two years later and had indirect effects through pleasant initial sensitivity and initial extensiveness of smoking. Parental depression affected initial adolescent dependence and depression but adolescent depression had no effect on ND. The model had greater explanatory power for males than females due partly to the stronger effect of conduct problems on dependence for males than females.

CONCLUSIONS

The findings underscore the importance of the initial drug experience and familial factors on adolescent nicotine dependence and highlight the factors to be the focus of efforts targeted toward preventing ND among adolescents.

Comorbid psychiatric disorders and nicotine dependence in adolescence

AIMS

To examine bidirectional influences of onset of psychiatric disorders and nicotine dependence among adolescent smokers.

DESIGN

A prospective longitudinal cohort of adolescents and mothers drawn from a large city school system. Adolescents were interviewed five times and mothers three times over 2 years.

SETTING

Chicago, Illinois.

PARTICIPANTS

Subsample of adolescent smokers (n = 814).

MEASUREMENTS

Selected DSM-IV psychiatric disorders, nicotine dependence and selected risk factors were ascertained.

FINDINGS

Among lifetime smokers, 53.7% experienced at least one nicotine dependence criterion; 26.1% full dependence; 14.1% experienced an anxiety disorder, 18.8% a mood disorder and 29.5% a disruptive disorder. Nicotine dependence and psychiatric disorders were comorbid: nicotine-dependent youths had higher rates of individual and multiple disorders than those not dependent. Controlling for other covariates, mood disorder and nicotine dependence did not predict each other; anxiety disorder predicted nicotine dependence. Bidirectional influences were observed for disruptive disorder and nicotine dependence. Predictors of onset of full nicotine dependence included earlier onset age of tobacco use, high initial pleasant sensitivity to tobacco, alcohol and illicit drug use, abuse and dependence and parental nicotine dependence. Predictors of psychiatric disorder onset included gender, race/ethnicity, other psychiatric disorders, illicit drug abuse or dependence and parental depression and delinquency.

CONCLUSIONS

Initial pleasant experiences of smoking are predictive of later development of nicotine dependence. There may be reciprocal influences between disruptive disorder and development of nicotine dependence in adolescence, and intergenerational transmission of parental nicotine dependence and psychopathology.

Educational attainment and smoking among women: risk factors and consequences for offspring

We examine the association between education and smoking by women in the population, including smoking during pregnancy, and identify risk factors for smoking and the consequences of smoking in pregnancy for children's smoking and behavioral problems. Secondary analyses of four national data sets were implemented: The National Survey of Drug Use and Health (2006), the National Longitudinal Survey of Youth (1979-2004); the National Longitudinal Survey of Adolescent Health (Wave III); National Health and Nutrition Examination Survey (2005-2006). The lower the level of education, the greater the risk of being a current smoker, smoking daily, smoking heavily, being nicotine dependent, starting to smoke at an early age, having higher levels of circulating cotinine per cigarettes smoked, and continuing to smoke in pregnancy. The educational gradient is especially strong in pregnancy. Educational level and smoking in pregnancy independently increase the risk of offspring smoking and antisocial and anxious/depressed behavior problems. These effects persist with control for other covariates, except maternal age at child's birth, which accounts for the impact of education on offspring smoking and anxious/depressed behavior problems. Women with low education should be the target of public health efforts toward reducing tobacco use. These efforts need to focus as much on social conditions that affect women's lives as on individual level interventions. These interventions would have beneficial effects not only for the women themselves but also for their offspring.

Comorbidity of psychiatric disorders and nicotine dependence among adolescents: findings from a prospective, longitudinal study

OBJECTIVE

To examine prospectively the comorbidity of DSM-IV psychiatric disorders and nicotine dependence in adolescence.

METHOD

A multiethnic sample (N = 1,039) of adolescents from grades 6 to 10 in the Chicago public schools (mean age 14.1 years) was interviewed at home five times, and mothers were interviewed three times over a 2-year period (2003-2005). Completion rates at each wave were 96% of the initial sample. Selected DSM-IV psychiatric disorders were ascertained from youths and mothers about youths at two annual waves with the NIMH Diagnostic Interview Schedule for Children, Version IV-Y and IV-P; DSM-IV symptoms of nicotine dependence were ascertained from youths at every wave using a measure developed for adolescents.

RESULTS

Psychiatric disorders most often preceded the onset of the first criterion of nicotine dependence. Prospective associations between psychiatric disorders and nicotine dependence were examined through logistic regressions. After controlling for comorbid disorders, it was found that lifetime disruptive disorder significantly predicted the onset of a nicotine dependence criterion (adjusted odds ratio 2.1). Early onset of any psychiatric disorder increased this risk. Other predictors included novelty seeking and extensiveness of smoking. By contrast, nicotine dependence did not predict the onset of a psychiatric disorder; significant predictors included the youths' prior other psychiatric disorders, novelty seeking, and parental depression and antisocial behavior.

CONCLUSIONS

Nicotine dependence does not seem to contribute to the onset of psychiatric disorders, whereas disruptive disorder is an important etiologic factor for nicotine dependence in adolescence.

ADOLESCENTS' INCONSISTENCY IN SELF-REPORTED SMOKING: A COMPARISON OF REPORTS IN SCHOOL AND IN HOUSEHOLD SETTINGS

Extent and sources of inconsistency in self-reported cigarette smoking between self-administered school surveys and household interviews was examined in two longitudinal multiethnic adolescent samples, the urban Transition to Nicotine Dependence in Adolescence (TND) (N = 832) and the National Longitudinal Study of Adolescent Health (Add Health) (N = 4,414). Inconsistency was defined as a positive report of smoking in school followed by a negative report in the household. Smoking questions were ascertained with paper-and-pencil instruments (PAPI-SAQ) in school in both studies, and computer-assisted personal interviewing (CAPI) in TND but audio computer-assisted self-interviewing (ACASI) in Add Health in the household. In TND, 23.5 percent of youths who reported smoking lifetime and 20.4 percent of those who reported smoking the last 12 months in the school survey reported in the household never having smoked; in Add Health, the latter was 8.6 percent. Logistic regressions identified five common correlates of inconsistency across the two studies: younger age, ethnic minority status, lesser involvement in deviant activities, having nonsmoking parents and friends. In TND, interviewing of youth and parent by the same interviewer increased inconsistent reporting. Matching the definition of inconsistent reporting and the age, gender and race/ethnic distributions of TND on an urban Add Health subsample reduced the predicted rate of inconsistency in TND. The estimated bias attributable to CAPI compared with ACASI methodology did not reach significance in the aggregated matched samples suggesting that irrespective of administration mode, household interviews decrease reporting of smoking, especially among younger, minority and more conventional youths embedded in a social network of nonsmokers.

On the development of nicotine dependence in adolescence

Little is known about the natural history of drug dependence. This article describes the development and predictors of DSM-IV nicotine dependence in adolescence when tobacco use is initiated. In a two-stage design, a survey was administered to 6th-10th graders in the Chicago Public Schools to select a cohort of adolescents. Household interviews were conducted with adolescents five times and with one parent (predominantly mothers) three times over 2 years. The analytical sample includes 353 youths, who started using tobacco within 12 months preceding Wave 1 or between Waves 1-5. Survival analysis estimated latency to individual DSM-IV nicotine dependence criteria and the full dependence syndrome. Twenty-five percent of youths experienced the syndrome within 23 months of tobacco use onset. Tolerance, impaired control and withdrawal were experienced most frequently. Youths who developed full dependence experienced their first symptom faster after tobacco use onset than those who experienced only one criterion through the end of the observation period. Cox proportional hazards models estimated the importance of time-constant and time-varying sociodemographic, tobacco and other drug use, parental and peer smoking, social psychological and biological risk factors for experiencing the first criterion and the full syndrome. Pleasant initial sensitivity to tobacco and number of cigarettes smoked the prior month predicted both outcomes. Parental dependence predicted the full syndrome. Significant covariates were generally the same across gender and racial/ethnic subgroups. The predictive significance of the initial smoking experience and parental dependence highlight the potential importance of genetic factors in the etiology of nicotine dependence.

Urine nicotine metabolites and smoking behavior in a multiracial/multiethnic national sample of young adults

Nicotine metabolism has been hypothesized to affect patterns of smoking. The recent development of a noninvasive measure of nicotine metabolism, the nicotine metabolite ratio (trans-3'-hydroxycotinine/cotinine), makes it possible to examine the association between rate of nicotine metabolism and smoking behavior in the general population. This US study examined group differences in the ratio measured in urine and the association between the ratio and multiple measures of smoking behavior and nicotine dependence in a large, national representative sample of young adults. The sample included 900 daily smokers aged 18-26 years from wave III (2001-2002) of the National Longitudinal Survey of Adolescent Health. Nicotine dependence was measured by using the Fagerström Test for Nicotine Dependence. Females had higher nicotine metabolite ratios than males; Whites and Hispanics had higher nicotine metabolite ratios than African Americans or Asians. This finding is consistent with those from laboratory studies of older smokers based on intravenous infusion of nicotine. No significant association was found between the nicotine metabolite ratio and number of cigarettes smoked per day or nicotine dependence. The availability of a noninvasive measure makes possible systematic testing of causal hypotheses generated by laboratory studies in the general population.

Salivary cotinine concentration versus self-reported cigarette smoking: Three patterns of inconsistency in adolescence

The present study examined the extent and sources of discrepancies between self-reported cigarette smoking and salivary cotinine concentration among adolescents. The data are from household interviews with a cohort of 1,024 adolescents from an urban school system. Histories of tobacco use in the last 7 days and saliva samples were obtained. Logistic regressions identified correlates of three inconsistent patterns: (a) Pattern 1-self-reported nonsmoking among adolescents with cotinine concentration above the 11.4 ng/mg cutpoint (n = 176), (b) Pattern 2-low cotinine concentration (below cutpoint) among adolescents reporting having smoked within the last 3 days (n = 155), and (c) Pattern 3-high cotinine concentration (above cutpoint) among adolescents reporting not having smoked within the last 3 days (n = 869). Rates of inconsistency were high among smokers defined by cotinine levels or self-reports (Pattern 1 = 49.1%; Pattern 2 = 42.0%). Controlling for other covariates, we found that reports of nonsmoking among those with high cotinine (Pattern 1) were associated with younger age, having few friends smoking, little recent exposure to smokers, and being interviewed by the same interviewer as the parent and on the same day. Low cotinine concentration among self-reported smokers (Pattern 2) was negatively associated with older age, being African American, number of cigarettes smoked, depth of inhalation, and exposure to passive smoke but positively associated with less recent smoking and depressive symptoms. High cotinine concentrations among self-reported nonsmokers was positively associated with exposure to passive smoke (Pattern 3). The data are consonant with laboratory findings regarding ethnic differences in nicotine metabolism rate. The inverse relationship of cotinine concentration with depressive symptoms has not previously been reported. Depressed adolescent smokers may take in smaller doses of nicotine than nondepressed smokers; alternatively, depressed adolescents may metabolize nicotine more rapidly.

On the measurement of nicotine dependence in adolescence: comparisons of the mFTQ and a DSM-IV-based scale

OBJECTIVE

To compare nicotine-dependent smokers identified by the modified Fagerström Tolerance Questionnaire (mFTQ) and a scale based on the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), in a multiethnic adolescent sample.

METHODS

A school survey was conducted on 6th- to 10th-grade students (N=15,007) in a large urban public school system.

RESULTS

The two scales formed two distinct factors. The concordance between the two classifications of nicotine dependence was low. The DSM identified a much larger number of nicotine-dependent smokers than the mFTQ, mostly because smokers met dependence criteria at much lower levels of cigarettes consumed, especially when they were depressed. Rates of dependence were higher among whites than minority-group members, especially African Americans. Control for level of cigarette consumption attenuated or eliminated ethnic differences.

CONCLUSIONS

This investigation provides some understanding of youths defined as dependent by each scale but cannot by itself indicate which scale better measures dependence. Differences in dependence rates among ethnic groups are accounted for mostly by quantity of cigarettes smoked.

Racial/ethnic differences in cigarette smoking initiation and progression to daily smoking: a multilevel analysis

OBJECTIVES

We sought to identify individual and contextual predictors of adolescent smoking initiation and progression to daily smoking by race/ethnicity.

METHODS

We used data from the National Longitudinal Study of Adolescent Health to estimate the effects of individual (adolescent, family, peer) and contextual (school and state) factors on smoking onset among nonsmokers (n = 5374) and progression to daily smoking among smokers (n = 4474) with multilevel regression models.

RESULTS

Individual factors were more important predictors of smoking behaviors than were contextual factors. Predictors of smoking behaviors were mostly common across racial/ethnic groups.

CONCLUSIONS

The few identified racial/ethnic differences in predictors of smoking behavior suggest that universal prevention and intervention efforts could reach most adolescents regardless of race/ethnicity. With 2 exceptions, important contextual factors remain to be identified.