Smoking and young people's mental health

Association between lower estimated premorbid intelligence quotient and smoking behavior in patients with schizophrenia

Aim

We aimed to investigate the involvement of premorbid intelligence quotient in higher prevalence of smoking in patients with schizophrenia.

Methods

Participants included 190 patients with schizophrenia (mean ± standard deviation age: 37.7 ± 10.8 years; 88 males and 102 females) and 312 healthy individuals (mean ± standard deviation age: 38.1 ± 13.8; 166 males and 146 females), matched for age, sex, and ethnicity (Japanese). Premorbid intelligence quotient was estimated using the Japanese Adult Reading Test and distress symptoms were assessed using the Hopkins Symptom Check List. Current smoking information was collected according to self-declarations.

Results

As expected, the smoking rate was higher, while mean education level and Japanese Adult Reading Test scores were significantly lower, in patients with schizophrenia than in healthy individuals (p < 0.01). The mean education level and Japanese Adult Reading Test scores were significantly lower in the smoker group than in the non-smoker group in both patients and healthy individuals (p < 0.05). In the patient group alone, Hopkins Symptom Check List subscale and total scores were significantly higher in the smoker group than in the non-smoker group (p < 0.05). A multivariate regression analysis showed that the Japanese Adult Reading Test score was a significant and negative predictor for smoking (p < 0.001, odds ratio = 0.97; 95% confidence interval: 0.96–0.99).

Conclusion

Our results suggest that lower estimated premorbid intelligence quotient is an important variable in elucidating smoking behavior in humans and may be associated with higher prevalence of smoking in patients with schizophrenia.

•

Lower premorbid intelligence quotient (IQ) was observed in patients with schizophrenia who were smokers.

•

Lower education level was observed in patients with schizophrenia who were smokers.

•

Lower premorbid IQ and education level were also seen in smokers in the healthy group.

•

Distress symptoms were higher in smokers with schizophrenia.

•

In total, premorbid IQ was a negative predictor for smoking.

Nicotine and cigarette smoke modulate Nrf2-BDNF-dopaminergic signal and neurobehavioral disorders in adult rat cerebral cortex. Hum Exp Toxicol 2018;37:540-556. [PMID: 28641491 DOI: 10.1177/0960327117698543]

BACKGROUND

Nicotine and cigarette smoking (CS) are associated with addiction behavior, drug-seeking, and abuse. However, the mechanisms that mediate this association especially, the role of brain-derived neurotrophic factor (BDNF), dopamine (DA), and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling in the cerebral cortex, are not fully known. Therefore, we hypothesized that overexpression of BDNF and DA, and suppression of Nrf2 contribute to several pathological and behavioral alterations in adult cerebral cortex. Methodology/Principal Observations: We treated Wistar rats with different doses of oral nicotine and passive CS for 4-week (short-term) and 12-week (long-term) duration, where doses closely mimic the human smoking scenario. Our result showed dose-dependent association of anxiogenic and depressive behavior, and cognitive interference with neurodegeneration and DNA damage in the cerebral cortex upon exposure to nicotine/CS as compared to the control. Further, the results are linked to upregulation of oxidative stress, overexpression of BDNF, DA, and DA marker, tyrosine hydroxylase (TH), with concomitant downregulation of ascorbate and Nrf2 expression in the exposed cerebral cortex when compared with the control.

CONCLUSION/SIGNIFICANCE

Overall, our data strongly suggest that the intervention of DA and BDNF, and depletion of antioxidants are important factors during nicotine/CS-induced cerebral cortex pathological changes leading to neurobehavioral impairments, which could underpin the novel therapeutic approaches targeted at tobacco smoking/nicotine's neuropsychological disorders including cognition and drug addiction.

Individual differences in the behavioral effects of nicotine: A review of the preclinical animal literature

Not everyone who tries tobacco or other nicotine-containing products becomes a long-term user. Certain traits or factors that are differentially present in these individuals must be able to help health care providers and researchers determine who is more likely to become chronic users of nicotine-containing products. Some of these factors, particularly sensation-seeking/novelty, impulsivity, and anxiety, lend themselves to the creation of animal models of reactivity to nicotine. These models of reactivity to nicotine can improve the translational aspects of preclinical animal research on nicotine-induced behaviors and treatments in order to help reduce negative outcomes in human populations. The goal of this review is to evaluate the current status of animal models of individual differences that serve to predict the later behavioral effects of nicotine. The limited utility and inconsistency of existing novelty models is considered, as well as the promise of impulsivity and anxiety models in preclinical animal populations. Finally, other models that could be employed to extend the benefit of the current research are examined.

Subjective well-being and hookah use among adults in the United States: A nationally-representative sample

BACKGROUND

Using a nationally-representative dataset of adults 18-30 years old in the United States, this study examined the relationship between hookah use and subjective well-being. Levels of sadness, happiness, tiredness, pain, and stress were compared between persons who have used hookah and those who have not.

METHODS

Data were merged from the Tobacco Use Supplement of the Current Population Survey, the American Time Use Survey, and the Subjective Well-being Supplement to the American Time Use Survey for the years 2010-2012 for persons 18-30 years old (n=1147). Wald tests were used to compare mean differences in subjective well-being between hookah users and non-users. Lastly, multivariable regression was used to determine whether there were significant differences in subjective well-being between hookah users and non-users, controlling for demographic factors, self-perceived health, and cigarette smoking.

RESULTS

The lifetime prevalence rate of hookah use was 5.2% among 18-30 year olds. Hookah users reported higher levels of stress and sadness than non-users. These relationships remained significant after controlling for demographic characteristics, self-perceived health, and cigarette use. The results were robust to the use of different statistical models, different age cut-offs, the inclusion of additional covariates (such as income and population density), and separate analyses by sex.

CONCLUSIONS

Hookah use is an emerging public health issue associated with increased levels of stress and sadness. Similar to cigarette use, healthcare providers may consider expanding their screening tests to include hookah use. Public policy geared toward greater prevention and control of hookah use is also recommended.

Predictors of persistent nicotine dependence among adults in the United States

BACKGROUND

Evidence suggests that nicotine dependence is the key barrier to successful smoking cessation. No previous study has documented predictors of persistent nicotine dependence among adults in the community. The goal of this study is to prospectively identify predictors of continued nicotine dependence over a 3-year period among adults.

METHODS

Data were drawn from Waves I and II of the National Epidemiologic Survey of Alcohol and Related Conditions (NESARC), a nationally representative sample of 34,653 adults in the United States. Logistic regression analyses were used to estimate the odds of persistent nicotine dependence at Wave 2 given the presence of various sociodemographic and psychiatric predictors at Wave 1.

RESULTS

Mood, anxiety, personality and illicit substance use disorders were associated with significantly increased risk of persistent nicotine dependence. The strength of these relationships was attenuated slightly after adjusting for demographic differences, but remained statistically significant. Persistent nicotine dependence was more common among unmarried, younger females with lower income levels and lower educational attainment.

CONCLUSIONS

To our knowledge, this study is the first to prospectively identify predictors of persistent nicotine dependence among adults. Our results suggest that the incorporation of mental health treatment into alternative smoking cessation approaches may help to increase the effectiveness of these programs and that a greater focus of these services on vulnerable segments of the population is needed in order to reduce continued disparities in smoking in the general population.

Onset and persistence of daily smoking: the interplay of socioeconomic status, gender, and psychiatric disorders

Gains in reducing the prevalence of smoking observed over the past 40 years have been substantially lower among lower socioeconomic status (SES) groups and women. In parallel, there have been strong and consistent associations of psychiatric disorders with SES, gender, and smoking. Yet few studies have examined the interrelations among these factors to identify their unique and shared contributions. In this study we examine (1) to what degree SES and gender predict new onset of daily smoking and persistence during the current period when rates of smoking have been stable overall; and (2) given the association of psychiatric disorders with gender, SES, and cigarette smoking, to what degree psychiatric disorders explain or alter the associations between gender, SES, and cigarette smoking.

METHODS

Longitudinal data for U.S. adults come from Waves 1 (2001-2002) and 2 (2003-2004) of the National Epidemiologic Study of Alcohol and Related Conditions (N=34,653). DSM-IV mood, anxiety, and substance use disorders were assessed with AUDADIS-IV. Logistic regression was used to estimate risk of transitions to daily smoking and persistence over the 3-year follow-up.

RESULTS

Gender, education, occupation, anxiety disorders, and substance use disorders (SUDs) independently predicted the onset of daily smoking at W2, with greater gender differences observed at lower levels of education. However, no interactions were found between active psychiatric disorders and either gender or SES in predicting the onset of daily smoking. Only being Native American/Alaskan, having an active SUD, and number of cigarettes smoked per day predicted persistence of daily smoking at W2.

[Smoking and nicotine dependence]

BACKGROUND

The prevalence of smoking is decreasing. At the same time, studies suggest that the relative proportion of nicotine dependent smokers is increasing. This may leave us with a smaller, but more problematic group of smokers. Few studies have investigated nicotine dependence in Norway.

MATERIAL AND METHODS

Data were collected in the Young in Norway Longitudinal Study, where 2,890 respondents were followed up from their early teens until their late 20s. Information was collected on smoking habits, nicotine dependence, education, various indicators of social marginalization, anxiety, depression, suicidal behaviour, alcohol problems and use of drugs.

RESULTS

At the age of 28 years, 12 % (n = 357) were classified as non-dependent daily smokers, whereas 5 % (n = 148) fulfilled criteria for "weak" and 3 % (n = 93) for "strong" nicotine dependence. 74 % of those who were in the "strong" dependent group at age 22 were still daily smokers at age 28; versus 50 % of non-dependent smokers. Nicotine dependence was associated with weak social resources, reduced mental health, alcohol problems and use of illegal drugs.

INTERPRETATION

Daily smokers are more or less nicotine dependent. Smokers with a strong dependency have more stable smoking habits, weaker social resources and more problems with mental health, alcohol and drug use than others. Nicotine dependence represents a larger health political challenge for the authorities than previously recognised.

Adult versus adolescent onset of smoking: how are mood disorders and other risk factors involved?

AIMS

To examine the strength of association between smoking and mood disorders and the association between smoking and its traditional risk factors, comparing those who started smoking in adolescence with those who started smoking in early adulthood.

DESIGN AND PARTICIPANTS

The analyses relied on prospective data from the Zurich Study. This longitudinal community study started in 1979 with a stratified sample of 591 participants aged 20/21 years, weighted towards those with mental disorders. Follow-up interviews were conducted at ages 23, 28, 30, 35 and 41.

MEASUREMENTS

In this analysis the adult versus adolescent onset of smoking was regressed on the cumulative prevalence of mood disorders, personality characteristics measured by the Freiburg Personality Inventory, common risk factors such as parental smoking, conduct and school problems, troubles with the family and basic socio-demographic variables (sex, education).

FINDINGS

In the Zurich Study cohort we found that 61.6% were former or current smokers, of whom 87% started smoking before the age of 20 and 13% after the age of 20. Adolescent onset of smoking was associated strongly with later major depression, dysthymia or bipolar disorders and, furthermore, with parental smoking, extroverted personality and discipline problems and rebelliousness in youth. However, only depression and dysthymia were associated with adult onset smoking and other risk factors associated with smoking were not so associated in this group.

CONCLUSIONS

Correlates of smoking onset in adolescence are mainly not applicable to the onset of smoking in young adulthood. Smoking onset beyond adolescence is an open research issue.

Nicotine exposure during adolescence induces a depression-like state in adulthood

There is a strong link between tobacco consumption and mood disorders. It has been suggested that afflicted individuals smoke to manage mood, however, there is evidence indicating that tobacco consumption can induce negative mood. This study was designed to investigate whether nicotine exposure during adolescence influences emotionality/behavioral functioning later in life. Adolescent (postnatal days, PD 30-44) male rats were treated with twice-daily injections of nicotine (0, 0.16, 0.32, or 0.64 mg/kg) for 15 consecutive days, and their behavioral reactivity to various behavioral paradigms (the elevated plus maze (EPM), sucrose preference, locomotor activity in the open field, and forced swim test (FST) was assessed 24 h (short term) or 1-month (long term) after exposure. Separate groups of adult rats received nicotine (0.32 mg/kg) to control for age-dependent effects. We report that nicotine exposure during adolescence-but not adulthood-leads to a depression-like state manifested in decreased sensitivity to natural reward (sucrose), and enhanced sensitivity to stress- (FST) and anxiety-eliciting situations (EPM) later in life. Our data show that behavioral dysregulation can emerge 1 week after drug cessation, and that a single day of nicotine exposure during adolescence can be sufficient to precipitate a depression-like state in adulthood. We further demonstrate that these deficits can be normalized by subsequent nicotine (0.32 mg/kg) or antidepressant (ie fluoxetine or bupropion; 10 mg/kg) treatment in adulthood. These data suggest that adolescent exposure to nicotine results in a negative emotional state rendering the organism significantly more vulnerable to the adverse effects of stress. Within this context, our findings, together with others indicating that nicotine exposure during adolescence enhances risk for addiction later in life, could serve as a potential model of comorbidity.