Effects of acute tobacco abstinence in adolescent smokers compared with nonsmokers

Associations of DHEA(S) with negative and positive affect in people who smoke daily with elevated and low depression symptoms: A pilot laboratory study

BACKGROUND

Individuals with depression symptoms have a harder time quitting smoking. High negative affect and low positive affect are core depression symptoms and arise following cigarette abstinence. Investigating associations of biological markers with negative and positive affect may provide valuable information about factors relevant to smoking cessation in individuals with elevated depression symptoms.

METHODS

Depression symptoms were measured at a baseline session. Participants then completed two counterbalanced experimental sessions (non-abstinent, abstinent) and completed measures of positive and negative affect, and provided saliva samples. Saliva samples were assayed at the Salimetrics' SalivaLab (Carlsbad, CA) using the Salimetrics Salivary Dehydroepiandrosterone (DHEA) Assay Kit (Cat. No. 1-1202) and Dehydroepiandrosterone-sulfate (DHEA-S) Assay Kit (Cat. No. 1-1252).

RESULTS

There were no main or interactive associations of DHEA with negative affect. However, there were significant DHEAS × experimental session and DHEAS × experimental session × depression symptom level interactions with negative affect. In the high depression symptom group, DHEAS positively associated with negative affect during the non-abstinent experimental session, but DHEAS negatively associated with negative affect during the abstinent experimental session. There were no associations of DHEA or DHEAS with positive affect.

CONCLUSION

This study found that DHEAS negatively associated with negative affect during cigarette abstinence in individuals with elevated depression symptoms. This is important as high negative affect during cigarette abstinence may result in a return to smoking.

Development of anxiety-like behaviors during adolescence: Persistent effects of adolescent morphine exposure in male rats

Epidemiological studies show the prevalence of opioid use, misuse and abuse in adolescents, which imposes social and economic accountability worldwide. Chronic opioid exposure, especially in adolescents, may have lasting effects on emotional behaviors that persist into adulthood. The current experiments were therefore designed to study the effects of sustained opioid exposure during adolescence on anxiety-like behaviors. Adolescent male Wistar rats underwent increasing doses of morphine for 10 days (PNDs 31-40). After that the open field test (OFT) and elevated plus maze (EPM) test were performed over a 4-week postmorphine treatment from adolescence to adulthood. Moreover, the weight of the animals was measured at these time points. We found that chronic adolescent morphine exposure reduces the weight gain during the period of morphine treatment and 4 weeks after that. It had no significant effect on the locomotor activity in the animals. Moreover, anxiolytic-like behavior was observed in the rats exposed to morphine during adolescence evaluated by OFT and EPM test. Thus, long-term exposure to morphine during adolescence has the profound potential of altering the anxiety-like behavior profile in the period from adolescence to adulthood. The maturation of the nervous system can be affected by drug abuse during the developmental window of adolescence and these effects may lead to behaviorally stable alterations.

Severity of negative mood and anxiety symptoms occurring during acute abstinence from tobacco: A systematic review and meta-analysis

This review was conducted with the following goals: To quantify the severity of mood and anxiety symptoms emerging during acute abstinence from tobacco (1). To explore sex differences related to the experience of specific symptoms (2). To investigate the early time course of symptoms (3). A meta-analysis was performed from 28 studies assessing mood and anxiety symptoms during the earliest phases of tobacco abstinence (up to 24 hrs post-quit) conducted from 1999 to 2019. Results revealed a significant (p < 0.0001) increase in 'anxiety', 'anger/irritability', 'depressed mood /sadness', and composite negative affect ('NA') in the 24 hours following smoking cessation. The largest effect size was detected for 'anxiety' (0.63). A qualitative analysis was performed to investigate sex differences and the time course of the specific symptoms. Results indicated that female smokers may experience worse mood symptoms compared to male smokers and that these symptoms may emerge within 3 hrs post-quit. Smoking cessation programs should implement sex-tailored interventions in order to improve their effectiveness, while future research should focus on alternative methods of nicotine administration.

Assessment of pain in adolescents: Influence of gender, smoking status and tobacco abstinence

PURPOSE

We examined sex differences between smokers and nonsmokers in pain threshold, tolerance, and intensity and the effect of pain on cardiovascular measures, withdrawal, and craving during acute smoking abstinence.

METHODS

Ninety-six (53 smokers, 43 nonsmokers) adolescents completed the Cold Pressor Task (CPT) to assess pain responses after minimal (1h) and 42-hour smoking deprivation. Vital signs and craving were assessed before and after CPT completion.

RESULTS

Smokers, compared to nonsmokers, had significantly lower pain tolerance (p<0.01) and pain threshold (p<0.001). Female smokers had significantly lower pain tolerance prior to, and following, 42-hour deprivation compared to male smokers (p's<0.01), male nonsmokers (p's<0.01), and female nonsmokers (p's<0.001), while male smokers demonstrated significantly decreased pain tolerance following 42-hour deprivation (p<0.05). Additionally, during minimal deprivation, at time of hand removal, female smokers had higher pain intensity compared to female nonsmokers (p<0.05) and male smokers (p<0.01). Withdrawal was not significantly correlated with any CPT measures or subjective pain during or following minimal deprivation or acute abstinence. Craving was associated with pain 15s after hand submersion (p=0.007) at 42-hour deprivation.

CONCLUSIONS

Smokers had a lower pain threshold than non-smokers, with female smokers demonstrating lower pain tolerance during minimal deprivation than all comparison groups, and, continuing to have diminished pain tolerance compared to female nonsmokers following 42h of abstinence. Male smokers demonstrated tobacco-deprivation-induced reductions in pain tolerance. Further study of pain-related factors that may contribute to relapse and maintenance of smoking behaviors, and mechanisms of these relationships among adolescent smokers is warranted.

Adolescent brain maturation and smoking: what we know and where we're headed

Smoking is a leading cause of mortality and morbidity worldwide. Smoking initiation often occurs during adolescence. This paper reviews and synthesizes adolescent development and nicotine dependence literatures to provide an account of adolescent smoking from onset to compulsive use. We extend neurobiological models of adolescent risk-taking, that focus on the interplay between incentive processing and cognitive control brain systems, through incorporating psychosocial and contextual factors specific to smoking, to suggest that adolescents are more vulnerable than adults to cigarette use generally, but that individual differences exist placing some adolescents at increased risk for smoking. Upon smoking, adolescents are more likely to continue smoking due to the increased positive effects induced by nicotine during this period. Continued use during adolescence, may be best understood as reflecting drug-related changes to neural systems underlying incentive processing and cognitive control, resulting in decision-making that is biased towards continued smoking. Persistent changes following nicotine exposure that may underlie continued dependence are described. We highlight ways that interventions may benefit from a consideration of cognitive-neuroscience findings.

Are tobacco dependence and withdrawal related amongst heavy smokers? Relevance to conceptualizations of dependence

Measured tobacco dependence is typically only modestly related to tobacco withdrawal severity among regular smokers making a quit attempt. The weak association between dependence and withdrawal is notable because it conflicts with core theories of dependence and because both measures predict cessation outcomes, suggesting they both index a common dependence construct. This study used data from a smoking cessation comparative effectiveness trial (N = 1504) to characterize relations of tobacco dependence with craving and negative affect withdrawal symptoms using multiple dependence measures and analytic methods to detect both additive and interactive effects and to determine whether withdrawal meaningfully mediates the influence of dependence on smoking cessation. We conclude: (a) Although univariate analyses suggest dependence and withdrawal measures are only modestly interrelated, more powerful analytic techniques show they are, in fact, meaningfully related and their shared variance is associated with cessation likelihood; (b) there are clear differences between craving and negative affective withdrawal symptoms, with the former more related to smoking heaviness and the latter related to trait measures of negative affect; moreover, craving more strongly mediates dependence effects on cessation; and (c) both craving and negative affect withdrawal symptoms are strongly related to a pattern of regular smoking that is sensitive to the passage of time and powerfully affected by smoking cues. These findings support models that accord an important role for associative processes and withdrawal symptoms, especially craving, in drug dependence. The findings also support the use of withdrawal variables as criteria for the evaluation of dependence measures.

Adolescent rats are resistant to adaptations in excitatory and inhibitory mechanisms that modulate mesolimbic dopamine during nicotine withdrawal

Adolescent smokers report enhanced positive responses to tobacco and fewer negative effects of withdrawal from this drug than adults, and this is believed to propel higher tobacco use during adolescence. Differential dopaminergic responses to nicotine are thought to underlie these age-related effects, as adolescent rats experience lower withdrawal-related deficits in nucleus accumbens (NAcc) dopamine versus adults. This study examined whether age differences in NAcc dopamine during withdrawal are mediated by excitatory or inhibitory transmission in the ventral tegmental area (VTA) dopamine cell body region. In vivo microdialysis was used to monitor extracellular levels of glutamate and gamma-aminobutyric acid (GABA) in the VTA of adolescent and adult rats experiencing nicotine withdrawal. In adults, nicotine withdrawal produced decreases in VTA glutamate levels (44% decrease) and increases in VTA GABA levels (38% increase). In contrast, adolescents did not exhibit changes in either of these measures. Naïve controls of both ages did not display changes in NAcc dopamine, VTA glutamate, or VTA GABA following mecamylamine. These results indicate that adolescents display resistance to withdrawal-related neurochemical processes that inhibit mesolimbic dopamine function in adults experiencing nicotine withdrawal. Our findings provide a potential mechanism involving VTA amino acid neurotransmission that modulates age differences during withdrawal.

Effects of nicotine on electroencephalography and affect in adolescent females with major depressive disorder: a pilot study

BACKGROUND

Given that smoking is typically initiated during adolescence, and that this period in brain development seems to be uniquely sensitive to nicotine, depressed youth may be most susceptible to the neuromodulatory and mood-altering effects of nicotine. Electroencephalographic (EEG) studies suggest that individuals with major depressive disorder (MDD) exhibit left frontal lobe hypoactivation (indexed by increased EEG alpha), a region implicated in positive affect regulation, as well as right parietal hypoactivation. Smoking/nicotine abstinence has been associated with increased left frontal and right parietal alpha activity (reduced activation), which has been correlated with increased depression ratings; nicotine administration seems to normalize this depression-associated asymmetry.

OBJECTIVES

This pilot study investigated whether acute nicotine administration in adolescent female smokers with MDD would alter resting EEG activity and affect.

METHODS

Subjective mood ratings and EEG recordings were acquired before and 2 hours after administering a transdermal placebo or nicotine (21 mg) patch to 8 adolescent female smokers with MDD.

RESULTS

Nicotine induced a modest increase in alpha1 amplitude in the right hemisphere and simultaneously decreased left-favoring alpha1 amplitude asymmetry. It also attenuated left alpha1 and alpha2 amplitude in the central region. Consistent with nicotine's stimulatory action, nicotine decreased theta amplitude in the right parietal region. No accompanying mood alterations were found, although smoking withdrawal and craving as well as physical symptom scores were reduced with nicotine.

CONCLUSIONS

The results of this pilot study, the first to examine the electrocortical effects of nicotine in depressed adolescents, indicate that nicotine modulates EEG asymmetry measures, laying the stage for further research regarding the role of nicotine on affective neurocircuitry in this population.

Behavioral effects of nicotine withdrawal differ by genetic strain in male and female adolescent rats

INTRODUCTION

Gender and ethnicity are powerful predictors of initiation and maintenance of cigarette smoking in adults but less is known about their role in smoking in adolescents. Consistent with human studies, rat models also reveal sex and strain differences in response to nicotine administration.

METHODS

This research examined nicotine withdrawal behaviors in 96 adolescent, male and female, Sprague Dawley (SD) and Long Evans (LE) rats. Rats received seven days continuous subcutaneous infusion of saline or 3.16 mg/kg nicotine via Alzet osmotic minipumps. Behavioral observations were made before, during, and after saline or nicotine administration. Occurrences of six specific behaviors were quantified: abnormal posture or movement, abnormal grooming, whole-body shakes, ptosis, empty-mouth chewing/teeth chattering, and diarrhea.

RESULTS

SD male and female rats that received nicotine displayed significantly more withdrawal behaviors 1 and 2 days after cessation of nicotine administration compared with rats that had received saline. LE male rats that received nicotine displayed significantly more withdrawal behaviors 1 day but not 2 days after cessation of nicotine administration compared with males that received saline. LE females showed no significant withdrawal behaviors after cessation of nicotine administration.

CONCLUSION

Results indicate that nicotine withdrawal in adolescent rats depends on sex and strain.

Nicotine withdrawal produces a decrease in extracellular levels of dopamine in the nucleus accumbens that is lower in adolescent versus adult male rats

The behavioral effects of nicotine withdrawal are lower in adolescent versus adult rats. However, the neurochemical mechanisms that mediate these developmental differences are unknown. Previous studies have shown that extracellular levels of dopamine in the nucleus accumbens (NAcc) are reduced in adult rats experiencing withdrawal. This study compared dopamine levels in the NAcc of male adolescent and adult rats experiencing nicotine withdrawal. Animals were prepared with subcutaneous pumps that delivered an equivalent nicotine dose in these age groups. Following 13 days of nicotine exposure, rats were implanted unilaterally with microdialysis probes into the NAcc and ipsilateral ventral tegmental area (VTA). The next day, dialysate levels were collected following systemic administration of the nicotinic-receptor antagonist mecamylamine to precipitate withdrawal. Mecamylamine produced an average % decrease in NAcc dopamine that was lower in adolescents (20%) versus adults (44%). Similar developmental differences were observed with the dopaminergic (DOPAC and HVA) but not serotonergic (5-HIAA) metabolites. A follow-up study compared NAcc dopamine in adolescent and adult rats receiving intra-VTA administration of bicuculline, which reduces gamma-aminobutyric acid (GABA) inhibition of dopamine transmission. The results revealed that blockade of GABA(A) receptors in the VTA produced a two-fold increase in NAcc dopamine of adults but not adolescents. These results provide a potential mechanism involving dopamine that mediates developmental differences in nicotine withdrawal. Specifically, they suggest that GABA systems are underdeveloped during adolescence and this reduced inhibition of dopamine neurons in the VTA may lead to reduced decreases in NAcc dopamine of young animals experiencing withdrawal.

Nicotine withdrawal and craving in adolescents: effects of sex and hormonal contraceptive use

While sex differences in the nicotine withdrawal (NW) symptoms and craving (NC) have been extensively described in adult cigarette smokers, few studies have investigated these phenomena in adolescents. We investigated the effect of gender and hormonal contraception (HC) on NW and NC during the first 14 days of cessation in adolescent smokers using data from a randomized, placebo-controlled, double-blind trial of the transdermal nicotine replacement therapy for smoking cessation. Analyses showed similar levels of NW severity in males and females, regardless of HC use. However, significantly higher NC was observed in females compared to males, (2.22+/-0.12 vs. 1.65+/-1.14; p=0.003). Further, females not using HC reported the highest level of NC (2.38+/-0.16) followed by females using HC (2.08+/-0.25) and males (1.71+/-0.16; p=0.007). The current findings suggest that adolescent females experience similar NW severity to males, but have stronger NC. Further, the use of hormonal contraceptives may impact the severity of craving. Addressing these different symptoms in adolescents may be useful in increasing smoking cessation rates in this special population of smokers.

Different affective response to opioid withdrawal in adolescent and adult mice

AIMS

Drug withdrawal is suggested to play a role in precipitating mood disorders in individuals with familial predisposition. Age-related differences in affective responses to withdrawal might explain the increased risk of mental illnesses when drug use begins during adolescence. Since there is a lack of animal research examining the effects of opioid withdrawal during adolescence, the present study examined whether there are age-related differences in affective responses to opioid withdrawal.

MAIN METHODS

Adolescent and adult mice were injected with two different morphine regimens, namely low and high, which differed in the dosage. Three and nine days following discontinuation of morphine administration, immobility time in the forced swim test (FST) and locomotion (total distance traveled) were evaluated.

KEY FINDINGS

On withdrawal day 3 (WD3), adolescent mice exhibited a decrease in immobility as compared to controls. No significant differences in immobility were observed on withdrawal day 9 (WD9). This effect on FST behaviors was not due to changes in overall motor activity, since no differences in locomotion were observed on either WD3 or WD9 in adolescent mice. In adults, no differences in either FST or locomotor behaviors were observed on WD3. As expected, on WD9, adult mice exhibited an increase in immobility and a decrease in locomotion.

SIGNIFICANCE

This study demonstrates age-dependent differences in both FST scores and locomotor behaviors during opioid withdrawal. FST behaviors are classically used to evaluate mood in rodents, thus this study suggests that opioid withdrawal might affect mood differentially across age.

A psychobiological framework of the substrates that mediate nicotine use during adolescence

Adolescents are especially likely to initiate tobacco use and are more vulnerable to long-term nicotine dependence. A unifying hypothesis is proposed based largely on animals studies that adolescents, as compared to adults, experience enhanced short-term positive and reduced aversive effects of nicotine, as well as less negative effects during nicotine withdrawal. Thus, during adolescence the strong positive effects of nicotine are inadequately balanced by negative effects that contribute to nicotine dependence in adults. This review provides a neural framework to explain developmental differences within the mesolimbic pathway based on the established role of dopamine in addiction. This pathway originates in the ventral tegmental area (VTA) and terminates in the nucleus accumbens (NAcc) where dopamine is increased by nicotine but decreased during withdrawal. During adolescence, excitatory glutamatergic systems that facilitate dopamine are overdeveloped, whereas inhibitory GABAergic systems are underdeveloped. Thus, it is hypothesized that adolescents display enhanced nicotine reward and reduced withdrawal via enhanced excitation and reduced inhibition of VTA cell bodies that release dopamine in the NAcc. Although this framework focuses on adolescents and adults, it may also apply to the understanding of enhanced vulnerability to nicotine in adults that were previously exposed to nicotine during adolescence. The hypothesis presented in this review suggests that the clinical diagnostic criteria developed for nicotine dependence in adults, based primarily on withdrawal, may be inappropriate during adolescence when nicotine withdrawal does not appear to play a major role in nicotine use. Furthermore, treatment strategies involving nicotine replacement may be harmful for adolescents because it may cause enhanced vulnerability to nicotine dependence later in adulthood.