Role of progesterone in nicotine addiction: evidence from initiation to relapse

A gut (microbiome) feeling about addiction: Interactions with stress and social systems

In recent years, an increasing attention has given to the intricate and diverse connection of microorganisms residing in our gut and their impact on brain health and central nervous system disease. There has been a shift in mindset to understand that drug addiction is not merely a condition that affects the brain, it is now being recognized as a disorder that also involves external factors such as the intestinal microbiota, which could influence vulnerability and the development of addictive behaviors. Furthermore, stress and social interactions, which are closely linked to the intestinal microbiota, are powerful modulators of addiction. This review delves into the mechanisms through which the microbiota-stress-immune axis may shape drug addiction and social behaviors. This work integrates preclinical and clinical evidence that demonstrate the bidirectional communication between stress, social behaviors, substance use disorders and the gut microbiota, suggesting that gut microbes might modulate social stress having a significance in drug addiction.

Substance Use Over Time Among Sexual and Gender Minority People: Differences at the Intersection of Sex and Gender

Purpose: Sexual and gender minority (SGM) people are at greater risk for substance use than heterosexual and cisgender people, but most prior work is limited by cross-sectional analyses or the examination of single substance use. This study examined substance use over time among SGM people to identify patterns of polysubstance use at the intersection of sex and gender. Methods: Data were collected annually over 4 years from SGM respondents (n = 11,822) in The Population Research in Identity and Disparities for Equality (PRIDE) Study. Differences in substance use patterns (any prior 30-day use of 15 substances) by gender subgroup were examined with latent class analysis, and multinomial regression models tested relationships between gender subgroup and substance use. Results: Eight classes of substance use were observed. The three most common patterns were low substance use (49%), heavy episodic alcohol use (≥5 alcoholic drinks on one occasion) with some cannabis and tobacco use (14%), and cannabis use with some tobacco and declining heavy episodic alcohol use (13%). Differences observed included lower odds of patterns defined by heavy episodic alcohol use with some cannabis and tobacco use in all gender subgroups relative to cisgender men and persons with low substance use (odds ratios [ORs] 0.26-0.60). Gender expansive people assigned female at birth, gender expansive people assigned male at birth, and transgender men had greater odds of reporting cannabis use with small percentages of heavy episodic alcohol and tobacco use (ORs: 1.41-1.60). Conclusion: This study suggests that there are unique patterns of polysubstance use over time among gender subgroups of SGM people.

The role of neurosteroids in posttraumatic stress disorder and alcohol use disorder: A review of 10 years of clinical literature and treatment implications

Rates of alcohol use disorder (AUD) are increasing in men and women and there are high rates of concurrent posttraumatic stress disorder (PTSD) and AUD. AUD and PTSD synergistically increase symptomatology and negatively affect treatment outcomes; however, there are very limited pharmacological treatments for PTSD/AUD. Neurosteroids have been implicated in the underlying neurobiological mechanisms of both PTSD and AUD and may be a target for treatment development. This review details the past ten years of research on pregnenolone, progesterone, allopregnanolone, pregnanolone, estradiol, testosterone and dehydroepiandrosterone/dehydroepiandrosterone-sulfate (DHEA/DHEA-S) in the context of PTSD and AUD, including examination of trauma/alcohol-related variables, such as stress-reactivity. Emerging evidence that exogenous pregnenolone, progesterone, and allopregnanolone may be promising, novel interventions is also discussed. Specific emphasis is placed on examining the application of sex as a biological variable in this body of literature, given that women are more susceptible to both PTSD diagnoses and stress-related alcohol consumption.

Acceptability of Hormonal Contraceptives as a Smoking Cessation Aid for Women of Reproductive Age: A Web-Based Cross-Sectional Survey

Introduction

Cigarette smoking is the most common cause of preventable cancers and other premature morbidity and mortality. Modifying hormonal patterns using hormonal contraceptives (HCs) may lead to improved smoking cessation outcomes in women, though the acceptability of this is unknown. Therefore, we explored the willingness of reproductive-age women who smoke to use HC for cessation.

Methods

A cross-sectional online survey was conducted with a convenience sample of reproductive-age women living in the United States who self-reported smoking combustible cigarettes. Questions covered smoking history, previous HC use, and willingness to use various HC methods (i.e., injectable, oral, patch, vaginal insert) for cessation. Chi-squared tests and logistic regression were conducted using StataBE 17.1.

Results

Of 358 eligible respondents, n = 312 (86.9%) reported previous HC use. Average age of those with HC use history was 32.1 ± 6.1 years compared with 27.8 ± 6.7 years for those without history of HC use (p = 0.001). Of respondents who reported previous HC use, 75.6% reported willingness to use HCs, compared with 60.9% of those without a history of HC use. Overall, willingness to use various types of HC ranged from 22.6% for the vaginal insert to 59.2% willing to use an oral contraceptive.

Discussion

These observations indicate that most women who smoke cigarettes are willing to use HC for a smoking cessation aid, especially if they have a history of HC use and with an oral form of HC. To improve the rate of smoking cessation for women of reproductive age, future interventions should explore how to incorporate HC for cessation.

Effects of Ovarian Hormone Levels on Stress, Cigarette Craving, and Smoking in a Laboratory Relapse Paradigm Among Females Who Smoke Daily

INTRODUCTION

Females, versus males, have shown a slower decline in smoking prevalence, greater smoking-related mortality and morbidity, and tend to have more difficulty achieving and maintaining abstinence. Identifying sex-specific risk factors is needed to improve outcomes. Though ovarian hormones have been evaluated for their role in smoking and relapse, measures tend to be static and infrequent, failing to capture the influence of increasing or decreasing levels.

AIMS AND METHODS

The present study evaluated the effect of static and fluctuating levels of ovarian hormones (ie, progesterone, estradiol, and estrogen to progesterone [E/P] ratio) on stress reactivity, cigarette craving, and smoking during a laboratory relapse paradigm. Female participants (assigned female at birth) reporting daily cigarette smoking (N = 91, ages 18-45) were recruited from the community. Participants provided daily salivary ovarian hormone levels leading up to a laboratory session, in which stress was induced and stress reactivity, cigarette craving, latency to smoke, and ad-libitum smoking were measured.

RESULTS

Static levels of estradiol were associated with stress reactivity (β = 0.28, SE = 0.13) and static E/P ratio was associated with smoking in the laboratory (HR = 1.4). Preceding 3-day changes in estradiol and E/P ratio, but neither static levels nor preceding 3-day changes in progesterone were associated with stress reactivity, cigarette craving, or smoking in a relapse paradigm.

CONCLUSIONS

Ovarian hormones are among several sex-specific factors involved in the complex neuroendocrine response to stress, and their interaction with other biological, social, and psychological factors in the real-world environment is not yet fully understood.

IMPLICATIONS

Findings of the present study provide novel information regarding the role of ovarian hormones among female participants who smoke daily in stress reactivity and smoking in the context of a laboratory relapse paradigm and highlight several avenues for future research. We found that same-day estradiol levels were associated with increased subjective stress reactivity and same-day estrogen to progesterone ratio was associated with increased likelihood of smoking in a relapse paradigm. Ovarian hormones are among several sex-specific factors contributing to the complex neuroendocrine response to stress, and their interaction with other biological, social, and psychological factors in the real-world environment is not yet fully understood.

Astrocytic Dagla Deletion Decreases Hedonic Feeding in Female Mice

Introduction: Endocannabinoids and exogenous cannabinoids are potent regulators of feeding behavior and energy metabolism. Stimulating cannabinoid receptor signaling enhances appetite, particularly for energy-dense palatable foods, and promotes energy storage. To elucidate the underlying cellular mechanisms, we investigate here the potential role of astrocytic endocannabinoid 2-arachidonoylglycerol (2-AG). Astrocytes provide metabolic support for neurons and contribute to feeding regulation but the effect of astrocytic 2-AG on feeding is unknown. Materials and Methods: We generated mice lacking the 2-AG synthesizing enzyme diacylglycerol lipase alpha (Dagla) in astrocytes (GLAST-Dagla KO) and investigated hedonic feeding behavior in male and female mice. Body weight and baseline water and food intake was characterized; additionally, the mice went through milk, saccharine, and sucrose preference tests in fed and fasted states. In female mice, the estrous cycle stages were identified and plasma levels of female sex hormones were measured. Results: We found that the effects of the inducible astrocytic Dagla deletion were sex-specific. Acute milk preference was decreased in female, but not in male mice and the effect was most evident in the estrus stage of the cycle. This prompted us to investigate sex hormone profiles, which were found to be altered in GLAST-Dagla KO females. Specifically, follicle-stimulating hormone was elevated in the estrus stage, luteinizing hormone in the proestrus, and progesterone was increased in both proestrus and estrus stages of the cycle compared with controls. Conclusions: Astrocytic Dagla regulates acute hedonic appetite for palatable food in females and not in males, possibly owing to a deregulated female sex hormone profile. It is plausible that endocannabinoid production by astrocytes at least partly contributes to the greater susceptibility to overeating in females. This finding may also be important for understanding the effects of exogenous cannabinoids on sex hormone profiles.

Methodological approach for an integrated female-specific study of anxiety and smoking comorbidity

Two primary ovarian hormones that fluctuate across the female menstrual cycle-estradiol and progesterone-have been independently linked in separate literatures to nicotine reinforcement and anxiety psychopathology. We identify existing methodological limitations in these literatures, describe an example protocol that was developed to address such limitations, highlight case examples, and offer insights on the resulting advantages and challenges. This protocol was an observational, prospective, within-subjects study of female cigarette smokers who were followed over the course of a complete menstrual cycle. Non-treatment seeking, female cigarette smokers (N = 50), between the ages of 18-40 who have a normal menstrual cycle (25-35 days in length) were recruited from the community. Females with anxiety or mood psychopathology represented 38.0% of the sample. Salivary progesterone and estradiol were assessed each morning via at-home saliva collection methods. Self-reported within-day momentary ratings of anxiety and nicotine reinforcement were collected using ecological momentary assessment (EMA) via a mobile app. Protocol compliance was >85%. Within- and between-subjects heterogeneity was observed in the progesterone and estradiol, anxiety, and nicotine craving measures, especially in the context of anxiety psychopathology. We aimed to integrate the anxiety and nicotine dependence literatures and advance the empirical study of the role of ovarian hormones. This protocol reflects an intensive, yet feasible approach to collecting daily-level naturalistic data related to estradiol, progesterone, anxiety, and nicotine reinforcement.

Liver tryptophan 2,3-dioxygenase: a determinant of anxiety-like behaviour - studies with chronic nicotine administration in rats

Deletion of the tryptophan 2,3-dioxygenase ( TDO2 ) gene induces an anxiolytic-like behaviour in mice and TDO inhibition by allopurinol elicits an antidepressant-like effect in rats exposed to restraint stress. Chronic nicotine administration inhibits TDO activity, enhances brain serotonin synthesis and exerts anxiolytic- and antidepressant-like effects in rodent models. There is a strong association between anxiety, depression and tobacco use, which is stronger in women than in men. The present study aimed to examine the relationship between behavioural measures of anxiety and depression with liver TDO activity, brain tryptophan concentration and serotonin synthesis in rats treated chronically with nicotine. Behavioural measures included the elevated plus maze (EPM), open field (OFT) and forced swim (FST) tests. Biochemical measures included TDO activity, serum corticosterone and brain Trp, 5-HT and 5-HIAA concentrations. Anxiolytic-like and antidepressant-like effects of chronic nicotine were confirmed in association with TDO inhibition and elevation of brain Trp and 5-HT. Sex differences in behaviour were independent of the biochemical changes. At baseline, female rats performed better than males in OFT and FST. Nicotine was less anxiolytic in females in the open arm test. Nicotine treatment did not elicit different responses between sexes in the FST. Our findings support the notion that liver TDO activity exhibits a strong association with behavioural measures of anxiety and depression in experimental models, but provide little evidence for sex differences in behavioural response to nicotine. The TDO-anxiety link may be underpinned by kynurenine metabolites as well as serotonin.

The importance of translationally evaluating steroid hormone contributions to substance use

Clinically, women appear to be more susceptible to certain aspects of substance use disorders (SUDs). The steroid hormones 17β-estradiol (E2) and progesterone (Pg) have been linked to women-specific drug behaviors. Here, we review clinical and preclinical studies investigating how cycling ovarian hormones affect nicotine-, cocaine-, and opioid-related behaviors. We also highlight gaps in the literature regarding how synthetic steroid hormone use may influence drug-related behaviors. In addition, we explore how E2 and Pg are known to interact in brain reward pathways and provide evidence of how these interactions may influence drug-related behaviors. The synthesis of this review demonstrates the critical need to study women-specific factors that may influence aspects of SUDs, which may play important roles in addiction processes in a sex-specific fashion. It is important to understand factors that impact women's health and may be key to moving the field forward toward more efficacious and individualized treatment strategies.

Acute nicotine exposure blocks aromatase in the limbic brain of healthy women: A [11C]cetrozole PET study

BACKGROUND

Of interest to women's mental health, a wealth of studies suggests sex differences in nicotine addiction and treatment response, but their psychoneuroendocrine underpinnings remain largely unknown. A pathway involving sex steroids could indeed be involved in the behavioural effects of nicotine, as it was found to inhibit aromatase in vitro and in vivo in rodents and non-human primates, respectively. Aromatase regulates the synthesis of oestrogens and, of relevance to addiction, is highly expressed in the limbic brain.

METHODS

The present study sought to investigate in vivo aromatase availability in relation to exposure to nicotine in healthy women. Structural magnetic resonance imaging and two [¹¹C]cetrozole positron emission tomography (PET) scans were performed to assess the availability of aromatase before and after administration of nicotine. Gonadal hormones and cotinine levels were measured. Given the region-specific expression of aromatase, a ROI-based approach was employed to assess changes in [¹¹C]cetrozole non-displaceable binding potential.

RESULTS

The highest availability of aromatase was found in the right and left thalamus. Upon nicotine exposure, [¹¹C]cetrozole binding in the thalamus was acutely decreased bilaterally (Cohen's d = -0.99). In line, cotinine levels were negatively associated with aromatase availability in the thalamus, although as non-significant trend.

CONCLUSIONS

These findings indicate acute blocking of aromatase availability by nicotine in the thalamic area. This suggests a new putative mechanism mediating the effects of nicotine on human behaviour, particularly relevant to sex differences in nicotine addiction.

Feasibility of Remotely Assessing Hormonal Contraceptive Use and Smoking-Related Symptomatology: Evidence from a Preliminary Prospective Cohort Study

Background

Half of women who smoke cigarettes also use hormonal contraceptives (HCs). Prior research suggests that variations in ovarian hormones may undermine smoking cessation efforts made by premenopausal women. However, clinical findings of these hormonal effects are inconsistent, potentially due to methodological limitations. The goal of this preliminary prospective cohort study is to determine the feasibility and acceptability of a fully remote protocol to longitudinally examine changes in smoking-related behavior and symptoms in relation to hormone use in women of reproductive age.

Methods

Eligible participants (n = 60) were biologically female, current age 18-35 years old, smokes ≥ 5 cigarettes/day, and classified into three groups: naturally-cycling (NC; n = 17), using a monophasic oral contraceptive (OC; n = 21), or using depot medroxyprogesterone acetate (DMPA; n = 22). Participants completed daily surveys and weekly dried blood spot collections.

Results

Overall, 92% (55/60) participants completed the study with 90% of daily surveys completed and 87% of participants collecting at least 5 of the 6 dried blood spot samples. Participants were "somewhat" (13%) or "extremely" (87%) likely to participate in the study again. Preliminary observations also suggested differences in self-reported cigarettes/day and premenstrual pain over time by study group.

Conclusions

This study outlines a fully remote protocol that may be used to clarify the relationships between hormonal contraceptive use and smoking-related outcomes over time. Preliminary results add to existing evidence that HC use may reduce relapse risk for premenopausal women.

Estradiol and progesterone in female reward-learning, addiction, and therapeutic interventions

Sex steroid hormones like estradiol (E2) and progesterone (P4) guide the sexual organization and activation of the developing brain and control female reproductive behavior throughout the lifecycle; importantly, these hormones modulate functional activity of not just the endocrine system, but most of the nervous system including the brain reward system. The effects of E2 and P4 can be seen in the processing of and memory for rewarding stimuli and in the development of compulsive reward-seeking behaviors like those seen in substance use disorders. Women are at increased risk of developing substance use disorders; however, the origins of this sex difference are not well understood and therapeutic interventions targeting ovarian hormones have produced conflicting results. This article reviews the contribution of the E2 and P4 in females to functional modulation of the brain reward system, their possible roles in origins of addiction vulnerability, and the development and treatment of compulsive reward-seeking behaviors.

Potential Disruption of Systemic Hormone Transport by Tobacco Alkaloids Using Computational Approaches

Tobacco/nicotine is one of the most toxic and addictive substances and continues to pose a significant threat to global public health. The harmful effects of smoking/nicotine affect every system in the human body. Nicotine has been associated with effects on endocrine homeostasis in humans such as the imbalance of gonadal steroid hormones, adrenal corticosteroid hormones, and thyroid hormones. The present study was conducted to characterize the structural binding interactions of nicotine and its three important metabolites, cotinine, trans-3'-hydroxycotinine, and 5'-hydroxycotinine, against circulatory hormone carrier proteins, i.e., sex-hormone-binding globulin (SHBG), corticosteroid-binding globulin (CBG), and thyroxine-binding globulin (TBG). Nicotine and its metabolites formed nonbonded contacts and/or hydrogen bonds with amino acid residues of the carrier proteins. For SHBG, Phe-67 and Met-139 were the most important amino acid residues for nicotine ligand binding showing the maximum number of interactions and maximum loss in ASA. For CBG, Trp-371 and Asn-264 were the most important amino acid residues, and for TBG, Ser-23, Leu-269, Lys-270, Asn-273, and Arg-381 were the most important amino acid residues. Most of the amino acid residues of carrier proteins interacting with nicotine ligands showed a commonality with the interacting residues for the native ligands of the proteins. Taken together, the results suggested that nicotine and its three metabolites competed with native ligands for binding to their carrier proteins. Thus, nicotine and its three metabolites may potentially interfere with the binding of testosterone, estradiol, cortisol, progesterone, thyroxine, and triiodothyronine to their carrier proteins and result in the disbalance of their transport and homeostasis in the blood circulation.

Progesterone Increases Nicotine Withdrawal and Anxiety in Male but Not Female Smokers During Brief Abstinence

INTRODUCTION

Although exogenous progesterone may hold promise as a treatment for nicotine use disorders, it is unclear whether it is similarly effective in males and females. This study examined the effects of progesterone on nicotine use disorder comprehensively using behavioral, psychological, and neural measures in male and female smokers exposed to brief abstinence.

AIMS AND METHODS

Thirty-three male and 33 female non-treatment-seeking smokers participated in a double-blind, randomized, placebo-controlled crossover study of 200 mg of progesterone or placebo daily over a four-day abstinence period. Smoking behavior and subjective effects of nicotine were assessed at baseline and after final drug administration. Nicotine withdrawal, smoking urges, mood states, and neural response to smoking cues were measured at baseline, after the first drug administration, and after the final drug administration.

RESULTS

No main effect of drug (progesterone vs. placebo) emerged for any outcome. Significant sex by drug interactions emerged for nicotine withdrawal (p = .020), perceived strength of nicotine (p = .040), and perceived bad effects of nicotine (p = .029). Males receiving progesterone reported worse nicotine withdrawal (p = .046) and a trend towards decreased bad effects of nicotine (p = .070). Males on progesterone also reported greater tension and anxiety relative to placebo (p = .021). Females on progesterone perceived nicotine's effects as being stronger relative to placebo (p = .046).

CONCLUSIONS

Progesterone causes sex-dependent effects on smoking-related outcomes during brief abstinence. Specifically, progesterone in males may increase rather than decrease nicotine withdrawal and negative affect during abstinence, potentially hindering efforts to quit smoking.

IMPLICATIONS

In male and female smokers undergoing a brief period of abstinence, we examined the effects of progesterone on smoking outcomes. While progesterone had limited effects in female smokers, in males, it worsened nicotine withdrawal and negative affect. Our findings emphasize the importance of analyzing sex differences in future studies examining progesterone as a potential treatment and suggest that progesterone in males could potentially exacerbate aspects of nicotine dependence.

CLINICALTRIALS.GOV REGISTRATION

NCT01954966. https://clinicaltrials.gov/ct2/show/NCT01954966.

Effect of progesterone administration in male and female smokers on nicotine withdrawal and neural response to smoking cues: role of progesterone conversion to allopregnanolone

BACKGROUND

Progesterone administration has therapeutic effects in tobacco use disorder (TUD), with females benefiting more than males. Conversion of progesterone to the neurosteroid allopregnanolone is hypothesized to partly underlie the therapeutic effects of progesterone; however, this has not been investigated clinically.

METHODS

Smokers (n = 18 males, n = 21 females) participated in a randomized, double-blind, placebo-controlled crossover study of 200 mg progesterone daily across 4 days of abstinence. The ratio of allopregnanolone:progesterone was analyzed in relationship to nicotine withdrawal, smoking urges, mood states, subjective nicotine effects, and neural response to smoking cues.

RESULTS

Allopregnanolone:progesterone ratio interacted with sex to predict withdrawal symptoms (p = 0.047), such that females with higher allopregnanolone:progesterone ratios reported lower withdrawal severity (b = - 0.98 [- 1.95, - 0.01]; p = 0.048). In addition, allopregnanolone:progesterone ratio interacted with sex to predict confusion (p = 0.014) and fatigue (p = 0.034), such that females with higher allopregnanolone:progesterone ratios reported less confusion (b = - 0.45 [- 0.78, - 0.12]; p = 0.008) and marginally lower fatigue (b = - 0.50 [- 1.03, 0.02]; p = 0.062. Irrespective of sex, higher ratios of allopregnanolone:progesterone were associated with stronger "good effects" of nicotine (b = 8.39 [2.58, 14.20]); p = 0.005) and weaker "bad effects" of nicotine (b = - 7.13 [- 13.53, - 0.73]; p = 0.029).

CONCLUSIONS

Conversion of progesterone to allopregnanolone correlated with smoking-related outcomes in both sex-dependent and sex-independent ways. Sex-dependent effects suggest that conversion of progesterone to allopregnanolone may contribute to greater therapeutic benefits in females but not males with TUD. Trial registration Clinicaltrials.gov registration, retrospectively registered: NCT01954966; https://clinicaltrials.gov/ct2/show/NCT01954966 \.

Sex-Dependent Alterations of Regional Homogeneity in Cigarette Smokers

Biological sex may play a large role in cigarette use and cessation outcomes and neuroimaging studies have demonstrated that cigarette smoking is associated with sex-related differences in brain structure and function. However, less is known about sex-specific alterations in spontaneous brain activity in cigarette smokers. In this study, we investigated the sex-related effects of cigarette smoking on local spontaneous brain activity using regional homogeneity (ReHo) based on resting-state fMRI. Fifty-six smokers (24 females) and sixty-three (25 females) healthy non-smoking controls were recruited. Whole-brain voxelwise 2-way analysis of covariance of ReHo was performed to detect brain regions with sex-dependent alterations on the spontaneous brain activity. Compared to non-smokers, smokers exhibited significant ReHo differences in several brain regions, including the right medial orbitofrontal cortex extended to the ventral striatum/amygdala/parahippocampus, left precuneus, and bilateral cerebellum crus. Smoking and sex interaction analysis revealed that male smokers showed significantly lower ReHo in the right ventral striatum, left cerebellum crus1, and left fusiform gyrus compared to male non-smokers, whereas there are no significant differences between female smokers and non-smokers. Furthermore, the ReHo within the left cerebellum crus1 was negatively correlated with craving scores in male smokers but not in female smokers. Such sex-dependent differences in spontaneous brain activity lays a foundation for further understanding the neural pathophysiology of sex-specific effects of nicotine addiction and promoting more effective health management of quitting smoking.

The Effects of Menstrual Cycle Hormones on Responses to Varenicline and Naltrexone Among Female Heavy Drinking Smokers

Aims

Women often experience poorer smoking cessation outcomes in comparison to men. Menstrual cycle phase and sex hormones may influence smoking behavior and alter response to opioid antagonist medications. Less is known about the effects of sex hormones in response to pharmacotherapy for female heavy drinking smokers.

Methods

This study is a secondary analysis of premenopausal female heavy drinking smokers who completed a 12-week randomized clinical trial comparing varenicline plus placebo versus varenicline plus naltrexone for smoking cessation and drinking reduction. Participants (n = 26; total observations = 66) provided saliva samples for assays of progesterone (P4) and estradiol (E2) post-randomization at Weeks 4, 8 and 12. We examined the effects of P4/E2 ratio and medication on smoking and drinking outcomes.

Results

For drinking outcomes, there was a significant interaction for percent days abstinent (b = 0.017, P = 0.05), suggesting that greater P4/E2 ratio is associated with greater percent days abstinent for women assigned to the varenicline plus naltrexone condition. There were no interaction effects for the remaining drinking outcomes (P’s ≥ 0.12). Results found no significant interaction effect of P4/E2 ratio and medication on smoking abstinence (P = 0.19).

Conclusion

Our results imply that when women show a greater P4/E2 ratio, typically observed during the luteal phase of the menstrual cycle, they experience an added benefit of naltrexone, versus placebo, for drinking outcomes as shown by greater percent days abstinent. Additional studies in larger samples are warranted as sex hormones offer important information above and beyond comparing women versus men.

Natural and synthetic estrogens specifically alter nicotine demand and cue-induced nicotine seeking in female rats

Women have more difficulty maintaining smoking cessation than men, and experience greater withdrawal symptomatology as well as higher prevalence of relapse. Further, currently available treatments for smoking cessation, such as the nicotine patch and varenicline, have been shown to be less effective in women. Fluctuations in ovarian hormones across the menstrual cycle can affect craving and smoking relapse propensity. In addition, many women who smoke use some form of oral contraceptives, which most often contain ethinyl estradiol (EE), a synthetic, orally bio-available estrogen that is currently prescribed to women chronically and has been shown to alter smoking reward in women. The current study examined the impact of 17β-estradiol (E2), the prominent endogenous form of the steroid hormone estrogen, as well as EE, on nicotine self-administration, demand, and reinstatement following ovariectomy (OVX) or sham surgery. OVX vehicle-treated female rats consumed less nicotine, had lower intensity of demand, and reinstated less compared to sham vehicle-treated female rats. OVX-E2 and OVX-EE treatment groups showed a rebound of nicotine intake later in training, and Q₀ levels of consumption were partially rescued in both groups. Further, E2 but not EE reversed the abolishment of reinstated nicotine seeking induced by OVX. Taken together, these results demonstrate that natural and synthetic estrogens play a critical role in mediating the neurobehavioral effects of nicotine, and future studies are essential for our understanding of how synthetic hormones contained within oral contraceptives interact with smoking.

Use patterns of cigarettes and alternative tobacco products and socioeconomic correlates in Hong Kong secondary school students

Smoking is a major cause of health inequities. However, sociodemographic differences in adolescent tobacco use are unclear. In a territory-wide school-based anonymous survey in 2018/19, we investigated tobacco use and sociodemographic correlates in 33,991 students (mean age 14.8 ± 1.9 years) in Hong Kong. Tobacco use prevalence and current-ever use ratios by sociodemographic factors were calculated. Generalised linear mixed models were used in association analyses. Current use was highest for cigarettes (3.2%), closely followed by alternative tobacco products (3.0%). Current-ever use ratios were highest for heated tobacco products (HTPs, 0.60), followed by nicotine e-cigarettes (0.52), waterpipe (0.51), and cigarettes (0.35). Use prevalence and current-ever use ratios of all products showed curvilinear relations with perceived family affluence (P values < 0.01), being highest in the richest families. Tobacco use was also associated with more senior grades, the lowest parental education, and boys, but current-ever use ratios of HTPs and waterpipe were higher in girls (P values < 0.05). The results suggested that adolescent ever users of nicotine-containing alternative tobacco products were more likely to keep using them than cigarettes, and the richest adolescents were at the highest risks of tobacco use. Diverse tobacco control measures are needed to improve health equity, especially on alternative tobacco products.

Addictive behaviors across the menstrual cycle: a systematic review

Research examining relations between menstrual cycle phase and female addictive behaviors is accumulating. Theories suggest addictive behaviors may increase during specific phases of the menstrual cycle resulting from cyclical fluctuations in hormones and affect. In line with self-medication theory, we predicted that addictive behaviors would increase premenstrually and menstrually, phases marked by elevations in negative affect, relative to the follicular and luteal phases. We also hypothesized, coinciding with reward-sensitivity theory, that addictive behaviors may increase during ovulation, a phase characterized by increased positive affect, compared to the same phases. This systematic review summarizes extant literature examining the menstrual cycle phase-addictive behavior relationship and underlying motivations. Articles pertaining to menstrual cycle phase and addictive behaviors within the PsycINFO, CINAL, and PubMED databases were screened to determine eligibility following PRISMA guidelines (n = 1568). Thirty-four articles examining alcohol use, cannabis use, nicotine use, caffeine use, and gambling behavior across menstrual cycle phase met inclusion criteria. Consistent with self-medication theory, strong evidence indicated that nicotine use increased premenstrually and menstrually. Other factors increasing both nicotine and alcohol use premenstrually and menstrually include having a premenstrual dysphoric disorder diagnosis or having premenstrual syndrome. Motivations for using alcohol and nicotine may too vary by menstrual cycle phase. Results were less consistent or understudied for other addictive behaviors and thus conclusions cannot be drawn. Menstrual cycle phase appears to be a female-specific factor affecting some addictive behaviors, particularly nicotine use, and should be considered when conducting addictive behavior research or clinical interventions for reproductive-aged females with addictive disorders.

Sex-specific effects of cigarette smoking on caudate and amygdala volume and resting-state functional connectivity

Recent studies have demonstrated sex-specific differences in etiology, course and brain dysfunction that are associated with cigarette smoking. However, little is known about sex-specific differences in subcortical structure and function. In this study, structural and resting-state functional magnetic resonance imaging (fMRI) data were collected from 60 cigarette smokers (25 females) and 67 nonsmokers (28 females). The structural MRI was applied to identify deficits in sex-specific subcortical volume. Using resting-state fMRI, sex-related alterations in resting-state functional connectivity (rsFC) were investigated in subcortical nuclei with volume deficits as seed regions. Compared to nonsmokers, male but not female smokers demonstrated a significantly smaller volume in the left caudate, while female but not male smokers showed a smaller volume in the right amygdala. Resting-state FC analysis revealed that male but not female smokers had increased rsFC between the left caudate and the left prefrontal cortex but decreased rsFC within the bilateral caudate and between the right amygdala and right orbitofrontal cortex (OFC). Furthermore, the right amygdala volume was negatively correlated with the impulsivity score in female but not male smokers. The rsFC of the right amygdala-OFC circuit was negatively associated with the craving score in male but not female smokers. These findings indicate that cigarette smoking may have differential effects on the caudate and amygdala volumes as well as rsFC between men and women, contributing to our knowledge of sex-specific effects of nicotine addiction. Such sex-specific differences in subcortical structure and function may provide a methodological framework for the development of sex-specific relapse prevention therapies.

Sex differences in progestogen- and androgen-derived neurosteroids in vulnerability to alcohol and stress-related disorders

Stress and trauma exposure disturbs stress regulation systems and thus increases the vulnerability for stress-related disorders which are characterized by negative affect, including major depressive disorder, anxiety disorders and posttraumatic stress disorder. Similarly, stress and trauma exposure results in increased vulnerability to problematic alcohol use and alcohol use disorder, especially among women, who are more likely to drink to cope with negative affect than their male counterparts. Given these associations, the relationship between stress-related disorders and alcohol use is generally stronger among women leading to complex comorbidities across these disorders and alcohol misuse. This review highlights the therapeutic potential for progestogen- and androgen-derived neurosteroids, which affect both stress- and alcohol-related disorders, to target the overlapping symptoms related to negative affect. This article is part of the special issue on 'Vulnerabilities to Substance Abuse.'

Effect of exogenous progesterone administration on smoking topography

INTRODUCTION

Progesterone has been implicated as protective against drug taking behaviors, including combustible cigarettes. While prior research indicates higher endogenous progesterone levels are associated with a reduction in smoking intensity (as measured by smoking topography), it is unknown if exogenous delivery of progesterone may have the same effect.

METHODS

This double-blind, counterbalanced, cross-over randomized trial enrolled women between the ages of 18 and 40 who smoked at least five cigarettes per day and were currently using oral contraceptives. After overnight abstinence participants attended two topography lab sessions. One lab session was conducted during progesterone (200 mg twice per day) treatment and the other was during placebo treatment. Analyses included linear mixed effect models to examine the effect of exogenous progesterone administration and endogenous progesterone values on topography outcomes.

RESULTS

Participants (n = 43) were 23.8 (standard deviation [SD] ± 4.5) years old, smoked 10.5 (SD ± 3.7) cigarettes per day. Compared to placebo administration, progesterone administration reduced cumulative puff volume by 300 mL (95% confidence interval [CI]: -536, -65; p-value = 0.01) with additional trends indicating possible reductions in the number of puffs, average puff volume, and average flow. There were no significant effects of endogenous progesterone on smoking topography outcomes.

CONCLUSIONS

Progesterone administration has the potential to reduce smoking intensity after overnight abstinence in women of reproductive age. Additional research is needed to explore how this may relate to smoking cessation outcomes in women of reproductive age.

Sex- and age-dependent differences in nicotine susceptibility evoked by developmental exposure to tobacco smoke and/or ethanol in mice

Either tobacco smoking or alcohol consumption during pregnancy sex-selectively increases susceptibility to drugs of abuse later in life. Considering that pregnant smoking women are frequently intermittent consumers of alcoholic beverages, here, we investigated whether a short-term ethanol exposure restricted to the brain growth spurt period when combined with chronic developmental exposure to tobacco smoke aggravates susceptibility to nicotine in adolescent and adult mice. Swiss male and female mice were exposed to tobacco smoke (SMK; research cigarettes 3R4F, whole-body exposure, 8 h/daily) or ambient air during the gestational period and until the tenth postnatal day (PN). Ethanol (ETOH, 2 g/Kg, 25%, i.p.) or saline was injected in the pups every other day from PN2 to PN10. There were no significant differences in cotinine (nicotine metabolite) and ethanol serum levels among SMK, ETOH and SMK + ETOH groups. During adolescence (PN30) and adulthood (PN90), nicotine (NIC, 0.5 mg/Kg) susceptibility was evaluated in the conditioned place preference and open field tests. NIC impact was more evident in females: SMK, ETOH and SMK + ETOH adolescent females were equally more susceptible to nicotine-induced place preference than control animals. At adulthood, SMK and SMK + ETOH adult females exhibited a nicotine-evoked hyperlocomotor profile in the open field, with a stronger effect in the SMK + ETOH group. Our results indicate that ethanol exposure during the brain growth spurt, when combined to developmental exposure to tobacco smoke, increases nicotine susceptibility with stronger effects in adult females. This result represents a worsened outcome from the early developmental dual exposure and may predispose nicotine use/abuse later in life.

Administration of Exogenous Hormones and the Implications for Cigarette Smoking-Related Behaviors

PURPOSE OF REVIEW

Preclinical evidence indicates progesterone and estrogen influence drug-taking behaviors, including nicotine/tobacco. However, clinical research on this relationship is less clear. This lack of clarity may be due to measuring naturally occurring endogenous hormones to examine this relationship, which introduces substantial error. Therefore, the goal of this review is to examine the link between the delivery of exogenous hormones and cigarette smoking-related behavior.

RECENT FINDINGS

Exogenous progesterone may have favorable effects on cognition, symptomatology, consumption, and smoking cessation. Hormonal replacement therapy does not have a clear relationship with smoking-related behaviors. Oral contraceptive use may have adverse effects on stress response, nicotine metabolism, and symptomatology. Additional research is needed to explore how the administration of exogenous hormones may (a) strengthen research methodology on this topic, (b) enhance our understanding of the role of progesterone/estrogen on smoking-related behaviors, and (c) improve smoking cessation outcomes.

Hormonal responses in gambling versus alcohol abuse: A review of human studies

The endocrine system plays an essential role in communication between various organs of the body to maintain homeostasis. Both substance use disorders (SUDs) and non-substance abuse disrupt this system and lead to hormonal dysregulations. Here, we focus on the comparison between the function of the endocrine system in gambling disorders and alcohol addiction to understand the commonalities and differences in their neurobiological and psychological underpinnings. We review human research to compare findings on gambling addiction and alcohol dependence pertaining to the dynamic interplay between testosterone and cortisol. Understanding and classifying similarities in hormonal responses between behavioural addiction and SUDs may facilitate development of treatments and therapeutic interventions across different types of addictive disorders, while describing differences may shed light on therapeutic interventions for specific disorders. Although research on gambling addiction is in its infancy, such evaluation may still have a positive effect for addiction research, thereby stimulating discovery of "crossover" pharmacotherapies with benefits for both SUDs and nonsubstance addictions.

Response to nicotine following overnight smoking abstinence during short-term progesterone treatment in women

Preclinical and clinical literature suggest that sex hormones impact tobacco use behaviors in women. The goal of this double-blind crossover laboratory study was to examine the effect of oral exogenous progesterone (200 mg twice per day) versus placebo on nicotine response using measures of motor speed and cognitive function in women following overnight smoking abstinence. We hypothesized that increased progesterone would blunt the nicotine response whereby producing less change in motor speed and cognition in response to nicotine exposure. Female smokers, age 18-35, were randomized to participate in two 9-day crossover testing weeks. Participants completed a lab session following overnight abstinence where they were administered nicotine nasal spray and asked to complete measures of immediate memory (IMT), delayed memory (DMT), word recall (WR), and finger tapping speed (FT). After the first 9-day testing week, participants resumed smoking and returned the following month to complete the identical lab session in the crossover condition. Forty-seven women were included in this analysis (n = 47). We found no differences in the magnitude of response for IMT, DMT, and WR between conditions. For FT, women had a blunted response to nicotine during the placebo condition. When examining the association between hormone levels and relative performance, we found increases in DMT, WR, and FT but decreases in IMT during the progesterone condition. We observed differences between progesterone versus placebo in relative change in some measures of nicotine response following overnight abstinence. Future studies are needed to further characterize this response. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Nicotine Effects, Body Weight Concerns and Smoking: A Literature Review

How people become addicted to cigarette smoking and remain addicted despite repeated attempts to quit requires piecing together a rather complex puzzle. The present review contextualizes the role of nicotine and smoking sensory stimulation on maintaining smoking, describes nicotine's effects on feeding behavior and body weight, and explores the impact of smoking outcome expectancies, including the belief that nicotine suppresses appetite and body weight, on the decision to smoke or vape (use of e-cigarettes). The analysis concludes with a review of rat models of human nicotine intake that attempt to isolate the effects of nicotine on appetite and weight gain. Animal research replicates with relative closeness phenomena observed in smokers, but the rat model falls short of replicating the long-term weight gain observed post-smoking cessation.

Influences of the Menstrual Phase on Cortisol Response to Stress in Nicotine Dependent Women: A Preliminary Examination

INTRODUCTION

Evidence indicates that menstrual cycle phase plays a role in smoking withdrawal symptoms and craving. Stress increases these symptoms. Whether the stress regulatory mechanism is associated with menstrual phase and withdrawal symptoms is not well understood.

METHODS

Thirty-seven female smokers and 16 female nonsmokers were asked to complete a laboratory session. In each group, approximately half of the participants were tested when they were in the follicular phase and the other half was tested in the luteal phase. The session included resting baseline, stress, and recovery periods. Saliva samples for the measurement of cortisol and subjective measures of craving and withdrawal symptoms were collected at the end of each period.

RESULTS

A series of repeated measures analysis of covariance found a significant smoking group × menstrual phase × sampling time interaction in cortisol levels (p < .05). Follow-up analyses indicated a reduced cortisol stress response in the luteal group relative to the follicular group in smokers (p < .02). This difference was not found in nonsmokers.

CONCLUSIONS

Menstrual cycle phase is related to hormonal stress response and smoking withdrawal symptomatology.

IMPLICATIONS

We show influences of the menstrual cycle phase on stress response among smokers. This is demonstrated by a reduced cortisol response to stress in the luteal group relative to the follicular group among smokers. This menstrual phase difference was not found in nonsmokers.

Effect of exogenous progesterone administration on cigarette smoking-related symptomology in oral contraceptive users who smoke

Cigarette smoking-related symptomatology (e.g., craving; SRS) is linked to relapse after a quit attempt. SRS varies by menstrual phase, possibly due to variations in sex hormones (e.g., progesterone), though much of the research to-date has relied on observations from the menstrual cycle acting as a proxy for hormone levels. The goal of this study was to examine the effect of exogenous progesterone on SRS during ad libitum smoking and following overnight abstinence. Oral contraceptive users who smoked completed two 9-day crossover testing periods (7 days of ad libitum smoking and 2 days following overnight abstinence) while taking double-blind active/placebo exogenous progesterone. Participants completed questionnaires to measure SRS. The effect of exogenous progesterone and endogenous hormones (progesterone, estradiol, and progesterone-to-estradiol [P/E₂] ratio) on SRS was assessed with paired t-tests and linear mixed effect models. Participants (n = 53) were, on average, 24 years old and smoked 11 cigarettes per day. During ad libitum smoking, a doubling of the P/E₂ ratio was associated with 0.09 points lower anticipated relief from negative affect (95% confidence interval [CI]: 0.03-0.15 points lower; p = 0.008) and 0.11 points lower psychological reward (95% CI: 0.03-0.18 points lower; p = 0.006). After correction for multiple testing, these associations were not statistically significant: anticipated relief from negative effect (p = 0.10) and psychological reward (p = 0.09). No other significant associations were observed. Although substantial previous literature indicates that progesterone influences SRS, exogenous progesterone administration did not alter SRS here. Additional research is needed to elucidate alternative mechanisms involved in menstrual phase effects on SRS.

Variability in nicotine conditioned place preference and stress-induced reinstatement in mice: Effects of sex, initial chamber preference, and guanfacine

Relapse to smoking occurs at higher rates in women compared with men, especially when triggered by stress. Studies suggest that sex-specific interactions between nicotine reward and stress contribute to these sex differences. Accordingly, novel treatment options targeting stress pathways, such as guanfacine, an α2-adrenergic receptor agonist, may provide sex-sensitive therapeutic effects. Preclinical studies are critical for elucidating neurobiological mechanisms of stress-induced relapse and potential therapies, but rodent models of nicotine addiction are often hindered by large behavioral variability. In this study, we used nicotine conditioned place preference to investigate stress-induced reinstatement of nicotine preference in male and female mice, and the effects of guanfacine on this behavior. Our results showed that overall, nicotine induced significant place preference acquisition and swim stress-induced reinstatement in both male and female mice, but with different nicotine dose-response patterns. In addition, we explored the variability in nicotine-dependent behaviors with median split analyses and found that initial chamber preference in each sex differentially accounted for variability in stress-induced reinstatement. In groups that showed significant stress-induced reinstatement, pretreatment with guanfacine attenuated this behavior. Finally, we evaluated neuronal activation by Arc immunoreactivity in the infralimbic cortex, prelimbic cortex, anterior insula, basolateral amygdala, lateral central amygdala and nucleus accumbens core and shell. Guanfacine induced sex-dependent changes in Arc immunoreactivity in the infralimbic cortex and anterior insula. This study demonstrates sex-dependent relationships between initial chamber preference and stress-induced reinstatement of nicotine conditioned place preference, and the effects of guanfacine on both behavior and neurobiological mechanisms.

Randomized Clinical Trials Investigating Innovative Interventions for Smoking Cessation in the Last Decade

Every year, billions of dollars are spent treating smoking and related conditions, yet smoking-related morbidity and mortality continue to rise. There are currently only three FDA-approved medications for smoking cessation: nicotine replacement therapy, bupropion, and varenicline. Although these medications increase abstinence rates, most individuals relapse following treatment. This chapter reviews clinical trials published within the past 10 years investigating novel smoking cessation pharmacotherapies. Among these pharmacotherapies, some showed promising results, such as cytisine and endocannabinoid modulators, whereas others failed to produce significant effects. More research is needed to develop drugs that produce higher rates of long-term abstinence and to determine which subgroups of patients benefit from a given treatment.

N-acetylcysteine yields sex-specific efficacy for cue-induced reinstatement of nicotine seeking

Women report greater craving during certain phases of the menstrual cycle. As well, research indicates that pharmacotherapies for smoking may be less efficacious in women compared with men, which may be due to interactions with natural fluctuations in ovarian hormone levels. N-Acetylcysteine (NAC) is a glutamatergic compound that has shown some efficacy in treating substance use disorders and aids in the prevention of relapse. However, it is unclear whether NAC has sex-specific effectiveness for nicotine relapse treatment. Given that NAC has shown promise to reduce nicotine reinstatement in preclinical models using male rats, the exploration of potential sex differences in the efficacy of NAC is warranted. Using a rat model, we first investigated the ability of NAC treatment (100 mg/kg, ip) during nicotine withdrawal with extinction training to reduce cue-induced nicotine seeking in male and female rats. Next, we assessed whether NAC's effects were estrous cycle-dependent for female rats. Results show that following NAC treatment during extinction, reinstatement of nicotine seeking was significantly decreased in males but not females, indicating a sex-specific effect of NAC. Furthermore, for females, both vehicle- and NAC-treated groups significantly reinstated nicotine-seeking behavior compared with extinction, regardless of estrous cycle phase. These results suggest that NAC is inefficacious in reducing nicotine relapse in females regardless of estrous cycle phase at the dose evaluated here. These collective findings could have important clinical implications for use and efficacy of NAC as a pharmacotherapy for freely cycling women smokers.

Sex and the dopaminergic system: Insights from addiction studies

Sex differences are present in psychiatric disorders associated with disrupted dopamine function, and thus, sex differences in dopamine neurobiology may underlie these clinical disparities. In this chapter, we review sex differences in the dopaminergic system with a focus on substance use disorders, especially tobacco smoking, as our exemplar disorder. This chapter is organized into five sections describing sex differences in the dopaminergic system: (1) neurobiology, (2) role of sex hormones, (3) genetic underpinnings, (4) cognitive function, and (5) influence on addiction. In each section, we provide an overview of the topic area, summarize sex differences identified to date, highlight addiction research, especially clinical neuroimaging studies, and suggest avenues for future research.

Association Between Smoking and Premenstrual Syndrome: A Meta-Analysis

Results of basic science studies demonstrate shared actions of endogenous neuroactive steroid hormones and drugs of abuse on neurotransmission. As such, premenstrual syndrome (PMS) may be associated with smoking, however, results from studies examining this relationship have been mixed. Following PRISMA guidelines, we extracted unique studies examining the relationship between smoking and PMS. We used the escalc () function in R to compute the log odds ratios and corresponding sampling variance for each study. We based quality assessment on the nature of PMS diagnosis and smoking estimation, confounding adjustment, participation rate, and a priori specification of target population. Our final sample included 13 studies, involving 25,828 study participants. Smoking was associated with an increased risk for PMS [OR = 1.56 (95% CI: 1.25-1.93), p < 0.0001]. Stratified by diagnosis, the effect size estimate was higher for Premenstrual Dysphoric Disorder (PMDD) [OR = 3.15 (95% CI: 2.20-4.52), p < 0.0001] than for PMS [OR = 1.27 (95% CI: 1.16-1.39), p < 0.0001]. We review some of the basic mechanisms for the observed association between smoking and PMS. Given nicotine's rewarding effects, increased smoking behavior may be a mechanism to alleviate affective symptoms of PMS. However, smoking may lead to worsening of PMS symptoms because nicotine has effects on neurocircuitry that increases susceptibility to environmental stressors. Indeed, prior evidence shows that the hypothalamic-pituitary-adrenal (HPA) axis is already sub-optimal in PMS, hence, smoking likely further deteriorates it. Combined, this complicates the clinical course for the treatment of both PMS and Tobacco Use Disorder in this population.

Differences in mechanisms underlying reinstatement of cigarette smoke extract- and nicotine-seeking behavior in rats

Despite extensive research, current therapies for smoking cessation are largely ineffective at maintaining abstinence for more than a year. Whereas most preclinical studies use nicotine alone, the goal of the present study was to evaluate whether inclusion of non-nicotine tobacco constituents provides better face validity for the development of new pharmacological therapies for smoking cessation. Here, we trained adult male rats to self-administer nicotine alone or cigarette smoke extract (CSE), which contains nicotine and other aqueous constituents of cigarette smoke. After stable self-administration behavior was established, animals underwent extinction training followed by drug and cue primed reinstatement testing. We show that animals that self-administered CSE had significant reinstatement in all drug and drug + cue stimulus conditions whereas animals that self-administered nicotine only showed significant reinstatement in the drug + cue conditions. AT-1001, an α3β4 nicotinic acetylcholine receptor (nAChR) functional antagonist, attenuated drug + cue-primed reinstatement of both CSE- and nicotine-seeking behavior. However, AT-1001 was less potent in blocking drug-primed reinstatement in animals that had self-administered CSE than in those that had self-administered nicotine alone. This was the case even when nicotine was used to prime reinstatement in animals that had self-administered CSE, suggesting that prior CSE exposure had altered the functional role of α3β4-containing nAChRs in drug-seeking behavior. These findings confirm the importance of non-nicotine tobacco constituents and α3β4* nAChRs in cue- and nicotine-primed craving. They also suggest that tests using CSE may be more valid models to study tobacco dependence than use of nicotine alone.

Subjective response to intranasal nicotine administration in oral contraceptive users and naturally-cycling women

INTRODUCTION

Approximately half of premenopausal women who smoke cigarettes also use hormonal contraceptives, with most using oral contraceptives (OCs). While research on the effects of endogenous hormones on smoking-related outcomes continues to expand, little is known about the influence of OCs on similar outcomes. We sought to explore differences in the subjective response to nicotine by OC use after stratifying by testing condition (e.g., smoking status).

METHODS

Participants were regular (≥5 cigarettes/day) smokers, classified into OC and naturally cycling (NC) groups. All participants completed four total lab sessions by smoking status (ad libitum smoking, acute smoking abstinence) and anticipated progesterone level (low progesterone week (LPW), high progesterone week (HPW)). Each lab session included self-administration of intranasal nicotine (Time 0 min), assessment of subjective response via the Subjective State Scale (-30 and + 5 min).

RESULTS

Compared to the NC group (n = 28), the OC group (n = 14) was younger (26.2 ± 1.1 versus 24.2 ± 1.1; p < 0.001) and had a lower Fagerström Test for Nicotine Dependence score (3.4 ± 0.5 versus 2.6 ± 0.5; p = 0.011). Progesterone-to-estradiol ratios varied significantly by group at three of the four time points (p < 0.05). During ad libitum smoking, the OC group had significantly lower craving after nicotine administration than the NC group (1.93 ± 0.33 versus 2.89 ± 0.23; p = 0.024). No other significant differences in subjective response were identified.

CONCLUSIONS

Despite significantly different hormone levels, group differences in subjective response to nicotine were relatively few. Additional research is needed to elucidate the mechanisms involved in these observations, as well as explore how they may influence cessation in women.

Commentary on Tosun et al. (2019): Dynamic changes in sex hormones and smoking cessation

There is growing evidence suggesting that exogenous progesterone may improve smoking cessation outcomes among women. We hypothesize that exogenous progesterone administration can result in stable progesterone levels, and that it is the absence of dynamic hormone change that may lead to improved smoking cessation outcomes.

Exogenous progesterone for smoking cessation in men and women: a pilot double-blind, placebo-controlled randomized clinical trial

BACKGROUND AND AIMS

In some clinical studies men and women have been found to differ in their ability to quit smoking, perhaps as a result of progesterone. The primary aim of this study was to provide a preliminary test of whether progesterone (PRO), compared with placebo (PBO), was more effective for smoking cessation in men and women.

DESIGN

Pilot double-blind, placebo-controlled randomized clinical trial.

SETTING

Minneapolis/St Paul metro area, Minnesota, USA.

PARTICIPANTS

A total of 216 participants were randomized, including 113 men (18-60 years; PRO = 56, PBO = 57) and 103 women (18-50 years, pre-menopausal with self-reported regular menstrual cycles; PRO = 51, PBO = 52).

INTERVENTION

Participants were randomized (1 : 1 within sex group) to either PRO (200 mg twice daily) or PBO. Participants were assigned a quit date approximately 7 days after starting medication (luteal phase for women) and were followed for 12 weeks to assess relapse.

MEASUREMENTS

The primary outcome was self-reported 7-day point prevalence abstinence (PPA) at week 4. Secondary outcomes included 7-day PPA at weeks 8 and 12, prolonged abstinence, continuous abstinence, urine cotinine < 50 ng/ml, expired carbon monoxide ≤ 5 parts per million (p.p.m.) and days to relapse.

FINDINGS

There was a significant difference in 7-day PPA at week 4 among women [PRO: 18 (35.3%) versus PBO: 9 (17.3%), odds ratio (OR) = 2.61, 95% confidence interval (CI) = 1.04, 6.54, P = 0.041], but not among men [PRO: 13 (23.2%) versus PBO: 12 (21.1%), 1.13 (0.47, 2.76), P = 0.782]. There was some evidence that PRO delayed relapse in women (days to relapse; PRO: 20.5 ± 29.6 versus PBO: 14.3 ± 26.8, P = 0.03) but not in men (PRO: 13.4 ± 25.9 versus PBO: 13.3 ± 23.8, P = 0.69).

CONCLUSIONS

Oral micronized progesterone may aid smoking cessation in women.

Smoking-related symptomatology in pregnant smokers during ad libitum smoking and following overnight smoking abstinence

Objective

Current literature suggests there may be a relationship between sex hormones, which dramatically increase during pregnancy, and nicotine use behaviors. We hypothesized that higher progesterone and progesterone:estradiol ratio (P/E₂) would be associated with less smoking-related symptomatology (SRS), better mood and fewer cigarettes smoked per day (CPD) during ad libitum smoking and following overnight abstinence in pregnant women. Associations between SRS, mood, smoking behavior and sex hormones were estimated using multiple linear regression with adjustment for CPD and pregnancy trimester.

Results

There were 35 second trimester and 42 third trimester participants. Participants mean age was 26.2 (SD: 4.1), they smoked 11.3 CPD (SD: 4.4) and the mean nicotine dependence score was 4.94 (SD: 1.98). There were no statistically significant associations between progesterone levels, estradiol levels, or the P/E₂ ratio and SRS or mood measures during ad libitum smoking or following overnight abstinence in this sample of pregnant women. Similarly, there were no associations between sex hormone levels and number of CPD smoked during the ad libitum period. Contrary to our hypothesis, we found no significant associations between sex hormones and SRS, mood or smoking behavior in this sample of pregnant women.

Trial registration ClinicalTrials.gov (NCT01811225), December 6, 2012

Oral Contraceptives and Cigarette Smoking: A Review of the Literature and Future Directions

INTRODUCTION

Evidence continues to mount indicating that endogenous sex hormones (eg, progesterone and estradiol) play a significant role in smoking-related outcomes. Although approximately one out of four premenopausal smokers use oral contraceptives (OCs), which significantly alter progesterone and estradiol levels, relatively little is known about how OCs may influence smoking-related outcomes. Thus, the goal of this review article is to describe the state of the literature and offer recommendations for future directions.

METHODS

In March 2017, we searched seven databases, with a restriction to articles written in English, using the following keywords: nicotine, smoker(s), smoking, tobacco, cigarettes, abstinence, withdrawal, and craving(s). We did not restrict on the publication date, type, or study design.

RESULTS

A total of 13 studies were identified. Three studies indicated faster nicotine metabolism in OC users compared to nonusers. Five of six laboratory studies that examined physiological stress response noted heightened response in OC users compared to nonusers. Three studies examined cessation-related symptomatology (eg, craving) with mixed results. One cross-sectional study observed greater odds of current smoking among OC users, and no studies have explored the relationship between OC use and cessation outcomes.

CONCLUSIONS

Relatively few studies were identified on the role of OCs in smoking-related outcomes. Future work could explore the relationship between OC use and mood, stress, weight gain, and brain function/connectivity, as well as cessation outcomes. Understanding the role of OC use in these areas may lead to the development of novel smoking cessation interventions for premenopausal women.

IMPLICATIONS

This is the first review of the relationship between oral contraceptives (OCs) and smoking-related outcomes. The existing literature suggests that the use of OCs is related to increased nicotine metabolism and physiological stress response. However, the relationship between OC use and smoking-related symptoms (eg, craving) is mixed. Further, no published data were available on OC use and smoking cessation outcomes. Therefore, we recommend additional research be conducted to characterize the relationship between OC use and smoking cessation outcomes, perhaps as a function of the effect of OC use on mood, stress, weight gain, and brain function/connectivity.

Progesterone Is Important for Transgender Women's Therapy-Applying Evidence for the Benefits of Progesterone in Ciswomen

BACKGROUND

Although the 2017 Endocrine Society Guidelines for gender dysphoria stipulated that cross-sex hormone therapy (CHT) achieve gonadal steroid levels equivalent to those of a cisperson of the chosen sex, for transgender women (male-to-female gender dysphoria), current gonadal therapy is usually estradiol. Accumulated evidence indicates that normally ovulatory menstrual cycles are necessary for ciswomen's current fertility, as well as for later-life bone and cardiovascular health and the prevention of breast and endometrial cancers.

EVIDENCE ACQUISITION

Extensive past clinical experience with transgender women's CHT using estradiol/estrogen combined with progesterone/medroxyprogesterone and pioneering the addition of spironolactone. Comprehensive progesterone physiology research plus a brief review of transgender women's literature to assess current therapy and clinical outcomes, including morbidity and mortality.

PURPOSE

To emphasize that both ovarian hormones, progesterone as well as estradiol, are theoretically and clinically important for optimal transgender women's CHT.

EVIDENCE SYNTHESIS

It is important to add progesterone to estradiol and an antiandrogen in transgender women's CHT. Progesterone may add the following: (i) more rapid feminization, (ii) decreased endogenous testosterone production, (iii) optimal breast maturation to Tanner stages 4/5, (iv) increased bone formation, (v) improved sleep and vasomotor symptom control, and (vi) cardiovascular health benefits.

CONCLUSIONS

Evidence has accrued that normal progesterone (and ovulation), as well as physiological estradiol levels, is necessary during ciswomen's premenopausal menstrual cycles for current fertility and long-term health; transgender women deserve progesterone therapy and similar potential physiological benefits.

Sex differences in stress-related alcohol use

Rates of alcohol use disorder (AUD) have increased in women by 84% over the past ten years relative to a 35% increase in men. This substantive increase in female drinking is alarming given that women experience greater alcohol-related health consequences compared to men. Stress is strongly associated with all phases of alcohol addiction, including drinking initiation, maintenance, and relapse for both women and men, but plays an especially critical role for women. The purpose of the present narrative review is to highlight what is known about sex differences in the relationship between stress and drinking. The critical role stress reactivity and negative affect play in initiating and maintaining alcohol use in women is addressed, and the available evidence for sex differences in drinking for negative reinforcement as it relates to brain stress systems is presented. This review discusses the critical structures and neurotransmitters that may underlie sex differences in stress-related alcohol use (e.g., prefrontal cortex, amygdala, norepinephrine, corticotropin releasing factor, and dynorphin), the involvement of sex and stress in alcohol-induced neurodegeneration, and the role of ovarian hormones in stress-related drinking. Finally, the potential avenues for the development of sex-appropriate pharmacological and behavioral treatments for AUD are identified. Overall, women are generally more likely to drink to regulate negative affect and stress reactivity. Sex differences in the onset and maintenance of alcohol use begin to develop during adolescence, coinciding with exposure to early life stress. These factors continue to affect alcohol use into adulthood, when reduced responsivity to stress, increased affect-related psychiatric comorbidities and alcohol-induced neurodegeneration contribute to chronic and problematic alcohol use, particularly for women. However, current research is limited regarding the examination of sex in the initiation and maintenance of alcohol use. Probing brain stress systems and associated brain regions is an important future direction for developing sex-appropriate treatments to address the role of stress in AUD.

Neurobiological Considerations for Tobacco Use Disorder

PURPOSE OF REVIEW

Neurobiological studies of tobacco/nicotine use examining genetic, molecular, functional, and behavioral correlates have improved our understanding of nicotine/tobacco dependence and have informed treatment. Recent work extending previously established findings and reporting novel methodologies and discoveries in preclinical and human studies are reviewed.

RECENT FINDINGS

Recent work in preclinical models has focused on the differential roles of nicotinic receptor subtypes and nicotine's effects on neural systems beyond cortico-striatal dopaminergic pathways, and utilizing advanced methodologies such as pharmacogenetics, optogenetics and rodent fMRI to identify targets for treatment. Likewise, human neuroimaging studies have identified molecular and functional dynamic shifts associated with tobacco/nicotine use that further inform treatment.

SUMMARY

Nicotine/tobacco use is associated with widespread neural adaptations that are persistent and function to maintain addiction. The continued identification of genetic, molecular, neural, and behavioral endophenotypes related to nicotine/tobacco use, dependence, and addiction will facilitate the development and delivery of personalized treatment.

Emotional distress and tobacco demand during the menstrual cycle in female smokers

Fluctuations in ovarian hormones over the menstrual cycle contribute to cigarette reward, however less is known about menstrual cycle influences on emotional distress in female smokers. We examined between-group differences in emotional distress (negative affectivity, emotion dysregulation, distress intolerance) and hypothetical cigarette purchasing (i.e. tobacco demand) among female smokers at three different menstrual stages. Women (n = 32) were non-treatment seeking daily smokers not on hormonal contraceptive, and were currently in their follicular (estradiol-dominant; n = 10), early-mid luteal (progesterone-dominant; n = 15), and late-luteal phase (decreasing progesterone/estradiol; n = 7). Effect sizes are reported given the small sample. Women in the late-luteal phase, relative to the follicular and early-mid luteal phases, reported higher levels of negative affectivity (d = 0.69), emotion dysregulation (d = 1.03), and distress intolerance (d = -0.86). Compared to the early-mid luteal and late-luteal phases, women in the follicular phase reported the highest hypothetical cigarette consumption when cigarettes were free (d = 0.71) and made the largest maximum expenditures on cigarettes (d = 0.74). Findings offer preliminary evidence that the late-luteal phase is characterized by emotional distress, and the follicular phase is associated with elevated tobacco demand, which if replicated could implicate ovarian hormones in emotion-focused smoking.

The influence of smoking and cessation on the human reproductive hormonal balance

Smoking is the most widespread substance dependence in the world. Nicotine and some other components of the cigarette smoke cause various endocrine imbalances, and have negative effects on pituitary, thyroid, adrenal, testicular and ovarian functions. Here, we examined studies that describe the influence of smoking and smoking cessation on the male and female reproductive systems. We also focused on studies providing an account of differences in cessation success rates between men and women. In men, the most common effects associated with smoking are erectile dysfunction and decreasing spermiogram quality. Several groups have studied the effects of cigarette smoking on testosterone levels in men. However, the results have been conflicting. In women, nicotine has an anti-estrogen effect and increases the ratio of androgens to estrogens throughout life. Beside nicotine, other cigarette toxins also cause dysregulation of reproductive and hormonal system, and essentially influence the probability of a successful pregnancy not only in cases of assisted reproduction but also in healthy women. Tobacco addiction is one of the forms of addiction that are generally thought to be different for men and for women. Women are less successful than men in quitting smoking, and nicotine replacement therapy is less effective in female smokers. We also summarize recent studies that have indicated possible reasons.

Postpartum Changes in Mood and Smoking-Related Symptomatology: An Ecological Momentary Assessment Investigation

Introduction

Postpartum smoking relapse is a highly prevalent public health problem. Mood and breast feeding are significantly associated with smoking relapse, although less is known about the temporality of these relationships. Therefore, this study utilized ecological momentary assessments (EMA) to prospectively examine changes in mood and smoking-related symptomatology in relationship to three events-childbirth, termination of breast feeding, and smoking relapse. We expected all three events to significantly alter mood and smoking-related symptomatology.

Methods

We enrolled a sample of pregnant women who had recently quit smoking and intended to remain quit during the postpartum. Participants were randomized to active/placebo progesterone to prevent postpartum relapse. Participants also completed daily EMA to collect data mood and smoking-related symptomatology as well as our three events of interest.

Results

Participants (n = 46) were, on average, 26.5 ± 0.8 years old and, prior to pregnancy, smoked 10.1 ± 0.7 cigarettes/day. We noted a number of significant within- and between-subject relationships. For example, participants reported a 24% decline in negative affect after childbirth (p = .0016). Among those who relapsed to smoking (n = 23), participants randomized to placebo had a significant increase in cigarette craving after relapse (β = 1.06, 95% confidence interval [CI] = 0.62 to 1.49, p value = .0003), whereas participants randomized to active progesterone did not (β = 0.63, 95% CI = -0.35 to 1.62, p value = .1824).

Conclusions

These observations suggest that mood and smoking-related symptomatology are influenced by childbirth, breast feeding, smoking relapse, and use of exogenous progesterone. Future research should explore how these observations may inform novel postpartum smoking relapse-prevention interventions.

Implications

Postpartum smoking relapse has been a persistent public health problem for more than 40 years. Although a number of significant predictors of postpartum smoking relapse have been identified (eg, depression and breast feeding), much of these analyses have relied on cross-sectional and/or self-reported retrospective data. Therefore, for the first time, we utilized ecological momentary assessment to explore the effect of childbirth, termination of breast feeding, and smoking relapse on mood and smoking-related symptomatology (eg, craving). Numerous significant relationships were observed, including a 96% increase in craving after smoking relapse. These novel observations can inform new and effective postpartum smoking relapse-prevention programs.

Role of Exogenous Progesterone in the Treatment of Men and Women with Substance Use Disorders: A Narrative Review

Substance use disorders (SUDs) remain problematic as many individuals are untreated or do not benefit from the currently available interventions. Thus, there is an urgent need to develop novel pharmacological interventions to treat SUDs. Evidence suggests that the female sex hormone, progesterone, attenuates the craving for and the euphoric effects of drugs of abuse. Research to date has demonstrated that progesterone may modulate responses to drugs of abuse and may have utility as a novel treatment for SUDs. A literature search was conducted to identify and examine studies that administered exogenous progesterone. Sixteen publications were identified, exploring the utility of exogenous progesterone or its metabolite, allopregnanolone, among a range of substances, including amphetamines (one study), benzodiazepines (one study), cocaine (nine studies), and tobacco/nicotine (five studies). Results indicated that exogenous progesterone and, its metabolite allopregnanolone, demonstrated preliminary efficacy as a treatment for substance use in both men and women. Notably, progesterone appears to target negative affect and augment cognitive functioning, especially among female substance users. Additional research is needed to explore the potential use of exogenous progesterone and allopregnanolone in the treatment of SUDs, including that associated with alcohol and opioids, but considering the current promising findings, exogenous progesterone and allopregnanolone may have utility as novel pharmacological treatments for SUDs.