Smoking as a complex but critical covariate in neurobiological studies of posttraumatic stress disorders: a review

Decreased anxiety-like behavior in a selectively bred high nicotine-preferring rat line

Genetic vulnerability contributes significantly to the individual variability observed in nicotine dependence. Selective breeding for sensitivity to a particular effect of abused drugs has produced rodent lines useful for studying genetic vulnerability to drug addiction. Previous research showed that anxiety-related personality traits are associated with nicotine dependence. Therefore, we examined the differences in anxiety-like behavior between a high nicotine-preferring rat line and their controls. At the beginning of the study, all rats, naïve to any drug, were exposed sequentially to open field arena, marble-burying and elevated plus-maze paradigms. In the second step, all rats received nicotine in drinking water for 7 weeks. Behavioral tests were rerun on the final 2 weeks of chronic nicotine treatment. Elevated plus-maze testings under basal condition and during chronic nicotine treatment showed that the time spent on the open arms, preference for being in the open arms, and the latency to enter the closed arms were higher, whereas open arm avoidance index was lower in nicotine-preferring rats compared to the controls. In the open field test, nicotine-preferring rats spent longer time in the central zone and excreted less fecal pellets; they buried less marbles in the marble-burying test. These findings indicate a lower level of anxiety-like behavior in nicotine-preferring rat line under basal conditions and during chronic nicotine treatment. We conclude that lower anxiety level in nicotine-preferring rat line is consistent with novelty-seeking personality type and may increase vulnerability to nicotine dependence in this rat line.

Effectiveness of drugs acting on adrenergic receptors in the treatment for tobacco or alcohol use disorders: systematic review and meta-analysis

AIM

To assess the efficacy of drugs directly acting on alpha- and beta-adrenergic receptors in the treatment of patients suffering from tobacco or alcohol use disorder.

METHODS

Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, studies were identified through PUBMED, EMBASE, the Cochrane Central Register of Controlled Trials and clinicaltrial.gov. We selected only randomized controlled trials with adult patients with tobacco or alcohol use disorders according to DSM-5 criteria. Interventions included any molecule having a direct pharmacological action on alpha- or beta-adrenergic receptors (agonist or antagonist). Comparators were placebo or other validated pharmacotherapies. The duration of the intervention was a minimum of 1 month, with 3 months of follow-up. Measurements included smoking cessation for tobacco; for alcohol, we selected abstinence, alcohol consumption (drinks per day or week) and heavy drinking days (HDD). Ten studies with tobacco and six with alcohol use disorder were included in the qualitative synthesis and fifteen studies in the quantitative analysis.

RESULTS

We found that clonidine, an alpha-2 agonist, significantly increased smoking abstinence [relative risk = 1.39 with a 95% confidence interval (CI) = 1.04, 1.84]. Beta-blockers had no significant effect on smoking abstinence. The alpha-1 antagonists prazosin and doxazosin decreased alcohol consumption [SMD = -0.32 (-0.56, -0.07)] but had no effect on abstinence or HDD.

CONCLUSIONS

The noradrenaline system may represent a promising mechanism to target in tobacco and alcohol use disorders.

Moderated mediation for exercise maintenance in pain and posttraumatic stress disorder: A randomized trial

This study utilizes the Science of Behavior Change (SOBC) experimental medicine approach to evaluate the effects of a 3-month, individually prescribed progressive exercise training program on neurobiological, cognitive and motivational mechanisms by which our exercise-training paradigm may foster exercise maintenance. We will investigate hypothesized relationships between exercise-training associated augmentation of neuropeptide Y (NPY) system function and improvements in self-regulation and reward sensitivity-cognitive control and motivational processes posited to promote self-efficacy and intrinsic motivation, which have been shown to predict exercise maintenance. This study will recruit Veterans with chronic low back pain and posttraumatic stress disorder (PTSD). Procedures include a baseline, acute cardiopulmonary exercise challenge assessment that will inform the exercise prescription for a 12-week progressive exercise training program comprised of three 45-minute aerobic exercise sessions per week-all of which will be supervised by an exercise physiologist. Additionally, a week-7 and week-14 exercise challenge assessment will track changes in NPY system function and the variables of interest. We hypothesize that increases in the capacity to release NPY in response to acute exercise testing will be associated with improvements in self-regulation and reward sensitivity, which will in turn be associated with self-efficacy and intrinsic motivation to maintain regular exercise. Ninety participants will be randomized either to the "active exercise training condition" or to the "wait list symptom monitoring condition". The study aims to demonstrate the feasibility of procedures and elucidate mechanisms relevant to developing individually prescribed, motivationally based exercise regimens to reduce negative consequences of PTSD and low back pain over the long-term. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Tobacco dependence is associated with increased risk for multi-morbid clustering of posttraumatic stress disorder, depressive disorder, and pain among post-9/11 deployed veterans

RATIONALE

Tobacco use is highly prevalent among individuals with posttraumatic stress disorder (PTSD), depressive disorders, and pain. Research has revealed pairwise relationships among these conditions but has not examined more complex relationships that may influence symptom severity, chronicity, and treatment outcome.

OBJECTIVE

To examine the clustering of current PTSD, depressive disorders, and clinically significant pain according to current tobacco use and dependence among post-9/11 deployed veterans.

METHODS

Logistic regression was used to examine the clustering of these conditions in relationship to current tobacco use/dependence, while adjusting for age and total combat exposure, in 343 post-9/11 deployed veterans enrolled in the Translational Research Center for TBI and Stress Disorders (TRACTS) cohort (Mage = 32.1 + 8.3 years; 38% current tobacco use; 25% low and 12% moderate/high tobacco dependence).

RESULTS

A three-way clustering of PTSD, depressive disorder, and pain was more likely than any single or pairwise combination of these conditions in moderate/high tobacco-dependent veterans compared to tobacco non-users (adjusted ORs = 3.50 to 4.18). This multi-morbidity cluster also was associated with increased PTSD severity.

CONCLUSIONS

Moderate to high dependence on tobacco is associated with substantially increased clustering of PTSD, depression, and clinically significant pain in veterans. Research examining synergistic interactions among these conditions, biological vulnerabilities shared among them, and the direct impact of tobacco use on the pathophysiology of PTSD, depression, and pain is needed. The results of such work may spur development of more effective integrated treatments to reduce the negative impact of these multi-morbid conditions on veterans' wellbeing and long-term health.

Relationships between cerebrospinal fluid GABAergic neurosteroid levels and symptom severity in men with PTSD

Allopregnanolone and pregnanolone (together termed allo + pregnan) are neurosteroid metabolites of progesterone that equipotently facilitate the action of gamma-amino-butyric acid (GABA) at GABA_A receptors. The adrenal steroid dehydroepiandrosterone (DHEA) allosterically antagonizes GABA_A receptors and facilitates N-methyl-D-aspartate (NMDA) receptor function. In prior research, premenopausal women with posttraumatic stress disorder (PTSD) displayed low cerebrospinal fluid (CSF) levels of allo + pregnan [undifferentiated by the gas chromatography-mass spectrometry (GC-MS) method used] that correlated strongly and negatively with PTSD reexperiencing and negative mood symptoms. A PTSD-related decrease in the ratio of allo + pregnan to 5α-dihydroprogesterone (5α-DHP: immediate precursor for allopregnanolone) suggested a block in synthesis of these neurosteroids at 3α-hydroxysteroid dehydrogenase (3α-HSD). In the current study, CSF was collected from unmedicated, tobacco-free men with PTSD (n = 13) and trauma-exposed healthy controls (n = 17) after an overnight fast. Individual CSF steroids were quantified separately by GC-MS. In the men with PTSD, allo + pregnan correlated negatively with Clinician-Administered PTSD Scale (CAPS-IV) total (ρ=-0.74, p = 0.006) and CAPS-IV derived Simms dysphoria cluster (ρ=-0.71, p = 0.01) scores. The allo+pregnan to DHEA ratio also was negatively correlated with total CAPS (ρ=-0.74, p = 0.006) and dysphoria cluster (ρ=-0.79, p = 0.002) scores. A PTSD-related decrease in the 5α-DHP to progesterone ratio indicated a block in allopregnanolone synthesis at 5α-reductase. This study suggests that CSF allo + pregnan levels correlate negatively with PTSD and negative mood symptoms in both men and women, but that the enzyme blocks in synthesis of these neurosteroids may be sex-specific. Consideration of sex, PTSD severity, and function of 5α-reductase and 3α-HSD thus may enable better targeting of neurosteroid-based PTSD treatments.

Nicotinic Cholinergic System in the Hypothalamus Modulates the Activity of the Hypothalamic Neuropeptides During the Stress Response

BACKGROUND

The hypothalamus harbors high levels of cholinergic neurons and axon terminals. Nicotinic acetylcholine receptors, which play an important role in cholinergic neurotransmission, are expressed abundantly in the hypothalamus. Accumulating evidence reveals a regulatory role for nicotine in the regulation of the stress responses. The present review will discuss the hypothalamic neuropeptides and their interaction with the nicotinic cholinergic system. The anatomical distribution of the cholinergic neurons, axon terminals and nicotinic receptors in discrete hypothalamic nuclei will be described. The effect of nicotinic cholinergic neurotransmission and nicotine exposure on hypothalamic-pituitaryadrenal (HPA) axis regulation at the hypothalamic level will be analyzed in view of the different neuropeptides involved.

METHODS

Published research related to nicotinic cholinergic regulation of the HPA axis activity at the hypothalamic level is reviewed.

RESULTS

The nicotinic cholinergic system is one of the major modulators of the HPA axis activity. There is substantial evidence supporting the regulation of hypothalamic neuropeptides by nicotinic acetylcholine receptors. However, most of the studies showing the nicotinic regulation of hypothalamic neuropeptides have employed systemic administration of nicotine. Additionally, we know little about the nicotinic receptor distribution on neuropeptide-synthesizing neurons in the hypothalamus and the physiological responses they trigger in these neurons.

CONCLUSION

Disturbed functioning of the HPA axis and hypothalamic neuropeptides results in pathologies such as depression, anxiety disorders and obesity, which are common and significant health problems. A better understanding of the nicotinic regulation of hypothalamic neuropeptides will aid in drug development and provide means to cope with these diseases. Considering that nicotine is also an abused substance, a better understanding of the role of the nicotinic cholinergic system on the HPA axis will aid in developing improved therapeutic strategies for smoking cessation.

Neurotransmitter, Peptide, and Steroid Hormone Abnormalities in PTSD: Biological Endophenotypes Relevant to Treatment

PURPOSE OF REVIEW

This review summarizes neurotransmitter, peptide, and other neurohormone abnormalities associated with posttraumatic stress disorder (PTSD) and relevant to development of precision medicine therapeutics for PTSD.

RECENT FINDINGS

As the number of molecular abnormalities associated with PTSD across a variety of subpopulations continues to grow, it becomes clear that no single abnormality characterizes all individuals with PTSD. Instead, individually variable points of molecular dysfunction occur within several different stress-responsive systems that interact to produce the clinical PTSD phenotype. Future work should focus on critical interactions among the systems that influence PTSD risk, severity, chronicity, comorbidity, and response to treatment. Effort also should be directed toward development of clinical procedures by which points of molecular dysfunction within these systems can be identified in individual patients. Some molecular abnormalities are more common than others and may serve as subpopulation biological endophenotypes for targeting of currently available and novel treatments.

Posttraumatic Stress Disorder and Gastrointestinal Disorders in the Danish Population

BACKGROUND

Evidence for the association between posttraumatic stress disorder (PTSD) and gastrointestinal (GI) disorders is mixed, owing in part to methodologic differences across studies. Furthermore, studies which have combined GI disorders or symptoms for examination as one overall category may potentially obscure associations between PTSD and individual GI diagnoses.

METHODS

This nationwide cohort study examined the incidence of all major nonmalignant GI disorders in patients with a prior PTSD diagnosis (n = 4,076), compared with the general population incidence from 1995 to 2013, using Danish medical registry data. We examined differences by sex, age, marital status, psychiatric and somatic comorbidity, and follow-up time. Risks, standardized incidence rates (SIRs), and confidence intervals (95% CIs) were calculated.

RESULTS

Risk of any GI disorder among PTSD patients was 25% (95% CI: 21%, 29%); the SIR for any GI disorder was 1.8 (95% CI: 1.7, 2.0). Risk and SIRs varied by disorder (e.g., no association with diverticula of the intestines [SIR: 1.1, 95% CI: 0.83, 1.5]; stronger association with peptic ulcer, site unspecified [SIR: 3.3, 95% CI: 1.8, 5.5]). Stratified analyses revealed that some associations were stronger for persons ages 16-39 or unmarried at PTSD diagnosis, persons with comorbid psychiatric diagnoses, and in the year following PTSD diagnosis.

CONCLUSIONS

This study documents associations between clinician-diagnosed PTSD and all major nonmalignant GI disorders in an unselected nationwide cohort with long follow-up. Differences in associations across GI disorders and important modifiers may account for previous conflicting research findings.

Chronic Smoking, Trait Anxiety, and the Physiological Response to Stress

BACKGROUND AND OBJECTIVES

Both chronic smoking and trait anxiety have been associated with dysregulations in psychobiological stress response systems. However, these factors have not been studied in conjunction. We expected trait anxiety and smoking status to attenuate stress reactivity. Furthermore, we expected an allostatic load effect resulting in particularly attenuated stress reactivity in high-anxious smokers. In addition, high-anxious smokers were expected to exhibit increased urges to smoke in response to stress.

METHODS

115 smokers and 37 nonsmokers, aged 18-64 years, completed a laboratory session including mental stressors such as evaluated public speaking and mental arithmetic. Trait anxiety was assessed using Spielberger's State-Trait Anxiety Inventory. Cardiovascular autonomic indices, salivary cortisol, and the desire to smoke were measured at baseline, during stressors, and at recovery.

RESULTS

Regression analyses showed that smokers exhibited attenuated cardiovascular stress responses in comparison to nonsmokers. Higher trait anxiety predicted attenuated systolic blood pressure responses to stress. No interaction effect of smoking status and trait anxiety was found in stress response measures. Higher trait anxiety predicted an increased desire to smoke in response to stress among smokers.

CONCLUSION

Results indicate that both smoking status and trait anxiety are associated with blunted sympatho-adrenal cardiovascular stress reactivity. Elevated urges to smoke in response to stress found among smokers with high trait anxiety suggest an important role of anxiety in smoking propensity and relapse.

Supplemental nicotine preloading for smoking cessation in posttraumatic stress disorder: Results from a randomized controlled trial

BACKGROUND

Individuals with posttraumatic stress disorder (PTSD) are more likely to smoke and more likely to relapse following a quit attempt than individuals without PTSD. Thus, there is a significant need to study promising interventions that might improve quit rates for smokers with PTSD. One such intervention, supplemental nicotine patch-preloading, entails the use of nicotine replacement therapy prior to quitting. Objective The objective of this study was to conduct a randomized controlled trial of the efficacy of supplemental nicotine patch-preloading among smokers with PTSD. We hypothesized that, relative to participants in the placebo condition, participants in the nicotine patch-preloading condition would: (1) smoke less and experience reduced craving for cigarettes during the nicotine patch-preloading phase; (2) experience less smoking-associated relief from PTSD symptoms and negative affect during the preloading phase; and (3) exhibit greater latency to lapse, and higher short- and long-term abstinence rates.

METHODS

Sixty-three smokers with PTSD were randomized to either nicotine or placebo patch for three weeks prior to their quit date. Ecological momentary assessment was used to assess craving, smoking, PTSD symptoms, and negative affect during the preloading period.

RESULTS

Nicotine patch-preloading failed to reduce smoking or craving during the preloading phase, nor was it associated with less smoking-associated relief from PTSD symptoms and negative affect. Moreover, no differences were observed between the treatment conditions for time to lapse, 6-week abstinence, or 6-month abstinence.

CONCLUSIONS

The findings from the present research suggest that supplemental nicotine patch-preloading is unlikely to substantially enhance quit rates among smokers with PTSD.

Cholinergic Signaling Controls Conditioned Fear Behaviors and Enhances Plasticity of Cortical-Amygdala Circuits

We examined the contribution of endogenous cholinergic signaling to the acquisition and extinction of fear- related memory by optogenetic regulation of cholinergic input to the basal lateral amygdala (BLA). Stimulation of cholinergic terminal fields within the BLA in awake-behaving mice during training in a cued fear-conditioning paradigm slowed the extinction of learned fear as assayed by multi-day retention of extinction learning. Inhibition of cholinergic activity during training reduced the acquisition of learned fear behaviors. Circuit mechanisms underlying the behavioral effects of cholinergic signaling in the BLA were assessed by in vivo and ex vivo electrophysiological recording. Photostimulation of endogenous cholinergic input (1) enhances firing of putative BLA principal neurons through activation of acetylcholine receptors (AChRs), (2) enhances glutamatergic synaptic transmission in the BLA, and (3) induces LTP of cortical-amygdala circuits. These studies support an essential role of cholinergic modulation of BLA circuits in the inscription and retention of fear memories.

Pilot Cases of Combined Cognitive Processing Therapy and Smoking Cessation for Smokers With Posttraumatic Stress Disorder

Posttraumatic stress disorder (PTSD) and smoking are often comorbid, and both problems are in need of improved access to evidence-based treatment. The combined approach could address two high-priority problems and increase patient access to both treatments, but research is needed to determine whether this is feasible and has promise for addressing both PTSD and smoking. We collected data from 15 test cases that received a treatment combining two evidence-based treatments: cognitive processing therapy-cognitive version (CPT-C) for PTSD and integrated care for smoking cessation (ICSC). We explored two combined treatment protocols including a brief (six-session) CPT-C with five follow-up in-person sessions focused on smoking cessation (n=9) and a full 12-session CPT-C protocol with ICSC (n=6). The combined interventions were feasible and acceptable to patients with PTSD making a quit attempt. Initial positive benefits of the combined treatments were observed. The six-session dose of CPT-C and smoking cessation resulted in 6-month bioverified smoking abstinence in two of nine participants, with clinically meaningful PTSD symptom reduction in three of nine participants. In the second cohort (full CPT-C and smoking treatment), both smoking and PTSD symptoms were improved, with three of six participants abstinent from smoking and four of six participants reporting clinically meaningful reduction in PTSD symptoms. Results suggested that individuals with PTSD who smoke are willing to engage in concurrent treatment of these problems and that combined treatment is feasible.

Resilient but addicted: The impact of resilience on the relationship between smoking withdrawal and PTSD

Nicotine use is common among people with posttraumatic stress disorder (PTSD). Resilience, which is reflected in one's ability to cope with stress, has been shown to be associated with lower cigarette smoking and posttraumatic stress symptoms, but relationships among these three variables have not been examined. This study investigates the relationships of resilience and nicotine withdrawal with each other and in relation to PTSD symptoms. Participants were 118 cigarette smokers with PTSD seeking treatment for PTSD and nicotine use. Data were randomly cross-sectionally sampled from three time points: week 0, week 12, and week 27 of the study. Hierarchical multiple regression analyses revealed main effects of both resilience and nicotine withdrawal symptoms on PTSD severity, controlling for the sampled time point, negative affect, and expired carbon monoxide concentration. Consistent with prior research, PTSD severity was higher among individuals who were less resilient and for those who had greater nicotine withdrawal. There was an interaction between resilience and nicotine withdrawal on self-reported PTSD severity, such that greater resilience was associated with lower PTSD severity only among participants with low nicotine withdrawal symptoms. Among individuals with high nicotine withdrawal, PTSD severity was high, regardless of resilience level. These results suggest that resilience is a protective factor for PTSD severity for those with low levels of nicotine withdrawal, but at high levels of nicotine withdrawal, the protective function of resilience is mitigated.

The Association of Panic Disorder, Posttraumatic Stress Disorder, and Major Depression With Smoking in American Indians

INTRODUCTION

Rates of cigarette smoking are disproportionately high among American Indian populations, although regional differences exist in smoking prevalence. Previous research has noted that anxiety and depression are associated with higher rates of cigarette use. We asked whether lifetime panic disorder, posttraumatic stress disorder, and major depression were related to lifetime cigarette smoking in two geographically distinct American Indian tribes.

METHODS

Data were collected in 1997-1999 from 1506 Northern Plains and 1268 Southwest tribal members; data were analyzed in 2009. Regression analyses examined the association between lifetime anxiety and depressive disorders and odds of lifetime smoking status after controlling for sociodemographic variables and alcohol use disorders. Institutional and tribal approvals were obtained for all study procedures, and all participants provided informed consent.

RESULTS

Odds of smoking were two times higher in Southwest participants with panic disorder and major depression, and 1.7 times higher in those with posttraumatic stress disorder, after controlling for sociodemographic variables. After accounting for alcohol use disorders, only major depression remained significantly associated with smoking. In the Northern Plains, psychiatric disorders were not associated with smoking. Increasing psychiatric comorbidity was significantly linked to increased smoking odds in both tribes, especially in the Southwest.

CONCLUSIONS

This study is the first to examine the association between psychiatric conditions and lifetime smoking in two large, geographically diverse community samples of American Indians. While the direction of the relationship between nicotine use and psychiatric disorders cannot be determined, understanding unique social, environmental, and cultural differences that contribute to the tobacco-psychiatric disorder relationship may help guide tribe-specific commercial tobacco control strategies.

Posttraumatic stress symptoms and tobacco abstinence effects in a non-clinical sample: evaluating the mediating role of negative affect reduction smoking expectancies

The relation between posttraumatic stress symptoms and smoking is well documented but poorly understood. The present investigation sought to evaluate the impact of posttraumatic stress symptoms on subjective and behavioral tobacco abstinence effects both directly and indirectly through negative affect reduction smoking outcome expectancies. Participants included 275 (68.7% male; Mage =43.9, 10+ cig/day) adult non-treatment seeking smokers, who attended two counterbalanced laboratory sessions (16 h of smoking deprivation vs ad libitum smoking), during which they completed self-report measures of withdrawal symptoms and mood followed by a smoking lapse task in which they could earn money for delaying smoking and purchase cigarettes to smoke. Results supported a mediational pathway whereby higher baseline symptoms of posttraumatic stress predicted greater endorsement of expectancies that smoking will effectively reduce negative affect, which in turn predicted greater abstinence-provoked exacerbations in nicotine withdrawal symptoms and negative affect. Posttraumatic stress symptoms also predicted number of cigarettes purchased independent of negative affect reduction expectancies, but did not predict delaying smoking for money. Findings highlight tobacco abstinence effects as a putative mechanism underlying posttraumatic stress disorder (PTSD)-smoking comorbidity, indicate an important mediating role of beliefs for smoking-induced negative affect reduction, and shed light on integrated treatment approaches for these two conditions.

New Insights into the Mechanisms of Action of Cotinine and its Distinctive Effects from Nicotine

Tobacco consumption is far higher among a number of psychiatric and neurological diseases, supporting the notion that some component(s) of tobacco may underlie the oft-reported reduction in associated symptoms during tobacco use. Popular dogma holds that this component is nicotine. However, increasing evidence support theories that cotinine, the main metabolite of nicotine, may underlie at least some of nicotine's actions in the nervous system, apart from its adverse cardiovascular and habit forming effects. Though similarities exist, disparate and even antagonizing actions between cotinine and nicotine have been described both in terms of behavior and physiology, underscoring the need to further characterize this potentially therapeutic compound. Cotinine has been shown to be psychoactive in humans and animals, facilitating memory, cognition, executive function, and emotional responding. Furthermore, recent research shows that cotinine acts as an antidepressant and reduces cognitive-impairment associated with disease and stress-induced dysfunction. Despite these promising findings, continued focus on this potentially safe alternative to tobacco and nicotine use is lacking. Here, we review the effects of cotinine, including comparisons with nicotine, and discuss potential mechanisms of cotinine-specific actions in the central nervous system which are, to date, still being elucidated.

Tobacco smoking and mental illness: important considerations

Tobacco smoking is a contributory factor in the death of 50% of individuals who are regular or heavy smokers (The Office of Tobacco Control Ireland defines a regular smoker as someone who smokes 11-20 per day and a heavy smoker as someone who smokes 21 or more cigarettes per day). The World Health Organisation (WHO) regards tobacco smoking as the leading preventable cause of death worldwide. In Ireland, approximately 750,000 people smoke tobacco regularly (23.5% of the population) with 7,000 Irish people dying annually from smoking-related causes. Although there are no exact figures for prevalence rates of smoking in individuals with mental illness in Ireland, international studies unequivocally state that the prevalence of smoking is significantly higher in those with mental illness, with greater nicotine intake and increased prevalence of nicotine dependence also reported. Furthermore people with mental illness experience greater withdrawal symptoms and have lower cessation rates when attempting to stop smoking compared to the general population.

Association of DHEA, DHEAS, and cortisol with childhood trauma exposure and post-traumatic stress disorder

There has been a great deal of interest in the role of the neuroendocrine hormones of the hypothalamic-pituitary-adrenal (HPA) axis in the expression of stress-related psychopathology such as post-traumatic stress disorder (PTSD). This investigation examined the association of PTSD and childhood maltreatment with three key HPA axis hormones: cortisol, dehydroepiandrosterone (DHEA), and dehydroepiandrosterone sulfate (DHEAS). Regression analyses were undertaken on a sample of 43 participants with and 57 participants without PTSD. Results demonstrated that after controlling for age, sex, and PTSD status, exposure to childhood maltreatment was significantly associated with cortisol secretion [F(4,95)=11.68, ΔR(2)=0.11, P=0.0009] and cortisol/DHEA ratio [F(4,95)=6.20, ΔR(2)=0.05, P=0.01]. PTSD status was not associated with any of these neuroendocrine variables. Findings are discussed in the context of the complexity of the relationship of these neuroendocrine variables with trauma exposure and trauma-related psychopathology. It is suggested that DHEA(S) or cortisol/DHEA(S) ratios may not be biomarkers of specific forms of psychopathology per se, but that, instead, the severity and developmental timing of trauma may set the HPA axis in ways that are reflected in interactions among these neuroendocrine hormones. In adulthood, these HPA axis hormones may continue to be dynamically affected by personal and environmental resources.

The association of dehydroepiandrosterone and dehydroepiandrosterone sulfate with anxiety sensitivity and electronic diary negative affect among smokers with and without posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is associated with increased smoking initiation, maintenance, and relapse. Dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEAS) are neurosteroids that have been associated with mood measures as well as smoking status, and nicotine is associated with increased DHEA and DHEAS levels. Given the difficulties with mood experienced by smokers with PTSD, the purpose of the current study was to evaluate the association between negative affect and anxiety sensitivity with DHEA and DHEAS levels. Ninety-six smokers with and without PTSD provided blood samples for neurosteroid analyses and completed self-report measures of anxiety sensitivity and electronic diary ratings of negative affect. As expected, PTSD smokers reported higher levels of anxiety sensitivity (F(1,94) = 20.67, partial η2 = 0.18, P < 0.0001) and negative affect (F(1,91) = 7.98, partial η2 = 0.08, P = 0.006). After accounting for age and sex, DHEAS was significantly inversely associated with both anxiety sensitivity (F(3,92) = 6.97, partial η2 = 0.07, P = 0.01) and negative affect (F(3,87) = 10.52, partial η2 = 0.11, P = 0.002) across groups. Effect sizes indicated that these effects are moderate to high. No significant interactions of diagnosis and DHEA(S) levels with mood measures were detected. Given that nicotine is known to elevate DHEA(S) levels, these results suggest that DHEAS may serve as a biomarker of the association between mood and nicotine among smokers. Implications for the results include (1) the use of DHEAS measurement across time and across quit attempts and (2) the potential for careful use of DHEA supplementation to facilitate abstinence during smoking cessation.

Nicotinic α7 receptors enhance NMDA cognitive circuits in dorsolateral prefrontal cortex

The cognitive function of the highly evolved dorsolateral prefrontal cortex (dlPFC) is greatly influenced by arousal state, and is gravely afflicted in disorders such as schizophrenia, where there are genetic insults in α7 nicotinic acetylcholine receptors (α7-nAChRs). A recent behavioral study indicates that ACh depletion from dlPFC markedly impairs working memory [Croxson PL, Kyriazis DA, Baxter MG (2011) Nat Neurosci 14(12):1510-1512]; however, little is known about how α7-nAChRs influence dlPFC cognitive circuits. Goldman-Rakic [Goldman-Rakic (1995) Neuron 14(3):477-485] discovered the circuit basis for working memory, whereby dlPFC pyramidal cells excite each other through glutamatergic NMDA receptor synapses to generate persistent network firing in the absence of sensory stimulation. Here we explore α7-nAChR localization and actions in primate dlPFC and find that they are enriched in glutamate network synapses, where they are essential for dlPFC persistent firing, with permissive effects on NMDA receptor actions. Blockade of α7-nAChRs markedly reduced, whereas low-dose stimulation selectively enhanced, neuronal representations of visual space. These findings in dlPFC contrast with the primary visual cortex, where nAChR blockade had no effect on neuronal firing [Herrero JL, et al. (2008) Nature 454(7208):1110-1114]. We additionally show that α7-nAChR stimulation is needed for NMDA actions, suggesting that it is key for the engagement of dlPFC circuits. As ACh is released in cortex during waking but not during deep sleep, these findings may explain how ACh shapes differing mental states during wakefulness vs. sleep. The results also explain why genetic insults to α7-nAChR would profoundly disrupt cognitive experience in patients with schizophrenia.

Predictors of lapse in first week of smoking abstinence in PTSD and non-PTSD smokers

INTRODUCTION

Retrospective research suggests smokers with posttraumatic stress disorder (PTSD) lapse more quickly after their quit date. Ecological momentary assessment (EMA) research is needed to confirm the presence of early smoking lapse in PTSD and form conceptualizations that inform intervention.

METHODS

Smokers with (n = 55) and without (n = 52) PTSD completed alarm-prompted EMA of situational and psychiatric variables the week before and after a quit date, and self-initiated EMA following smoking lapses. Blood samples at baseline and on the quit date allowed assessment of dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEA(S)).

RESULTS

PTSD was related to shorter time to lapse (hazard ratio [HR] = 1.677, 95% CI: 1.106-2.544). Increased smoking abstinence self-efficacy was related to longer time to lapse (HR = 0.608, 95% CI: 0.430-0.860). Analyses of participants' real-time reports revealed that smokers with PTSD were more likely to attribute first-time lapses to negative affect ( = 5.412, p = .020), and trauma reminders (Fisher's exact p = .003**). Finally, the quit date decrease in DHEA(S) was related to shorter time to lapse (HR = 1.009, 95% CI: 1.000-1.018, p < .05).

CONCLUSIONS

Results provide evidence of shorter time to first smoking lapse in PTSD, and add to evidence that early lapse occasions are more strongly related to trauma reminders, negative affect, and cravings in smokers with PTSD.

Biological studies of post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is the only major mental disorder for which a cause is considered to be known: that is, an event that involves threat to the physical integrity of oneself or others and induces a response of intense fear, helplessness or horror. Although PTSD is still largely regarded as a psychological phenomenon, over the past three decades the growth of the biological PTSD literature has been explosive, and thousands of references now exist. Ultimately, the impact of an environmental event, such as a psychological trauma, must be understood at organic, cellular and molecular levels. This Review attempts to present the current state of this understanding on the basis of psychophysiological, structural and functional neuroimaging, and endocrinological, genetic and molecular biological studies in humans and in animal models.

Smoking intensity and severity of specific symptom clusters in posttraumatic stress disorder

Smoking prevalence among patients with posttraumatic stress disorder (PTSD) is over 40%. Baseline data from the VA Cooperative Studies Program trial of integrated versus usual care for smoking cessation in veterans with PTSD (N = 863) were used in multivariate analyses of PTSD and depression severity, and 4 measures of smoking intensity: cigarettes per day (CPD), Fagerström Test for Nicotine Dependence (FTND), time to first cigarette, and expired carbon monoxide. Multivariate regression analysis showed the following significant associations: CPD with race (B = -7.16), age (B = 0.11), and emotional numbing (B =0 .16); FTND with race (B = -0.94), education (B = -0.34), emotional numbing (B = 0.04), significant distress (B = -0.12), and PHQ-9 (B = 0.04); time to first cigarette with education (B = 0.41), emotional numbing (B = -0.03), significant distress (B = 0.09), and PHQ-9 (B = -0.03); and expired carbon monoxide with race (B = -9.40). Findings suggest that among veterans with PTSD, White race and emotional numbing were most consistently related to increased smoking intensity and had more explanatory power than total PTSD symptom score. Results suggest specific PTSD symptom clusters are important to understanding smoking behavior in patients with PTSD.

Cotinine enhances the extinction of contextual fear memory and reduces anxiety after fear conditioning

Posttraumatic stress disorder (PTSD) is an anxiety disorder triggered by traumatic events. Symptoms include anxiety, depression and deficits in fear memory extinction (FE). PTSD patients show a higher prevalence of cigarette smoking than the general population. The present study investigated the effects of cotinine, a tobacco-derived compound, over anxiety and contextual fear memory after fear conditioning (FC) in mice, a model for inducing PTSD-like symptoms. Two-month-old C57BL/6J mice were separated into three experimental groups. These groups were used to investigate the effect of pretreatment with cotinine on contextual fear memory and posttreatment on extinction and stability or retrievability of the fear memory. Also, changes induced by cotinine on the expression of extracellular signal-regulated kinase (ERK)1/2 were assessed after extinction in the hippocampus. An increase in anxiety and corticosterone levels were found after fear conditioning. Cotinine did not affect corticosterone levels but enhanced the extinction of contextual fear, decreased anxiety and the stability and/or retrievability of contextual fear memory. Cotinine-treated mice showed higher levels of the active forms of ERK1/2 than vehicle-treated mice after FC. This evidence suggests that cotinine is a potential new pharmacological treatment to reduce symptoms in individuals with PTSD.

How traumatic is breast cancer? Post-traumatic stress symptoms (PTSS) and risk factors for severe PTSS at 3 and 15 months after surgery in a nationwide cohort of Danish women treated for primary breast cancer

BACKGROUND

The literature shows considerable between-study variation in the prevalence of post-traumatic stress symptoms (PTSS) among women with breast cancer. Our aim was, therefore, to explore the prevalence of and risk factors for cancer-related PTSS in a nationwide inception cohort of women treated for primary breast cancer.

METHODS

In all, 68% of all Danish women receiving surgery for primary breast cancer between October 2001 and March 2004 completed a questionnaire at 3 months post surgery (n=3343), which included the impact of event scale (IES). In all, 94% of the disease-free women also completed a follow-up questionnaire at 15 months post surgery. Data on pre-cancer demographic, socioeconomic, and psychiatric status were obtained from national registries. The Danish Breast Cancer Cooperative Group and surgical departments provided information on disease variables, treatment, and comorbidity.

RESULTS

At 3 months post surgery, 20.1% had IES total scores suggesting severe PTSS (35), compared with 14.3% at 15 months. In all, 48% with severe PTSS at 3 months also had scores above the cutoff at 15 months. Main predictors of severe PTSS at 15 months were low social status, previous physical and mental illness, axillary lymph node involvement (>3), and reduced physical functioning (PF) at 3 months.

CONCLUSION

The results confirm that receiving a breast cancer diagnosis can be a significant traumatic experience, and that many women experience persistent cancer-related PTSS. Low social status, poor health status, low levels of PF, and disease severity were found to be risk factors for severe PTSS.

Temporal relations between sleep problems and both traumatic event exposure and PTSD: a critical review of the empirical literature

There has been growing interest in the interrelations among traumatic event exposure, posttraumatic stress disorder (PTSD), and sleep problems. A wealth of research has examined the associations among these factors and there is an emerging literature focused on how sleep problems relate to both traumatic event exposure and PTSD across time. The current review provides a detailed analysis of studies pertaining to the temporal patterning of sleep problems and traumatic event-related factors (e.g., traumatic event exposure, PTSD) and draws conclusions regarding the current state of this literature. Research coalesces to suggest (1) exposure to a traumatic event can interfere with sleep, (2) PTSD is related to the development of self-reported sleep problems, but evidence is less clear regarding objective indices of sleep, and (3) limited evidence suggests sleep problems may interfere with recovery from elevated posttraumatic stress levels. Future research now needs to focus on understanding mechanisms involved in these patterns to inform the prevention and treatment of comorbid sleep problems and PTSD.

Biomarker characteristics of alcohol use in the U.S. Army

The objective of this study was to collect data providing information about the biomarker characteristics of alcohol use among a sample of military personnel in the U.S. Army. Military personnel enrolled in the Army Substance Abuse Program at the Walter Reed Army Medical Center in Washington, DC, received a comprehensive assessment that included a panel of direct and indirect biomarkers. A total of 80 records were reviewed to assess biomarker results. Higher Alcohol Use Disorders Identification Test scores correlated with higher gamma glutamyltransferase levels. All subjects tested negative on the initial breathalyzer. All subjects completed an initial ethyl glucuronide and approximately one-third received a positive report. A second positive ethyl glucuronide did correlate with a positive third and fourth result. Military personnel deployed to an area of combat operations reported tobacco use more frequently than military personnel not assigned to an area of combat operations. A broad range of assessment tools, including traditional interviews, standardized questionnaires, indirect, and direct biomarkers, provide clinicians the techniques to screen alcohol use disorders. Direct biomarkers are a valuable assessment tool but must be integrated with the other components of the diagnostic evaluation.

Test of the role of nicotine dependence in the relation between posttraumatic stress disorder and panic spectrum problems

Posttraumatic stress disorder (PTSD) frequently co-occurs with panic spectrum problems. Relatively little empirical work has tested possible mechanisms accounting for this association. Nicotine dependence often ensues subsequent to PTSD onset and research suggests smoking high numbers of cigarettes daily may lead to panic problems. The current study tested the hypotheses that nicotine dependence partially mediates the relations between PTSD and both panic attacks and panic disorder within a nationally representative sample of 5,692 (3,020 women; M(Age) = 45, SD = 18) adults from the National Comorbidity Survey-Replication. Results were consistent with hypotheses. These findings support the theory suggesting smoking among people with PTSD may be involved in the development of panic problems.

A critical review of the empirical literature on the relation between anxiety and puberty

The current paper critically reviews the empirical literature focused on the association between puberty and anxiety. A detailed review of more than 45 empirical articles is provided. There is some evidence that among girls, but not boys, a more advanced pubertal status (controlling for age) is associated with higher reported anxiety symptoms. Also among girls, earlier pubertal timing is linked to higher anxiety scores. It is unclear whether early puberty may lead to increased anxiety or if high anxiety influences pubertal timing. With respect to hormones, there were relatively few significant associations for girls, although this literature is very small. Among boys, several studies reported positive associations between both gonadal and adrenal hormones and anxiety. The direction of effect for these finding is also unstudied. The primary limitation of the hormone-anxiety literature pertains to the absence of pubertal measures in samples of youth in which hormones are measured. The paper concludes with a comprehensive examination of the methodological strengths and weaknesses of the literature and recommendations for future work.

Nicotine dependence and psychiatric and substance use comorbidities in a sample of American Indian male veterans

BACKGROUND

American Indians and Alaska Natives have the highest rates of nicotine dependence in the U.S. However, studies analyzing associations between nicotine dependence and psychiatric and substance use disorders in these groups have been limited.

METHODS

This study analyzes the co-occurrence of current and lifetime DSM-III-R nicotine dependence with psychiatric and substance use disorders in a community sample of 480 American Indian male veterans.

RESULTS

Lifetime nicotine dependence (23.3%) was associated with all lifetime disorders studied, including alcohol use and drug use disorders, affective and anxiety disorders, PTSD, pathological gambling and antisocial personality disorder. Current nicotine dependence was present in 19% of the sample and significantly associated with current affective and gambling disorder.

CONCLUSIONS

Substantial co-morbidity exists between nicotine dependence and other substance abuse and psychiatric disorders among this sample of American Indian male veterans, particularly for lifetime diagnoses. Screening for all psychiatric disorders among American Indian/Alaska Native smokers may be warranted. Although these results are similar to those observed among the general U.S. population, unique risk factors exist among American Indians/Alaska Natives which may require further attention. Specific public health and clinical interventions to reduce the rate of nicotine dependence among American Indians/Alaska Natives are recommended.

Smoking and posttraumatic stress symptoms among adolescents: does anxiety sensitivity matter?

The present study examined the hypothesized moderating role of anxiety sensitivity (AS) in the relationship between lifetime smoking history and posttraumatic stress symptoms among 64 traumatic event-exposed adolescents. As predicted, the relationship between smoking status and posttraumatic stress symptom levels was moderated by AS. Specific facets of AS also were examined. Disease concerns, but not unsteady, mental illness, or social concerns, moderated the association between smoking and symptom level. These findings are generally consistent with findings from adult samples, but importantly extend this area of research to another phase of the lifespan.

Relationship between PTSD symptomatology and nicotine dependence severity in crime victims

Smoking rates are higher and cessation rates are lower among individuals with posttraumatic stress disorder (PTSD) compared to the general population, thus understanding the relationship between PTSD and nicotine dependence is important. In a sample of 213 participants with a crime-related trauma (109 with PTSD), the relationship between PTSD status, smoking status (smoker vs. non-smoker), substance abuse diagnosis (SUD), PTSD symptoms, and sex was assessed. SUD diagnosis was significantly related to smoking status, but PTSD symptomatology and sex were not. Among smokers (n=117), increased nicotine dependence severity was associated with being male and with increased level of PTSD avoidance symptoms. Correlations indicated that PTSD avoidance and hyperarousal symptom clusters and total PTSD symptom scores were significantly related to nicotine dependence severity in males, while PTSD symptomatology in general did not correlate with dependence severity for females. The results suggest that level of PTSD symptomatology, particularly avoidance symptoms, may be important targets for smoking cessation treatment among male smokers who have experienced a traumatic event.

beta2 Nicotinic acetylcholine receptor availability in post-traumatic stress disorder

Availability of nicotinic acetylcholine receptors containing beta2 subunits (beta2-nAChRs) was studied in unmedicated, symptomatic patients with post-traumatic stress disorder (PTSD) and healthy control subjects, all current non-smokers. A subgroup of participants had a history of smoking. Availability of beta2-nAChRs in the mesiotemporal cortex, prefrontal cortex, thalamus and striatum was determined using the radiotracer [123I]5-IA-85380 ([123I]5-IA) and single-photon emission computed tomography (SPECT). PTSD symptoms were assessed using the Clinician-Administered PTSD Scale (CAPS). Never-smoking PTSD patients compared to never-smoking healthy controls showed significantly higher [123I]5-IA binding in the mesiotemporal cortex (ANOVA: F=6.21, d.f.=1, 11, p=0.030). Among all PTSD patients, there was a significant correlation between the re-experiencing symptom cluster and thalamic [123I]5-IA binding (R2=0.66, p=0.019, Bonferroni corrected). These findings not only suggest an involvement of beta2-nAChRs in the pathophysiology of PTSD but also raise the possibility that this receptor may be a novel molecular target for drug development.

The role of the hippocampus in mediating emotional responses to nicotine and cannabinoids: a possible neural substrate for functional interactions

The endocannabinoid system is involved in the regulation of behavioural and physiological stress-related responses. Nicotine exerts complex effects on emotional behaviour, and its withdrawal may result in depressive and anxiogenic-like symptoms. Cannabinoid receptor agonists and nicotine induce biphasic effects in diverse tests of unconditioned anxiety, alter adrenocortical activity and affect hippocampus-dependent contextual fear conditioning. Upon exposure to stressful stimuli, central endocannabinoid and cholinergic systems appear to be activated in key limbic areas such as hippocampus and amygdala, which might contribute to adaptive cognitive and emotional strategies to cope with aversive situations. Numerous studies indicate the existence of functional interactions between nicotine and cannabinoids, particularly in relation to anxiety-related processes. An overlapping distribution of CB1 and nicotinic acetylcholine receptors in the hippocampus is observed and the endocannabinoid system exerts a modulatory role over the hippocampal cholinergic system. In this review, we point to the hippocampus as a relevant neural substrate for cannabinoid-nicotine interactions, notably as regards emotional responses. After a general description of the cannabinoid and nicotinic systems, we review their implications in unconditioned anxiety, depressive-like behaviour and fear conditioning. Then we discuss the role of both systems in modulating stress-induced changes at cellular, endocrine and behavioural levels and their possible involvement in hippocampal neurogenesis. Although we mainly focus on animal data, some relevant human studies are also discussed.

A decrease in the plasma DHEA to cortisol ratio during smoking abstinence may predict relapse: a preliminary study

RATIONALE

Increases in depressive symptoms during smoking cessation have been associated with risk for relapse. Several studies have linked plasma levels of cortisol and dehydroepiandrosterone (DHEA) or DHEA-sulfate (DHEAS) to depressive symptoms.

OBJECTIVES

To determine whether changes in plasma cortisol, DHEA, or DHEAS levels and emergence of depressive symptoms during smoking cessation are associated with smoking relapse.

MATERIALS AND METHODS

Subjects were healthy non-medicated men and women, aged 39+/-12 years, who smoked, on average, 22 cigarettes per day. Depressive symptoms, smoking withdrawal symptoms, and plasma steroid levels were measured before and after 8 days of verified smoking abstinence. Relapse status at day 15 was then determined.

RESULTS

In the full sample (n=63), there was a trend for changes in depressive symptoms to be associated with relapse. In the subset of 25 subjects with plasma neuroactive steroid data, there was a significant interaction between the change in the plasma DHEA/cortisol ratio from day 0 to day 8 and relapse status at day 15. This ratio was similar before abstinence, but lower at day 8 in relapsed, compared to abstinent, subjects. Changes in the DHEA/cortisol ratio tended to predict changes in depressive symptoms in the women only.

CONCLUSION

A decrease in the plasma DHEA/cortisol ratio during 8 days of smoking abstinence was associated with relapse over the following week. Further research is needed to fully characterize sex-specific relationships between abstinence-induced changes in neuroactive steroid levels, depressive or withdrawal symptoms, and relapse. Such research may lead to new interventions for refractory smoking dependence.