Effect of stress on perceived intoxication and the blood alcohol curve in men and women

Alcohol motivations associated with frequency of alcohol use, binge drinking, and alcohol problems among active duty junior enlisted soldiers and non-commissioned officers

Problematic alcohol use is a serious threat to the behavioral health of active-duty Service Members (ADSM), resulting in numerous calls from governmental agencies to better understand mechanistic factors contributing to alcohol misuse within the military. Alcohol use motives are reliable predictors of alcohol-related behaviors and are considered malleable targets for prevention and intervention efforts. However, empirical research indicates that drinking motives vary across contextually distinct populations. Although some research has been conducted among veteran and reservist populations, limited work has been specifically focused on ADSM and no research has evaluated motives and alcohol metrics among ADSM based on military rank. Participants for the current study included 682 ADSM recruited from a large military installation in the U.S. Structural equation modeling evaluated associations between four drinking motives (i.e., enhancement, social, conformity, coping) and three alcohol misuse metrics (i.e., alcohol frequency, binge frequency, alcohol problems). Three models were evaluated: one full (combined) model and two separate models based on military rank - junior enlisted (i.e., E1-E4) and non-commissioned officers (NCOs) (i.e., E5-E9). Results for junior enlisted ADSM indicated that coping and enhancement motives were most strongly associated with all alcohol misuse metrics. However, among NCOs, results indicated that alcohol problems were only associated with coping motives. Notably, results also indicated that alcohol use motives accounted for substantively more variance across all alcohol-related metrics among NCOs. Findings generally support extant military-related literature indicating use of alcohol for coping (e.g., with anxiety) as the motivation most consistently associated with increased alcohol misuse. However, novel findings highlight enhancement motives - using alcohol to attain some positive internal reward - as another, often stronger, motivation impacting alcohol use outcomes. Further, findings highlight notable distinctions between alcohol use motives (i.e., coping vs. enhancement) and the impact of alcohol use motives (i.e., effect size) on alcohol metrics between junior enlisted and NCOs.

Acute stress and alcohol exposure during adolescence result in an anxious phenotype in adulthood: Role of altered glutamate/endocannabinoid transmission mechanisms

BACKGROUND

Stressful episodes and high alcohol consumption during adolescence are considered major risk factors for the development of psychiatric disorders in adulthood. Identification of mechanisms underlying these early events, which enhanced vulnerability to mental illness, is essential for both their prevention and treatment.

METHODS

Male Wistar rats were used to investigate the long-term effects of early restraint stress and intermittent alcohol exposure (intragastric administration of 3 g/kg ethanol; 4 days/week for 4 weeks during adolescence) on anxiety-like behavior and the expression of signaling systems associated with emotional behaviors [e.g., corticosterone, fatty acid-derived molecules and endocannabinoid enzymes, glutamate receptor subunits, corticotropin releasing hormone receptors (CRHR1 and CRHR2) and neuropeptide Y receptors (NPY1R and NPYR2)] in the blood and amygdala.

RESULTS

Overall, both stress and alcohol exposure during adolescence induced anxiogenic-like behaviors, increased plasma levels of corticosterone and increases in the amygdalar expression of the cannabinoid CB₂ receptor and certain subunits of glutamate receptors (i.e., mGluR1, mGluR5 and NMDAR1) in young adult rats. In addition, there were specific main effects of alcohol exposure on the expression of the cannabinoid CB₁ receptor, monoacylglycerol lipase (MAGL) and NPY2R in the amygdala, and significant increases were observed in rats exposed to alcohol. Interestingly, there were significant interaction effects between restraint stress and alcohol exposure on the expression of plasma 2-arachidonoyl glycerol (2-AG), and both CRHR1,2 and NPY1R in the amygdala. Thus, the restraint stress was associated with increased 2-AG levels, which was not observed in rats exposed to alcohol. The alcohol exposure was associated with an increased expression of CRHR1,2 but the restraint stress prevented these increases (stress alcohol rats). In contrast, NPY1R was only increased in rats exposed to stress and alcohol. Finally, we did not observe any potentiation of the behavioral and molecular effects by the combination of stress and alcohol, which is concordant with an overall ceiling effect on some of the variables.

CONCLUSION

Separate and combined early stress and alcohol induced a common anxious phenotype with increased corticosterone in adulthood. However, there were differences in the amygdalar expression of signaling systems involved in maladaptive changes in emotional behavior. Therefore, our results suggest the existence of partially different mechanisms for stress and alcohol exposures.

Effect of trauma-related stress after alcohol consumption on perceived likelihood of negative consequences and willingness to drive

BACKGROUND

Alcohol-related motor vehicle crashes are a major preventable cause of death in the United States. One potential factor that may modulate the influence of alcohol on driving-related cognitions and decision-making is trauma-related stress. Indeed, in addition to compelling research indicating that both acute trauma-related stress and acute alcohol consumption may independently affect driving-related risky decision-making, there is reason to believe that the combination of these antecedents may have an exacerbating effect.

METHODS

The current study evaluated the influence of induction of acute trauma-related stress (via script-driven imagery) after alcohol consumption (0.06% Breath Alcohol Concentration [BrAC]) on driving-related cognitions - perceived likelihood of negative consequences and willingness to drive - among 25 trauma-exposed (currently symptomatic) adult drinkers from the community (M = 24.08; 36.0% female).

RESULTS

Participants who were acutely exposed to trauma-related stress after alcohol consumption evidenced lower perceived likelihood of being pulled over by a police officer (ηp2 = 0.38, large effect size) and lower perceived likelihood of getting in an accident (ηp2 = 0.17, medium-to-large effect size) relative to participants exposed to a neutral cue; conversely, participants exposed to trauma-related stress after alcohol consumption evidenced greater willingness to drive (d = 1.16, large effect size) than participants exposed to a neutral cue.

CONCLUSIONS

Generally, findings suggest that individuals with a trauma history that are acutely exposed to trauma-related stressors (e.g., reminders of their traumatic experience) may be particularly vulnerable to poorer driving-related decision-making after alcohol consumption. Results provide a meaningful target for the development of intoxicated driving prevention and intervention efforts geared specifically for individuals with trauma history.

Speech volume indexes sex differences in the social-emotional effects of alcohol

Men and women differ dramatically in their rates of alcohol use disorder (AUD), and researchers have long been interested in identifying mechanisms underlying male vulnerability to problem drinking. Surveys suggest that social processes underlie sex differences in drinking patterns, with men reporting greater social enhancement from alcohol than women, and all-male social drinking contexts being associated with particularly high rates of hazardous drinking. But experimental evidence for sex differences in social-emotional response to alcohol has heretofore been lacking. Research using larger sample sizes, a social context, and more sensitive measures of alcohol's rewarding effects may be necessary to better understand sex differences in the etiology of AUD. This study explored the acute effects of alcohol during social exchange on speech volume--an objective measure of social-emotional experience that was reliably captured at the group level. Social drinkers (360 male; 360 female) consumed alcohol (.82 g/kg males; .74 g/kg females), placebo, or a no-alcohol control beverage in groups of 3 over 36-min. Within each of the 3 beverage conditions, equal numbers of groups consisted of all males, all females, 2 females and 1 male, and 1 female and 2 males. Speech volume was monitored continuously throughout the drink period, and group volume emerged as a robust correlate of self-report and facial indexes of social reward. Notably, alcohol-related increases in group volume were observed selectively in all-male groups but not in groups containing any females. Results point to social enhancement as a promising direction for research exploring factors underlying sex differences in problem drinking.

Alcohol and Emotional Contagion: An Examination of the Spreading of Smiles in Male and Female Drinking Groups

Researchers have hypothesized that men gain greater reward from alcohol than women. However, alcohol-administration studies testing participants drinking alone have offered weak support for this hypothesis. Research suggests that social processes may be implicated in gender differences in drinking patterns. We examined the impact of gender and alcohol on "emotional contagion"-a social mechanism central to bonding and cohesion. Social drinkers (360 male, 360 female) consumed alcohol, placebo, or control beverages in groups of three. Social interactions were video recorded, and both Duchenne and non-Duchenne smiling were continuously coded using the Facial Action Coding System. Results revealed that Duchenne smiling (but not non-Duchenne smiling) contagion correlated with self-reported reward and typical drinking patterns. Importantly, Duchenne smiles were significantly less "infectious" among sober male versus female groups, and alcohol eliminated these gender differences in smiling contagion. Findings identify new directions for research exploring social-reward processes in the etiology of alcohol problems.

Female rats exposed to stress and alcohol show impaired memory and increased depressive-like behaviors

Exposure to daily life stressors is associated with increases in anxiety, depression, and overall negative affect. Alcohol or other psychoactive drugs are often used to alleviate stress effects. While females are more than twice as likely to develop mood disorders and are more susceptible to dependency than males, they are infrequently examined. In this study, female rats received no stress/no alcohol control (CON), alcohol alone (ALC), stress alone (STR), or stress plus alcohol (STR+ALC). Stress consisted of restraint for 6h/day/7days, and alcohol was administered immediately following restraint via gastric gavage at a dose of 2.0g/kg. Dependent measures included tests utilizing object recognition (OR), Y-maze, elevated plus maze (EPM), forced swim (FST), blood alcohol content, corticosterone levels, and body weights. ALC, STR+ALC, but not stress alone, impaired memory on OR. All treatments impaired spatial memory on the Y-maze. Anxiety was not affected on the EPM, but rats treated with alcohol or in combination with stress showed increased immobility on the FST, suggestive of alcohol-induced depression. Previously, we found alcohol reversed deleterious effects of stress on memory and mood in males, but current results show that females reacted negatively when the two treatments were combined. Thus, responses to alcohol, stress and their combination suggest that sex specific treatments are needed for stress-induced behavioral changes and that self-medicating with alcohol to cope with stress maybe deleterious in females.

Alcohol administration blocks stress-induced impairments in memory and anxiety, and alters hippocampal neurotransmitter receptor expression in male rats

Chronic exposure to stress has many deleterious effects on behavior, which can often lead to self-medication with anxiolytics, antidepressants, or alcohol. We determined the effects of alcohol administration following a stressor on established behavioral, physiological, and neural responses to stress. Male Sprague-Dawley rats received: No alcohol/No stress (CON), Alcohol alone (ALC), Stress alone (STR), or Stress plus Alcohol (STR+ALC). For seven consecutive days, two cohorts received an oral dose of 2.0 g/kg of either 20% ethanol or saline. In Cohort 1, behavioral testing began after the final treatment (day-8). Memory was tested using the object recognition (OR) and Y-maze, anxiety on the plus maze, and depression on the forced swim task. Memory on OR and Y-maze tasks was impaired in the ALC and STR groups. This deficit was reversed in the STR+ALC group, which performed not differently from the CON group. Stress alone was associated with increased anxiety, which was alleviated with alcohol treatment. No treatment effects were found in the forced swim task. In Cohort 2, hippocampal GABAα4 was upregulated in the STR+ALC group and GluN2B was upregulated in the ALC and STR+ALC groups. The STR+ALC group in Cohort 1 showed enhanced corticosterone levels after forced swim. The STR+ALC group in Cohort 2 showed increased corticosterone levels on day-1 of treatment and a habituation by day-7. In conclusion, this study found a reversal of stress-induced deficits in cognition and anxiety when alcohol was given post-stress, and changes in neurotransmitter receptor expression may contribute to these behavioral effects.

The separate and combined effects of alcohol and nicotine on anticipatory anxiety: a multidimensional analysis

Individuals who smoke cigarettes are significantly more likely to smoke more when they drink alcohol. Indeed, smoking and drinking appear strongly linked, at both between- and within-person levels of analyses. Anecdotal evidence further suggests that alcohol consumption in combination with smoking cigarettes reduces anxiety, yet the mechanisms by which this may occur are not well understood. The current study assessed the separate and combined effects of alcohol and nicotine on self-reported and psychophysiological (startle eyeblink magnitude) indices of anxiety. Results indicated that alcohol provided anxiolytic benefits alone and in combination with nicotine, as evidenced by significant reductions in startle eyeblink magnitude. According to self-reported anxiety, alcohol and nicotine exerted a conjoint effect on diminishing increases in anxiety subsequent to a speech stressor. These data highlight the importance of studying both the separate and combined effects of these two widely used substances, as well as the advantages of employing a multimodal assessment of emotional response.

Increases in anxiety-like behavior induced by acute stress are reversed by ethanol in adolescent but not adult rats

Repeated exposure to stressors has been found to increase anxiety-like behavior in laboratory rodents, with the social anxiety induced by repeated restraint being extremely sensitive to anxiolytic effects of ethanol in both adolescent and adult rats. No studies, however, have compared social anxiogenic effects of acute stress or the capacity of ethanol to reverse this anxiety in adolescent and adult animals. Therefore, the present study was designed to investigate whether adolescent [postnatal day (P35)] Sprague-Dawley rats differ from their adult counterparts (P70) in the impact of acute restraint stress on social anxiety and in their sensitivity to the social anxiolytic effects of ethanol. Animals were restrained for 90 min, followed by examination of stress- and ethanol-induced (0, 0.25, 0.5, 0.75, and 1 g/kg) alterations in social behavior using a modified social interaction test in a familiar environment. Acute restraint stress increased anxiety, as indexed by reduced levels of social investigation at both ages, and decreased social preference among adolescents. These increases in anxiety were dramatically reversed among adolescents by acute ethanol. No anxiolytic-like effects of ethanol emerged following restraint stress in adults. The social suppression seen in response to higher doses of ethanol was reversed by restraint stress in animals of both ages. To the extent that these data are applicable to humans, the results of the present study provide some experimental evidence that stressful life events may increase the attractiveness of alcohol as an anxiolytic agent for adolescents.

Does expectancy affect alcohol absorption?

Many factors influence alcohol absorption, yet few studies have addressed the issue of whether or not experimental manipulations themselves may affect alcohol absorption. The current balanced placebo design study comparing the expectancy effects of root beer and non-alcoholic beer vehicles resulted in significantly lower blood alcohol levels in the root beer condition than in the beer condition even though alcohol doses were the same. Two possible explanations are discussed; differences in expectancy may have affected absorption, or fructose in the root beer may have slowed absorption of alcohol relative to the maltose in beer. The literature does not provide strong evidence for either of the hypotheses. The implication of this study's results is that alcohol absorption rate may be an important source of confounding effects in behavioral research in the laboratory, because it may be affected by beverages or other experimental conditions.

The effect of stress on absorption of acetaminophen

RATIONALE

There is a large variability in the response to pharmacological treatment. Some studies have linked this variability to stress levels, i.e., stress may slow and/or reduce absorption of drugs.

OBJECTIVES

The present experiment investigated the hypothesis that stress slows absorption of drugs.

METHODS

Twenty-four volunteers participated in a within-subjects design with three conditions, each lasting 70 min. Subjects watched a movie hypothesized to induce stress, subjects listened to music hypothesized to reduce stress, and in a control condition no stimuli were presented. Each condition was spaced 2 days or more apart. In each condition, subjects received 500 mg oral acetaminophen. Measures of stress and acetaminophen levels were obtained every 10 min.

RESULTS

Indices of subjective stress and arousal and cortisol, were increased during the movie compared to control. Subjective arousal and cortisol were decreased during music compared to control. However, acetaminophen levels were the same across time in all three experimental conditions.

CONCLUSIONS

There was no effect of the experimental manipulations on acetaminophen absorption, indicating that stress was not related to drug absorption. However, stress could play a role in other processes related to drug pharmacokinetics.

Alcohol problems among a community sample: longitudinal influences of stress, coping, and gender

This study examined the relationships among stress, coping methods, and alcohol-use associated problems within a longitudinal, community sample of males and females who were followed from adolescence through young adulthood. While fewer females than males were categorized as "dependent users," these females were more debilitated in terms of the number of alcohol-related problems experienced from age 15 through age 25. Measures of both chronic and proximal levels of personal stress and negative coping styles were most helpful in explaining problems with alcohol use. Distal measures of stress and coping, while perhaps serving as mediators or moderators of other important constructs, did not appear to have a direct effect on the outcome measure.

Gender and alcohol dosing: a procedure for producing comparable breath alcohol curves for men and women

Gender differences in peak breath alcohol concentrations (BrACs) reached in alcohol administration studies can make the interpretation of study findings difficult. This study evaluated the CBAC computer program as a way of minimizing gender differences in the BrAC curve. After consuming a predrink meal that was adjusted by body mass, 31 female and 27 male subjects consumed an alcoholic beverage targeted for either 0.04% or 0.08%. Mean peak BrACs for women and men were not significantly different. Similarly, the four BrAC readings obtained over the first 2 hr postdrink showed no gender differences. A dose x gender interaction was observed on time to peak BrAC, with women reaching peak BrAC faster than men only in the high dose groups. By decreasing gender differences in BrAC curves, this dosing procedure can aid in reducing the potential confound of dose and gender.

Stress, social support and health-related behavior: a study of smoking, alcohol consumption and physical exercise

The effects of academic examination stress on health behavior was assessed in university students. It was hypothesized that the anticipation of examinations would lead to increases in cigarette smoking and alcohol consumption, and to decreases in physical activity, and that effects would be particularly salient in students with low social supports. One hundred eighty students were divided into exam-stress (51 women, 64 men) and control (49 women, 16 men) groups, and were assessed at baseline and then within 2 weeks of exams, or an equivalent point for the control group. Perceived stress, emotional well-being and health behaviors were assessed by questionnaire and interview. The exam-stress group reported significant increases in perceived stress and emotional distress between baseline and exam sessions, but responses were not affected by social support availability. The controls showed no systematic changes in health behaviors. In the exam-stress group, smoking increased by an average of 54.7% between sessions in women with few social supports, but remained stable in men. There was a decrease in alcohol consumption of 17.5% in students with high social support between sessions, while those with low social supports showed an average increase of 18.5%. Physical activity decreased between baseline and exam sessions in the exam-stress group, but was not affected by social support. The results are discussed in relation to the effects of naturally occurring episodic stress on health behaviors, and the role of social support in moderating responses.

Variability of ethanol absorption and breath concentrations during a large-scale alcohol administration study

Ethanol disposition was evaluated in 77 female and 97 male college seniors during an alcohol challenge study. All were regular drinkers who exceeded legal intoxication levels at least twice a month by history. A standard ethanol dose (females, 0.43 g/kg; males, 0.51 g/kg) was administered over 10 min, after a 4-hr fast, and breath alcohol concentrations (BrACs) were measured for 2 hr. Intersubject variability in BrACs was greatest early in the study, during ethanol absorption; the coefficient of variation decreased from 39% at 14 min to 14% at 125 min after the start of drinking. The time to peak BrAC varied from 10 to 91 min after the start of drinking (mean 39.6 min). Mean BrACs were significantly lower in females than males; mean peak BrACs were 0.054 g/210 liters in females and 0.058 g/210 liters in males (p = 0.031). The beta- and r-values for both genders were higher than those typically used in ethanol dose calculation formulas. Data are discussed to direct future research. The constants used in Widmark's formula need to be revised differentially for males and females in this population to reach specific target BrACs. Furthermore, substantial variability in absorption rates must be accounted for when assessing rising versus falling limb BrAC phenomena.

The effects of stress and coping on daily alcohol use in women

To evaluate the notion that perceived stress and drinking covary over time, daily logs were periodically collected over a 6-month period from 32 middle-aged women. Results indicated that significantly less alcohol was consumed on high-stress weeks than low-stress weeks. Problem-focused (P-F) coping preference moderated this relationship, with low P-F copers consuming more alcohol per occasion than did high P-F copers but only during low-stress weeks. These findings support a model of stress and alcohol use that includes coping preference as an important moderator of women's drinking. In addition, our data are consistent with the notion that stress can influence alcohol consumption but that low P-F women regulate their use, preferring to delay their drinking until after the termination of the stressor.