Effects of Assessment Frequency on Subjective Intoxication Ratings After Alcohol Consumption

BACKGROUND: It is common for subjective intoxication measures to be administered frequently throughout an experimental session. It is unclear, however, whether repeated assessments affect the experience of intoxication. This study examined the effect of assessing subjective intoxication levels during alcohol consumption on subsequent perceptions of intoxication after drinking. METHODS: Forty-two participants consumed a moderate dose of alcohol (men, 82 g/kg; women, 0.74 g/kg) during a 30-min period. Participants either reported or did not report subjective intoxication levels at 10-min intervals during the drinking period. After the drink, all participants rated their level of subjective intoxication on several occasions. RESULTS: Individuals who reported their intoxication during the drinking period reported higher levels after consumption than did those who did not rate their intoxication during drinking. CONCLUSIONS: These data suggest the potential for reactivity effects when conducting repeated assessments of perceived subjective intoxication.     

Catching the Alcohol Buzz: An Examination of the Latent Factor Structure of Subjective Intoxication

Background:  The goal of this study was to examine the latent structure among measures of alcohol-induced subjective feelings of intoxication from a behavioral pharmacology perspective.
Methods:  Data on subjective intoxication, measured concomitantly by the Subjective High Assessment Scale, Biphasic Alcohol Effect Scale, and the Short Version of the Profile of Mood States, were collected at 3 levels of breath alcohol concentration during an alcohol administration study in a sample of heavy drinkers ( n  = 135).
Results:  Results of exploratory factor analyses supported a 3-factor model which captured the following dimensions of subjective intoxication: (1) stimulation and other pleasant effects, (2) sedative and unpleasant effects, and (3) alleviation of tension and negative mood. The tension-reduction factor was most consistently associated with more frequent drinking and alcohol problems in this sample.
Conclusions:  These findings support the notion that the neuropharmacological and behavioral effects of alcohol are multifaceted and cannot be simply defined as either positive or negative. Rather, moderate levels of intoxication appear to have concomitant dimensions of positive reinforcement, negative reinforcement, and punishment. This study also suggests that factor scores may be useful in future alcohol administration studies to reduce the number of comparisons and perhaps increase statistical power to detect meaningful effects.     

Smoking and Intoxication after Alcohol Challenge in Women and Men: Genetic Influences

In an earlier analysis, men and women who were current or former smokers were found to report feeling less intoxicated on average than nonsmokers after ingestion of a challenge dose of alcohol. Here, we examine whether differences in subjective response to alcohol and a tendency to smoke cigarettes are transmitted together in families; and, if so, whether this association might be entirely explained by the same heritable factors that influence alcohol intake (as we might expect if both smoking and subjective intoxication are influenced by some general susceptibility for substance use). Alcohol challenge data on 388 Australian male and female twins (194 complete pairs) were reanalyzed using multivariate genetic analysis to evaluate the association between cigarette smoking and self-report intoxication after a standard dose of alcohol. In women, we could not reject the hypothesis of complete genetic overlap between effects on intoxication rating and history of smoking, and a significant residual genetic correlation between smoking and postalcohol intoxication persisted even when genetic influences on alcohol consumption were controlled for. In men, the familial association seemed to be largely environmentally mediated and associated with differences in drinking history. These findings prompt the question of whether, in some individuals, cigarette smoking may contribute to the development of tolerance to the effects of alcohol.     

The Identification of Alcohol Intoxication by Police

BACKGROUND: The identification of alcohol intoxication by police, bartenders, social hosts, and potential passengers is an important issue in the prevention of alcohol-related driving accidents. This study examines the ability of police officers to correctly identify and make ratings of the sobriety of target drinkers presented on video. METHODS: Raters were asked to determine (1) whether the target drinker had been drinking alcohol, (2) whether it was "okay" to serve the target another drink, and (3) whether the target drinker was "okay" to drive. A rater confidence score for each target evaluated, as well as demographic characteristics about the raters, was obtained. RESULTS: Drinkers were accurately targeted to low (0.08-0.09%), medium (0.11-0.13%), and high (0.15-0.16%) blood alcohol concentrations (BACs) by using a method previously described. At lower BACs, most police officers were unable to identify whether or not targets had been drinking. Raters were "pretty sure" that targets in the 0.15-0.16% range had been drinking and "not sure" whether or not they should be served another drink or drive a car. CONCLUSIONS: The ability of raters to reliably identify target drinkers who were too intoxicated to drive safely was not obtained until the BACs were relatively high. These results suggest that prevention measures must focus on improving behavioral observations made of potential drunk drivers. Implications for bartenders and social hosts are discussed.     

Alcohol Price and Intoxication in College Bars

Background:  Many population studies find that alcohol prices are inversely related to alcohol consumption and alcohol-related problems, including among college students and young adults. Yet, little is known about the "micro-level" effects of alcohol price on the behavior of individual consumers in natural drinking settings such as college bars. Therefore, we assessed patron's cost per gram of ethanol consumed at on-premise drinking establishments and its association with intoxication upon leaving an establishment.
Methods:  On 4 consecutive nights during April 2008, data were collected from 804 patrons exiting 7 on-premise establishments in a bar district located adjacent to a large university campus in the southeastern United States. Anonymous interview and survey data were collected as well as breath alcohol concentration (BrAC) readings. We calculated each patron's expenditures per unit of ethanol consumed based on self-reported information regarding the type, size, number, and cost of consumed drinks.
Results:  A multivariable model revealed that a 10-cent increase in cost per gram of ethanol at on-premise establishments was associated with a 30% reduction in the risk of exiting an establishment intoxicated (i.e., BrAC ≥ 0.08 g/210 l).
Conclusions:  The results are consistent with economic theory and population-level research regarding the price elasticity of alcoholic beverages, which show that increases in alcohol prices are accompanied by less alcohol consumption. These findings suggest that stricter regulation of the drink discounting practices of on-premise drinking establishments would be an effective strategy for reducing the intoxication levels of exiting patrons.     

Hormonal Derangements in Patients with Severe Alcohol Intoxication

Controversial results of fluid and electrolyte derangements in patients with moderate alcohol intoxication have been described. However, no information is available about severe alcohol intoxication. We investigated differences of hormonal disorders between alcohol-habituated and alcohol-naive subjects with severe ethanol intoxication. The hormonal derangements and recommendations on therapy of these patients are discussed. Thirty-three patients [10 alcohol-naive (group A) and 23 alcohol-habituated (group 8) subjects] with severe alcohol intoxication (blood ethanol > 200 mg/dl) were selected for the study. Electrolytes and osmolarity of serum and urine, blood ethanol, vasopressin, renin, and aldosterone were determined on admission 2, 4, and 6 hr later. Fluid balance was calculated for each hour. All patients received isotonic saline solution according to urine production. Group A: On admission, serum osmolarity was increased (308 mOsmol/kg). Concomitantly, vasopressin level was elevated on admission (9.12 pglml). Increased serum osmolarity was correlated with elevated vasopressin levels (r= 0.8211; p < 0.005). Serum electrolytes, renin, and aldosterone values were within normal ranges. Group B: On admission, vasopressin level was significantly decreased (0.9 pg/ml), despite an elevated serum osmolarity (309 mOsmol/kg). Serum osmolarity remained high despite a sufficient fluid substitution. In addition, vasopressin level remained suppressed over the observation period. Aldosterone level was significantly increased on admission (319 ng/ml). Accordingly, serum sodium was increased from 142 to 148 mM/liter, and serum potassium was decreased from 3.9 to 3.4 mM/liter. Response to hyperosmolality due to severe alcohol intoxication is different in alcohol-naive and alcohol-habituated subjects. In contrast to alcohol-naive subjects, vasopressin secretion of alcohol-habituated subjects was suppressed rather than elevated despite hyperosmolality. Additionally, in these patients, hyperaldosteronism was observed leading to hypernatremia and hypokalemia. Therefore, infusions containing sodium should be avoided in alcohol-habituated patients.     

Mecamylamine attenuates the subjective stimulant-like effects of alcohol in social drinkers

BACKGROUND: Recent studies have implicated central nicotinic cholinergic receptor systems in the reinforcing properties of alcohol. In laboratory animals, mecamylamine, a central nicotinic receptor antagonist, reduces the consumption of and preference for alcohol. This study investigated the effect of mecamylamine on the subjective responses to alcohol in humans. It was hypothesized that mecamylamine (7.5 and 15 mg) would attenuate the stimulant-like subjective effects of alcohol (0.8 g/kg) and decrease the self-reported desire to consume additional alcohol beverages. METHODS: Fourteen male and 13 female nonsmokers participated in 6 laboratory sessions. During each session, subjects received, in randomized order under double-blinded conditions, a capsule containing mecamylamine (7.5 or 15 mg) or placebo followed by a beverage containing alcohol (0.8 g/kg) or placebo. Physiologic and subjective-effect measures were taken at 30-min intervals for 2 hr after beverage consumption. RESULTS: Mecamylamine attenuated the stimulant and euphoric effects of alcohol and reduced the self-reported desire to consume additional alcohol beverages. This effect was most pronounced in men, even though women exhibited greater physiologic reactions to mecamylamine. CONCLUSIONS: These findings suggest that nicotinic cholinergic receptors are involved in mediating some of the stimulant-like effects of alcohol.     

Alcohol and Secobarbital Effects as a Function of Familial Alcoholism: Extended Intoxication and Increased Withdrawal Effects

Response differences following administration of alcohol between adult males with a positive (FHP) versus negative (FHN) family history of alcoholism have been demonstrated in previous research and are thought to be related to risk for developing alcoholism. If this is so, the pharmacological breadth of addiction risk conferred by a positive family alcoholism history might be studied by determining whether FHP subjects show different responses than FHN to drug classes other than alcohol. We have previously reported on the acute effects of ethanol as compared with secobarbital in FHP and FHN subjects and found that FHP subjects showed greater sensitivity across a variety of subjective measures than FHN subjects for both drug classes. The data reported here are based on an extended data collection period of 3 to 18 hr postingestion, following completion of the acute laboratory portion of the study. Specifically, in the present study, dose-effect timecourse functions for a variety of physiological (heart rate, blood pressure, and breath alcohol level), subjective (analog mood, drug effect, and withdrawal, Subjective High Assessment Scale (SHAS], and psychomotor measures (Digit Symbol Substitution Test and numeric recall) were examined in FHP and FHN college-aged males for secobarbital (0, 100, 200 mg daily) and ethanol (1 g/kg daily). FHP and FHN subjects were matched on light-to-moderate drinking patterns, anthropometric dimensions, age, years of schooling, and drug use. FHP subjects reported more extended intoxication and greater withdrawal effects following both ethanol and the high dose of secobarbital than did FHN subjects.(ABSTRACT TRUNCATED AT 250 WORDS)     

Subjective intoxication in response to alcohol challenge: heritability and covariation with personality,breath alcohol level,and drinking history

BACKGROUND: Numerous studies have identified differences in subjective response to alcohol in subjects differentiated by family history of alcoholism. Results suggest that genetic influences on individual variation in subjective response to alcohol may be a mechanism for genetic effects on alcohol problems. However, direct evidence for genetic effects on subjective response to alcohol is very limited. METHODS: In a sample of 99 adult twin pairs, we studied genetic influences on subjective intoxication after alcohol challenge. The twins ingested a standard dose of ethanol (0.70 g/kg for men/0.65 g/kg for women), and two measures of subjective response to alcohol were assessed. RESULTS: Genetic effects on variation in subjective intoxication reported 1 hr after drinking were significant and substantial: heritability was 0.60 for a 22-item scale and 0.48 for a brief 2-item measure. Self-report measures of neuroticism, psychasthenia, hostility, and family problems shared significant genetic covariation with subjective intoxication. Achieved breath alcohol level, rate of change in breath alcohol on the descending limb, and individual drinking history all shared familial variation with subjective intoxication. No significant genetic effects for subjective intoxication were found 2 hr after drinking, but familial influences remained present, and many of the same personality, drinking history, and breath alcohol variables were predictive of intoxication. CONCLUSIONS: Subjective response to alcohol is heritable, and genetic effects on subjective intoxication are partly shared with genetic effects on personality.     

Subjective Response to Alcohol: A Critical Review of the Literature

Background: Subjective response to alcohol (SR), which reflects individual differences in sensitivity to the pharmacological effects of alcohol, may be an important endophenotype in understanding genetic influences on drinking behavior and alcohol use disorders (AUDs). SR predicts alcohol use and problems and has been found to differ by a range of established risk factors for the development of AUDs (e.g., family history of alcoholism). The exact pattern of SR associated with increased risk for alcohol problems, however, remains unclear. The Low Level of Response Model (LLR) suggests that high‐risk individuals experience decreased sensitivity to the full range of alcohol effects, while the Differentiator Model (DM) asserts that high risks status is associated with increased sensitivity to alcohol's positive effects but decreased sensitivity to negative effects. Aims: The current paper (1) reviews two prominent models of subjective response, (2) reviews extant laboratory‐based research on subjective response, (3) highlights remaining gaps in our understanding and assessment of subjective response, and (4) encourages collaborative efforts to address these methodological and conceptual concerns. Methods: This paper reviews studies which employed placebo‐controlled and non‐placebo‐controlled alcohol challenge paradigms to assess a range of alcohol effects including impairment, stimulation, and sedation. Results: The research literature provides at least partial support for both the LLR and DM models. High‐risk individuals have been shown to have a reduced response to alcohol with respect to sedative or impairing effects, particularly on the descending limb of the blood alcohol curve (BAC). There is also evidence that ascending limb stimulant effects are more pronounced or operate differently for high‐risk individuals. Discussion: Despite commendable advances in SR research, important questions remain unanswered. Inconsistent results across studies may be attributable to a combination of an inadequate understanding of the underlying construct and methodological differences across studies (e.g., number and timing of assessments across the BAC, inclusion of a placebo condition). With respect to the underlying construct, existing measures fail to adequately distinguish between cognitive/behavioral impairment and sedation, aspects of which may be perceived positively (e.g., anxiolysis) due to their ability to act as negative reinforcers. Conclusions: Addressing the concerns raised by the current review will be integral to making meaningful scientific progress in the field of subjective response.     

The Adrenocortical Response to Brain Injury: Correlation with the Severity of Neurologic Dysfunction, Effects of Intoxication, and Patient Outcome

To test the hypothesis that cortisol levels reflect the extent of neurologic dysfunction and predict patient outcome, neurologic function and cortisol levels were determined in 120 traumatically brain injured patients who never received glucocorticoid treatment. Their mean age was 29 years and 78% were men. The impact of intoxication was examined in 59 patients who had ethanol levels measured. Ethanol was detectable in 40 patients and greater than or equal to 100 mg/dl in 31. There were significant correlations between the extent of neurologic dysfunction, determined by the Glasgow Coma Score and plasma cortisol concentrations 1 and 4 days postaccident. Cortisol levels were universally elevated on admission and approached normal 7 days later. Multiple linear regression analysis revealed significant effects of circulating ethanol levels on the association between cortisol concentrations and progressively worsening neurologic function, i.e., ethanol reduced the magnitude of the cortisol elevations in a dose dependent manner, abolishing this relationship at levels above 100 mg/dl. Analysis of the relationships between circulating cortisol levels and patient outcome provided a second method for ascertaining the association between injury severity and the magnitude of adrenocortical activation. Admission and day 1 cortisol concentrations were 25 to 40% lower in patients having good recoveries or moderate disabilities than those who remained severely disabled, persistently vegetative or died; serum cortisol values of less than 20 micrograms/dl one day after the accident were more likely to be associated with a good outcome than a poor one (55 vs. 25%, p less than 0.001). The worsening prognosis of patients having higher cortisol values is further reflected in the duration of acute hospitalization of these individuals.(ABSTRACT TRUNCATED AT 250 WORDS)     

Subjective responses to alcohol: a paradigm shift may be brewing

Background: The meta‐analysis by Quinn and Fromme (2011 ) is reviewed and integrated into the larger field. Guidelines for future research are presented. Results: With results of the meta‐analysis along with those of a recent comprehensive prospective study by our group ( King et al., 2011 ), there is a call to the field to specify terms and integrate theoretical frameworks to advance our knowledge and improve comparisons across trials. Conclusions: The meta‐analysis is both timely and thorough and will provide clinical researchers with important information to move the field forward.