Meghan E. Morean

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 alcohols 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.

E-cigarette Use Among High School and Middle School Adolescents in Connecticut

INTRODUCTION There is limited evidence on electronic cigarette (e-cigarette) use among U.S. adolescents. METHODS Cross-sectional, anonymous surveys conducted in 4 high schools (HS; n = 3,614) and 2 middle schools (MS; n = 1,166) in Connecticut in November 2013 examined e-cigarette awareness, use patterns, susceptibility to future use, preferences, product components used (battery type, nicotine content, flavors), and sources of marketing and access. RESULTS High rates of awareness (MS: 84.3%; HS: 92.0%) and of lifetime (3.5% MS, 25.2 % HS) and current (1.5% MS, 12% HS) use of e-cigarettes was observed. Among those who had not tried e-cigarettes, 26.4% of MS and 31.7% of HS students reported being susceptible to future use. Males (OR = 1.70, p < .01), older students (OR = 1.39, p < .05), Caucasians (OR = 2.01, p < .001), ever cigarette smokers (OR = 13.04, p < .001), and current cigarette smokers (OR = 65.11, p < .001) were more likely to be lifetime e-cigarette users and to report greater future susceptibility (males: OR = 1.30; Caucasians: OR = 1.14; ever cigarette smokers; OR = 3.85; current cigarette smokers; OR = 9.81; ps < .01-.001). Among MS students who were lifetime e-cigarette users, 51.2% reported that e-cigarette was the first tobacco product they had tried. E-cigarettes that were rechargeable and had sweet flavors were most popular. Smokers preferred e-cigarettes to cigarettes. Current cigarette smokers were more likely to initiate with nicotine-containing e-cigarettes, and ever and never cigarette smokers to initiate with e-cigarettes without nicotine. Primary sources for e-cigarette advertisements were televisions and gas stations and, for acquiring e-cigarettes, were peers. CONCLUSIONS Longitudinal monitoring of e-cigarette use among adolescents and establishment of policies to limit access are imperatively needed.

High School Students’ Use of Electronic Cigarettes to Vaporize Cannabis

BACKGROUND AND OBJECTIVES: Electronic cigarette (e-cigarette) use is increasing rapidly among high school (HS) students. Of concern, e-cigarettes can be used to vaporize cannabis, although use rates among adolescents are unknown. We evaluated lifetime rates of using e-cigarettes to vaporize cannabis among all lifetime e-cigarette users (27.9%), all lifetime cannabis users (29.2%), and lifetime users of both e-cigarettes and cannabis (18.8%); common means of vaporizing cannabis including hash oil, wax infused with Δ-9-tetrahydrocannabinol (THC), and dried cannabis; and demographic predictors of using e-cigarettes to vaporize cannabis. METHODS: In the spring of 2014, 3847 Connecticut HS students completed an anonymous survey assessing e-cigarette and cannabis use. RESULTS: Vaporizing cannabis using e-cigarettes was common among lifetime e-cigarette users, lifetime cannabis users, and lifetime dual users (e-cigarette 18.0%, cannabis 18.4%, dual users 26.5%). Students reported using e-cigarettes to vaporize hash oil (e-cigarette 15.4%, cannabis 15.5%, dual users 22.9%) and wax infused with THC (e-cigarette 10.0%, cannabis 10.2%, dual users 14.8%) and using portable electronic vaporizers to vaporize dried cannabis leaves (e-cigarette 19.6%, lifetime cannabis 23.1%, lifetime dual users 29.1%). Binary logistic regression indicated that male students (odds ratio [OR] = 2.05), younger students (OR = 0.64), lifetime e-cigarette users (OR = 5.27), and lifetime cannabis users (OR = 40.89) were most likely to vaporize cannabis using e-cigarettes. Rates also differed by HS attended. CONCLUSIONS: Rates of vaporizing cannabis using e-cigarettes were high. These findings raise concerns about the lack of e-cigarette regulations and the potential use of e-cigarettes for purposes other than vaping nicotine.

The drug effects questionnaire: psychometric support across three drug types.

RationaleThe Drug Effects Questionnaire (DEQ) is widely used in studies of acute subjective response (SR) to a variety of substances, but the format of the DEQ varies widely across studies, and details of its psychometric properties are lacking. Thus, the field would benefit from demonstrating the reliability and validity of the DEQ for use across multiple substances.ObjectiveThe current study evaluated the psychometric properties of several variations of DEQ items, which assessed the extent to which participants (1) feel any substance effect(s), (2) feel high, (3) like the effects, (4) dislike the effects, and (5) want more of the substance using 100-mm visual analog scales.MethodsDEQ data from three placebo-controlled studies were analyzed to examine SR to amphetamine, nicotine, and alcohol. We evaluated the internal structure of the DEQ for use with each substance as well as relationships between scale items, measures of similar constructs, and substance-related behaviors.ResultsResults provided preliminary psychometric support for items assessing each DEQ construct (feel, high, dislike, like, and more).ConclusionsBased on the study results, we identify several common limitations of extant variants of the DEQ and recommend an improved version of the measure. The simplicity and brevity of the DEQ combined with its promising psychometric properties support its use in future SR research across a variety of substances.

Human Laboratory Paradigms in Alcohol Research

BACKGROUND Human laboratory studies have a long and rich history in the field of alcoholism. Human laboratory studies have allowed for advances in alcohol research in a variety of ways, including elucidating neurobehavioral mechanisms of risk, identifying phenotypically distinct subtypes of alcohol users, investigating the candidate genes underlying experimental phenotypes for alcoholism, and testing mechanisms of action of alcoholism pharmacotherapies on clinically relevant translational phenotypes, such as persons exhibiting positive-like alcohol effects or alcohol craving. Importantly, the field of human laboratory studies in addiction has progressed rapidly over the past decade and has built upon earlier findings of alcohols neuropharmacological effects to advancing translational research on alcoholism etiology and treatment. METHODS AND RESULTS To that end, the new generation of human laboratory studies has focused on applying new methodologies, further refining alcoholism phenotypes, and translating these findings to studies of alcoholism genetics, medication development, and pharmacogenetics. The combination of experimental laboratory approaches with the recent developments in neuroscience and pharmacology has been particularly fruitful in furthering our understanding of the impact of individual differences in alcoholism risk and in treatment response. CONCLUSIONS This review of the literature focuses on human laboratory studies of subjective intoxication, alcohol craving, anxiety, and behavioral economics. Each section discusses opportunities for phenotype refinement under laboratory conditions, as well as its application to translational science of alcoholism. A summary and recommendations for future research are also provided.

Subjective alcohol effects and drinking behavior : The relative influence of early response and acquired tolerance

OBJECTIVES (1) To establish the reliability and validity of a modified version of the Self-Rating of Alcohol (SRE) form. (2) To differentiate early subjective alcohol response (SR) from acquired tolerance in the prediction of drinking outcomes. METHOD 353 undergraduates completed an online survey. SR was assessed using the SRE form and a modified SRE including items assessing global stimulant and sedative effects. The Daily Drinking Questionnaire-Revised (DDQ-R), and the Rutgers Alcohol Problems Index (RAPI) assessed alcohol use and problems, respectively. RESULTS The revised version of the SRE showed good internal consistency and incremental validity. Early SR assessed by the modified SRE was consistently associated with use and problems. Acquired tolerance was significantly related to use and problems above and beyond early SR. CONCLUSIONS The modified SRE incorporating stimulant and sedative responses demonstrated good psychometric properties and the potential to capture unique variability in drinking outcomes. Differentiating early SR from tolerance showed that each contributes uniquely to drinking behavior and problems. Thus, future studies would benefit from examining the unique contribution of each aspect of SR.

The Subjective Effects of Alcohol Scale: Development and Psychometric Evaluation of a Novel Assessment Tool for Measuring Subjective Response to Alcohol

Three decades of research demonstrate that individual differences in subjective response (SR) to acute alcohol effects predict heavy drinking and alcohol-related problems. However, the SR patterns conferring the greatest risk remain under debate. Morean and Corbin (2010) highlighted that extant SR measures commonly have limitations within the following areas: assessment of a comprehensive range of effects, assessment of effects over the complete course of a drinking episode, and/or psychometric validation. Furthermore, the consistent pairing of certain SR measures and theoretical models has made integration of findings difficult. To address these issues, we developed the Subjective Effects of Alcohol Scale (SEAS), a novel, psychometrically sound SR measure for use in alcohol administration studies. Pilot data ensured that the SEAS comprised a comprehensive range of effects that varied in terms of valence and arousal and were perceived as plausible effects of drinking. For validation purposes, the SEAS was included in a 2-site, placebo-controlled, alcohol administration study (N = 215). Exploratory and confirmatory factor analyses identified a 14-item, 4-factor model categorizing effects into affective quadrants (high/low arousal positive; high/low arousal negative). SEAS scores evidenced the following: (a) scalar measurement invariance by limb of the blood alcohol curve (BAC) and beverage condition; (b) good internal consistency; (c) convergence/divergence with extant SR measures, alcohol expectancies, and alcohol use; and (d) concurrent/incremental utility in accounting for alcohol-related outcomes, highlighting the novel high arousal negative and low arousal.

Contingency management improves smoking cessation treatment outcomes among highly impulsive adolescent smokers relative to cognitive behavioral therapy.

BACKGROUND Impulsive adolescents have difficulty quitting smoking. We examined if treatments that provide behavioral incentives for abstinence improve treatment outcomes among impulsive adolescent smokers, who have been shown to be highly sensitive to reward. METHODS We ran secondary data analyses on 64 teen smokers (mean age=16.36 [1.44]; cigarettes/day=13.97 [6.61]; 53.1% female; 90.6% Caucasian) who completed a four-week smoking cessation trial to determine whether impulsive adolescents differentially benefit from receiving cognitive behavioral therapy (CBT), contingency management (CM), or the combination of the two (CM/CBT). Indices of treatment efficacy included self-report percent days abstinent and end of treatment biochemically-confirmed 7-day point prevalence abstinence (EOT abstinence). We assessed self-reported impulsivity using the Brief Barratt Impulsiveness Scale. We used univariate Generalized Linear Modeling to examine main effects and interactions of impulsivity and treatment condition as predictors of self-reported abstinence, and exact logistic regression to examine EOT abstinence. RESULTS CM/CBT and CM were comparably effective in promoting abstinence, so analyses were conducted comparing the efficacy of CBT to treatments with a CM component (i.e., CM and CM/CBT). CBT and deficient self-regulation predicted lower self-reported abstinence rates within the total analytic sample. Treatments containing CM were more effective than CBT in predicting 1) self-reported abstinence among behaviorally impulsive adolescents (% days abstinent: CM 77%; CM/CBT 81%; CBT 30%) and 2) EOT point prevalence abstinence among behaviorally impulsive adolescents and adolescents with significant deficits in self-regulation. CONCLUSION CM-based interventions may improve the low smoking cessation rates previously observed among impulsive adolescent smokers.

Psychometrically Improved, Abbreviated Versions of Three Classic Measures of Impulsivity and Self-Control

Self-reported impulsivity confers risk factor for substance abuse. However, the psychometric properties of many self-report impulsivity measures have been questioned, thereby undermining the interpretability of study findings using these measures. To better understand these measurement limitations and to suggest a path to assessing self-reported impulsivity with greater psychometric stability, we conducted a comprehensive psychometric evaluation of the Barratt Impulsiveness Scale-11 (BIS-11), the Behavioral Inhibition and Activation Scales (BIS/BAS), and the Brief Self-Control Scale (BSCS) using data from 1,449 individuals who participated in substance use research. For each measure, we evaluated (a) latent factor structure, (b) measurement invariance, (c) test-criterion relationships between the measures, and (d) test-criterion relations with drinking and smoking outcomes. Notably, we could not replicate the originally published latent structure for the BIS, BIS/BAS, or BSCS or any previously published alternative factor structure (English language). Using exploratory and confirmatory factor analysis, we identified psychometrically improved, abbreviated versions of each measure: 8-item, 2-factor BIS-11 (root-mean-square error of approximation [RMSEA] = .06, comparative fit index [CFI] = .95); 13-item, 4-factor BIS/BAS (RMSEA = .04, CFI = .96); and 7-item, 2-factor BSCS (RMSEA = .05, CFI = .96). These versions evidenced (a) stable, replicable factor structures, (b) scalar measurement invariance, ensuring our ability to make statistically interpretable comparisons across subgroups of interest (e.g., sex, race, drinking/smoking status), and (c) test-criterion relationships with each other and with drinking/smoking. This study provides strong support for using these psychometrically improved impulsivity measures, which improve data quality directly through better scale properties and indirectly through reducing response burden.

The Anticipated Effects of Alcohol Scale: development and psychometric evaluation of a novel assessment tool for measuring alcohol expectancies.

Alcohol expectancy (AEs) research has enhanced our understanding of how anticipated alcohol effects confer risk for heavy drinking and alcohol-related problems. However, extant AE measures have limitations within 1 or more of the following areas: assessing a comprehensive range of effects, specifying the hypothetical number of drinks consumed, assessing AEs by limb of the blood alcohol curve (BAC), and/or not having undergone psychometric evaluation. Building upon the strengths of existing measures, we employed conceptual and statistical advances in measurement development to create the novel, psychometrically sound Anticipated Effects of Alcohol Scale (AEAS). Unique to this study, pilot data ensured that the AEAS comprised a comprehensive sampling of effects that varied in valence (positive/negative) and arousal (low/high) and were identified as plausible outcomes of drinking. The AEAS specified the number of drinks individuals imagined consuming (adjusted for sex) and the hypothetical drinking episode length (2 hr). AEs were also assessed separately by BAC limb. For validation purposes, the AEAS was included in several survey studies of young adults (ages 18-30). The validity argument for the proposed interpretation of AEAS test scores was based upon the following: (a) exploratory and confirmatory factor analyses (N = 546) identified a 22-item, 4-factor internal structure, categorizing alcohol effects into quadrants (high/low arousal crossed with positive/negative valence); (b) scalar measurement invariance was established for BAC limb, sex, and binge drinking status; (c) convergence/divergence was observed with alternative AEs measures and mood; and (d) test-criterion relationships were observed with several alcohol-related outcomes. The reliability argument was based on test-retest and internal consistency coefficients.