A Critical Review of Alcohol Administration Guidelines in Laboratory Medication Screening Research: Is It Time to Include Treatment Seekers?

Human laboratory studies play an important role in alcohol use disorder (AUD) medication development. Medications that are found to be safe and effective during human laboratory screening will then move to more expensive clinical trials in patient populations. Given the gatekeeping role of human laboratory studies in the medication development pipeline, it is critical that these studies accurately forecast how pharmacotherapies will perform under true-to-life clinical conditions. On the other hand, the design of these studies also must adhere to ethical guidelines: certain aspects of clinical reality cannot be incorporated into screening studies because doing so might place the participant at risk for harm or breach other ethical guidelines. Conventions exist that guide the resolution of these conflicting ideals. This article considers the practice of recruiting non-treatment-seeking heavy drinkers to participate in laboratory screening studies. By convention, volunteers are excluded from laboratory screening studies that involve alcohol administration if they are deemed "treatment seeking," meaning that they recently stopped drinking or are motivated to do so. Although this common practice may reduce risk to participants, findings may not accurately predict medication effects on treatment seekers. Indeed, there is empirical evidence that treatment seekers differ from nontreatment seekers in their responses to medications (Neuropsychopharmacology 2017a; 42: 1776; Am J Drug Alcohol Abuse 2017b; 43: 703; J Psychiatr Res 2006; 40: 383). Here, we argue for the importance of recruiting treatment seekers for this research due to their qualitative difference from nontreatment seekers. We argue that these individuals should be the default population in human laboratory medication screening studies. We conclude by discussing 2 case examples of medication experiments led by our research groups that involved administering medications to treatment seekers.

Intravenous Alcohol Administration Selectively Decreases Rate of Change in Elasticity of Demand in Individuals With Alcohol Use Disorder

BACKGROUND

Alcohol demand is a key behavioral economic concept that provides an index of alcohol's relative reinforcing value. Initial studies have reported that alcohol demand increases during alcohol administration and in response to alcohol cues. However, the extent to which these effects are observed explicitly in samples composed of individuals with alcohol use disorder (AUD) and are operative in conjunction with each other has not been studied.

METHODS

To address this gap in the literature, we assessed alcohol demand during an alcohol challenge and subsequent alcohol cue-exposure paradigm in non-treatment-seeking, alcohol-dependent (i.e., DSM-IV criteria) participants (N = 27). Specifically, participants completed 2 counterbalanced intravenous, placebo-controlled, alcohol administration sessions followed by a controlled cue-exposure paradigm. At baseline and at breath alcohol concentration of 0.06 g/dl, participants completed the alcohol purchase task, assessing estimated alcohol consumption at escalating prices. Participants were also assessed for alcohol demand following each cue exposure.

RESULTS

During alcohol administration, there was a significant decrease in the rate of change in elasticity compared with placebo, and during the cue-reactivity paradigm, there was a significant main effect such that alcohol cues decreased the rate of change in elasticity relative to water cues. There were no statistically significant differences in other demand indices.

CONCLUSIONS

These findings provide further evidence that alcohol administration increases price insensitivity and extends the literature on alcohol's effects on demand by using a clinical sample with AUD and by adding a placebo-alcohol condition.

Sexual Aggression Analogues Used in Alcohol Administration Research: Critical Review of Their Correspondence to Alcohol-Involved Sexual Assaults

BACKGROUND

Alcohol administration studies are crucial because causal questions about alcohol's role in human behavior can only be answered through experimental research that randomly assigns participants to drink conditions. The primary goal of this review was to catalogue the characteristics of experimental analogues used in alcohol administration research to assess men's sexual aggression proclivity and evaluate the extent to which they represent the scope of alcohol-involved sexual aggression. Although this review focuses on sexual aggression analogues, the identified methodological issues are relevant to a wide range of alcohol administration studies.

METHODS

Online databases were searched for published studies that randomly assigned participants to drink conditions and assessed participants' sexual aggression proclivity with an experimental analogue. Characteristics of the analogues were coded by both authors.

RESULTS

Seventeen studies were identified that used 12 unique experimental analogues. All of the analogues depicted a completed or potential sexual assault in an apartment between a male perpetrator and female victim who did not know each other well. This information was presented in written (n = 7), audio (n = 1), video (n = 3), or virtual simulation (n = 1) format. Sexual aggression proclivity was measured through participants' self-reports (n = 10) and behavioral responses (n = 2). Perpetrators primarily used physical force which the woman verbally and physically resisted. Only one analogue depicted behavioral signs of the woman's alcohol impairment; none included signs of the man's alcohol impairment.

CONCLUSIONS

These analogues were designed to address important theoretical questions; however, they do not represent the full range of alcohol-involved sexual assaults. This hampers the development of evidence-based prevention and treatment programs because we do not know whether these findings generalize to other types of sexual assaults (e.g., with incapacitated victims, within serious relationships, with sexual and other gender minorities). Funding agencies need to support more alcohol administration research in order to provide a strong foundation for the development of effective interventions.

Explicit Attitudes, Working Memory Capacity, and Driving After Drinking

BACKGROUND

Attitudes toward driving after drinking are strongly predictive of drinking and driving behavior. This study tested working memory capacity (WMC) as a moderator of the association between attitudes and drinking and driving behavior. Consistent with dual process models of cognition, we hypothesized that the association between perceived danger and drinking and driving would be stronger for individuals with higher WMC.

METHODS

Participants (N = 161) enrolled in larger alcohol administration study were randomly assigned to an alcohol (n = 57), placebol (n = 52), or control (n = 52, not included) beverage condition. Past-year frequency of driving after drinking and WMC were assessed at baseline. Attitudes were assessed by asking participants to rate the perceived danger of driving at their current level of intoxication twice on the ascending limb (AL1, AL2), at peak breath alcohol concentration (BrAC), and twice on the descending limb (DL1, DL2).

RESULTS

Analyses across the BrAC curve indicated that the hypothesized interaction was observed for the alcohol but not placebo condition. Analyses for each assessment point indicated that the interaction was significant for the ascending limb and peak BrAC. In the alcohol condition, for those higher in WMC, lower perceived dangerousness was strongly associated with increased driving after drinking (AL1: incident rate ratios [IRR] = 5.87, Wald's χ²  = 12.39, p = 0.006, 95% CI [2.19, 15.75]; AL2: IRR = 8.17, Wald's χ²  = 11.39, p = 0.001, 95% CI [2.41, 27.66]; Peak: IRR = 5.11, Wald's χ²  = 9.84, p = 0.002, 95% CI [1.84, 14.16]). Associations were not significant at low WMC.

CONCLUSIONS

Results suggest that individuals higher in WMC are more likely to act consistently with their explicit attitudes toward drinking and driving. Findings may have implications for existing drinking and driving interventions and suggest the potential for novel interventions targeting implicit associations or WMC.

Alcohol Vapor Inhalation as a Model of Alcohol-Induced Organ Disease

BACKGROUND

Chronic intermittent ethanol vapor (CIEV) exposure has been used extensively to produce rodent models of alcohol dependence, but unlike other models of alcohol abuse, CIEV has not been assessed as a model of end-organ damage. The purpose of this study was to characterize the effects of CIEV on peripheral organ systems affected by alcohol abuse, including the liver, lungs, and cardiovascular system.

METHODS

Adult male Sprague-Dawley rats were exposed to daily CIEV for a period of 8 weeks (14HR ON/10HR OFF), producing blood alcohol levels of ~200 mg/dl. Controls were exposed to room air. After 8 weeks, echocardiography was performed to assess cardiac function. Indices of liver injury (alanine and aspartate aminotransferases [ALT and AST]; cytochrome p450 2E1 [CYP2E1]; alcohol dehydrogenase [ADH]; Oil Red O and triglyceride content; lipid peroxidation; inflammatory cytokine expression; and macrophage infiltration), and lung inflammatory cell count, proinflammatory cytokine expression, and lipid peroxidation were measured.

RESULTS

Left ventricular posterior wall thickness was significantly decreased, and systolic blood pressure was significantly elevated by CIEV compared with air controls. CIEV led to a significant increase in plasma ALT and triglycerides compared with room air controls. CIEV did not affect liver triglyceride content, lipid staining or peroxidation, but increased CYP2E1 and chemokine (C-C motif) ligand 2 (CCL2) protein expression, while decreasing ADH expression. CIEV significantly increased numbers of both polymorphonuclear neutrophils and lymphocytes in the bronchoalveolar lavage fluid, indicative of pulmonary inflammation. However, CIEV did not produce significant changes in lung mass, pulmonary lipid peroxidation, inflammatory cytokine expression, or edema.

CONCLUSIONS

These results show that CIEV produces hepatic, pulmonary, and cardiovascular effects in rats similar to those found in other models of chronic alcohol administration. Alcohol vapor administration is a novel method of alcohol-induced tissue injury with high potential for widespread use in alcohol toxicology research.

Perceived danger while intoxicated uniquely contributes to driving after drinking

BACKGROUND

Previous findings suggest that alcohol alters perceptions of risky behaviors such as drinking and driving. However, studies testing these perceptions as a predictor of drinking and driving typically measure these perceptions while participants are sober. This study tested whether the perceived danger of driving after drinking assessed while intoxicated was associated with increased willingness to drive and self-reported drinking-and-driving behavior over and above perceptions assessed while sober. Additionally, we tested the effect of acute tolerance on the perceived danger of driving after drinking assessed on the ascending and descending limbs of the breath alcohol concentration (BrAC) curve.

METHODS

Eighty-two young adults attended 2 counterbalanced laboratory sessions. In one session, participants consumed a moderate dose of alcohol (men: 0.72 g/kg, women: 0.65 g/kg) and reported their perceived danger of driving and willingness to drive at multiple points across the BrAC curve. On a separate occasion, participants remained sober and appraised the dangerousness of driving at a hypothetical, illegal BrAC.

RESULTS

Perceptions of the dangerousness of driving following alcohol administration were associated with increased willingness to drive and higher rates of self-reported drinking-and-driving behavior over and above perceptions reported when sober. Furthermore, perceived danger was reduced on the descending limb of the BrAC curve, compared with the ascending limb, suggesting the occurrence of acute tolerance.

CONCLUSIONS

Results from this study suggest that intoxicated perceptions are uniquely associated with drinking-and-driving decisions and that the perceived danger of drinking and driving is lower on the descending limb of the BrAC curve. Efforts to prevent alcohol-impaired driving have focused on increasing awareness of the danger of driving after drinking. Prevention efforts may be enhanced by educating drivers about how intoxication can alter perceived danger, and interventions may benefit from targeting perceptions of dangerousness while individuals are intoxicated in addition to when they are sober.