Application of an alcohol clamp paradigm to examine inhibitory control, subjective responses, and acute tolerance in late adolescence

Abstract

Individual differences in acute alcohol effects on cognitive control and subjective responses--and acute tolerance to these effects--are implicated in the risk for heavy drinking and alcohol-related harms. Few studies have examined these effects in drinkers under age 21. Additionally, studies of acute tolerance typically involve bolus oral alcohol administration, such that estimates of tolerance are confounded with blood alcohol concentration (BAC) limb. The current study examined cognitive control and subjective responses in young heavy drinkers (n = 88; M = 19.8 years old, SD = 0.8) during a single-session alcohol clamp protocol. Participants completed an intravenous alcohol session comprising an ascending limb (0 to 80 mg% in 20 min) and a BAC plateau (80 mg% for 80 min). Serial assessments included a cued go/no-go task and measures of stimulation, sedation, and craving. Relevant individual difference factors (attention-deficit hyperactivity disorder [ADHD] symptoms and sensation seeking) were examined as moderators. Multilevel modeling demonstrated that response inhibition worsened following initial rise in BAC and showed increasing impairment during the BAC plateau. ADHD symptoms and sensation seeking moderated this effect. Significant within-person associations between stimulation and craving were evident on the ascending limb only. Participants with higher ADHD symptoms reported steeper increases in stimulation during the ascending limb. These findings provide initial information about subjective and behavioral responses during pseudoconstant BAC, and potential moderators of these outcomes, in late adolescence. Additional studies with placebo-controlled designs are necessary to confirm these findings.

Figure 1

Observed breath alcohol concentrations (BrACs) prior to each administration of the go/no-go task and subjective questionnaires during the alcohol infusion. G= go/no-go time point; S=Subjective questionnaire time point. Standard errors shown in error bars.

Figure 2

Main effects of time point on (a) inhibition failures (proportion) on the go/no-go task, (b) Go reaction time (RT) to go cues in ms (i.e., Response Activation), (c) subjective stimulant and sedative effects, and (d) craving. Markers and error bars represent observed means and standard errors. Subjective questionnaire scores were re-scaled to a 0-10 scale for analysis. G= Go/no-go time point; S=Subjective questionnaire time point. Times (mins) in parentheses on the x-axis represent approximate time elapsed since the start of the infusion.

Figure 3

Simple slopes for changes in inhibition failures conditioned on high (1SD above mean) and low (1SD below mean) levels of (a) ADHD symptoms and (b) sensation seeking, and simple slopes for changes in subjective stimulation conditioned on high and low levels of ADHD symptoms (c). Subjective stimulation scores were re-scaled to a 0-10 scale for analysis.