Understanding the effects of stress and alcohol cues on motivation for alcohol via behavioral economics

Abstract

Background: Psychological stress and alcohol cues are common antecedents of both ongoing drinking and relapse. One candidate mechanism of risk from these factors is acute increases in craving, but experimental support for this hypothesis is mixed. Furthermore, the combination of stress and cues has been largely unstudied. The current study employed a behavioral economic approach to investigate the combined roles of psychosocial stress and alcohol cues on motivation for alcohol.

Methods: In a sample of 84 adult heavy drinkers, we examined the effects of an acute laboratory stress induction and an alcohol cue exposure on subjective craving and stress, arousal, and behavioral economic decision making. Primary dependent measures included an intertemporal cross-commodity multiple-choice procedure (ICCMCP), incorporating both price and delay elements, an alcohol purchase task (APT), measuring alcohol demand, and a monetary delay discounting task, measuring intertemporal choice.

Results: The stress induction significantly increased stress, craving, and the incentive value of alcohol on the ICCMCP and APT. Stress-related increases in value on the ICCMCP were mediated by increased alcohol demand. Exposure to alcohol cues only significantly affected craving, APT breakpoint, and arousal. Delay discounting was not affected by either stress or cues.

Conclusions: These results reveal unique behavioral economic dimensions of motivation for alcohol following acute stress and an alcohol cue exposure. More broadly, as the first application of this approach to understanding the role of stress in drug motivation, these findings support its utility and potential in future applications.

Keywords: Alcohol; Behavioral Economics; Craving; Incentive Value; Stress.

Figure 1. Relationship between behavioral economic measures

The primary behavioral economic measure—the intertemporal cross-commodity multiple choice procedure (ICCMP)—combined elements of cost and delay into a single assessment. Effects on the ICCMP were further disentangled using the two secondary measures. The alcohol purchase task (APT) and delay discounting task (DDT) examined the influence of alcohol demand and intertemporal choice, respectively. Sample items from each measure are provided.

Figure 2. Schematic diagram of laboratory session components

Assessments are listed in top row, exposures and other key events are listed in middle row, and corresponding time points relative to the start of the session are provided in the bottom row. Random selection and provision of ICCMCP outcome (alcohol or money) occurred following Post-Cues assessment.

Figure 3. Significant effects of acute stress on affect, arousal, craving, and behavioral economic indices

Panel A depicts composite stress ratings; Panel B depicts subjective craving for alcohol; Panels C–D depict physiological arousal (MAP: Mean Arterial Pressure); Panel E depicts crossover point on the intertemporal cross-commodity multiple choice procedure (ICCMP); Panels F–H depict Intensity, Breakpoint and O_max from the alcohol purchase task. Bars reflect mean (+/− standard error). *p<.05; **p<.01.

Figure 4. Effects of alcohol cues on arousal, craving, and alcohol demand

Panel A depicts change in alcohol craving; Panel B depicts change in heart rate; Panel C depicts change in Breakpoint on the alcohol purchase task. Note, in Panel C, the two groups were significantly different at the Post-Stress time point (p = .04). In each panel, solid lines reflect the alcohol cues group; dashed lines reflect the neutral cues group. Data points reflect mean (+/− standard error). **p<.01; ***p<.001.