How people decide to consume (more) alcohol when feeling stressed.

BACKGROUND AND

aimsThe tension reduction hypothesis suggests that people consume alcohol to alleviate stress. While previous studies showed stress increases alcohol's absolute value, alcohol's value relative to alternatives should be more relevant for drinking decisions. We aimed to test whether acute stress causes individuals to choose alcohol over appealing non-alcoholic alternatives and to identify the cognitive mechanisms underlying this choice behavior.

designLaboratory-based randomized 2 × 2 experimental study.

settingControlled laboratory environment including a simulated bar setting.

participants160 adults [56% male; mean age = 31 years; median Alcohol Use Disorders Identification Test (AUDIT) score = 8] who regularly consume alcohol.

interventionsParticipants first rated beverages and made repeated choices between alcoholic and non-alcoholic options. They then received either alcoholic beverages [target breath alcohol concentration (BrAC) = 0.06%] or non-alcoholic beverages, followed by either a personalized stress induction using autobiographical emotional memories or a neutral control procedure. MEASUREMENTS: Primary outcomes were proportion of choices for alcoholic beverages and decision response times. Choice behavior was analyzed using drift diffusion modeling to decompose decisions into three mechanisms: decision carefulness (boundary parameter), sensitivity to prior preferences (drift rate) and bias toward alcohol regardless of preference (bias parameter).

findingsStress moderately increased choices for alcohol [95% highest density interval (HDI) = 0.01-0.13], but only in sober participants. Drift diffusion modeling revealed that stress primarily affected decision-making by inducing a bias toward alcohol during evidence accumulation (95% HDI = 0.19-0.76), without impacting decision carefulness or evidence sensitivity. This computational bias was stronger than observed in raw choice behavior, indicating that while stress consistently biased evaluation toward alcohol, this bias only sometimes overcame competing considerations (i.e. a person might reverse a preference from 'a little bit' to 'not really', but not from 'a little bit' to 'not at all').

conclusionsOur results support the tension reduction hypothesis by demonstrating that stress occasionally led individuals to choose alcohol even when they preferred the non-alcoholic alternative; however, this effect only appeared in sober participants who had not yet consumed any alcohol, suggesting the hypothesis primarily explains decisions about initiating rather than continuing drinking episodes.