The Effects of Placebo and Moderate Dose Alcohol on Attentional Bias, Inhibitory Control and Subjective Craving

Abstract

Aims Previous research indicates that acute alcohol intoxication and placebo can inhibit people’s control over consumption behaviour and heighten attentional bias (AB) towards alcohol-related stimuli and craving. We designed a study to disentangle anticipated from pharmacological effects of alcohol in order to gain a clearer view of their relative contributions to alcohol consumption. Methods In a within-participants design (moderate alcohol dose, placebo and control), and over a minimum 2-week period, participants completed a battery of questionnaires and cognitive tasks, followed by a bogus taste task to measure ad libitum consumption. Results Both alcohol preload and placebo resulted in cognitive and psychological changes, including impaired inhibitory control, heightened AB and craving. However, ad libitum consumption only increased following alcohol and not placebo. Furthermore, inhibitory control impairments did not mediate the relationship between initial intoxication and ad libitum consumption, and findings indicate that increases in craving may mediate this association. Conclusion Psychological processes such as craving may be more important in driving consummatory behaviour relative to transient changes in cognitive processes, such as inhibitory control.

Intoxication without anticipation: Disentangling pharmacological from expected effects of alcohol

“…Specifically, elevated ad libitum consumption was only evident in the pharmacological conditions (in the alcohol aware and blind conditions), suggesting anticipation does not exert an influence on continued consumption. This is consistent with research findings which show heightened consumption following alcohol, but not placebo (Christiansen et al, 2013;McNeill et al, 2021) and, to our knowledge, only one comparable study finding heightened consumption following placebo (Chirstiansen et al, 2017). Current findings from the alcohol blind beverage condition suggest that in the absence of anticipation, ad libitum consumption was akin to that observed in the traditional alcohol aware condition (where there is both the impact of pharmacology with anticipation).…”

“…Rather, craving appeared to emerge as a more central influence on the initiation and maintenance of drinking, indicated by the partial mediatory association between initial intoxication and ad libitum consumption. This extends previous work indicating that transient impairments in inhibitory control are not directly associated with heightened consumption (McNeill et al, 2018(McNeill et al, , 2021 and that implementation intentions and craving appear to supersede daily fluctuations in inhibitory control in predicting drinking episodes (Jones et al, 2018). Overall, there therefore appears to be a growing convergence of evidence to support the assertion that successive consumption may be driven primarily by the pharmacological effects of alcohol which are exerted via changes in craving.…”

“…These findings were not unexpected and are observed in the literature (e.g. McNeill et al, 2021). However, the administration of alcohol by deception (in the absence of anticipation -the alcohol blind condition) appears to shed new light on the relative contributions of anticipation and pharmacology where inhibitory control and craving are concerned.…”

“…Specifically, findings by Monem and Fillmore (2019) indicate that AB for alcohol-related stimuli shows dose-dependent decreases; however, the same pattern of decreases was not observed for other appetitive stimuli. These findings are also consistent with those suggestive of elevated AB following placebo (McNeill et al, 2021). However, they are inconsistent with the notion that elevated levels of craving should be associated with heightened AB (e.g.…”

“…Research has established that both the pharmacological effects of intoxication and the psychologically anticipated effects of alcohol consumption impact alcohol behaviours in important ways. For example, low doses of alcohol have been found to increase subsequent consumption (Fernie et al, 2012), possibly by impairing inhibitory control mechanisms (Weafer & Fillmore, 2016) or by eliciting craving (McNeill et al, 2021). It is also established that psychosocially negotiated expectations about one's own and others' alcohol behaviours (McAndrew & Edgerton, 1969) and related cognitions (Marlatt et al, 1973) can exert significant influences on alcohol behaviours (Christiansen et al, 2017).…”