All in the mind? The effect of beliefs about alcohol on alcohol binges Mr Graeme Knibb

Alcohol Priming Effect Acute doses of alcohol promote alcohol seeking behaviour e.g. craving and ad lib alcohol consumption (de Wit et al, 1993). May underlie binge drinking (Field et al, 2008). Mechanisms driving this process are relatively unknown.

Inhibitory Control The ability to inhibit a pre potent response (Verbruggen & Logan, 2009). Inhibitory control reliably impaired by alcohol (e.g. de Wit et al, 2000).

Inhibitory Control The ability to inhibit a pre potent response (Verbruggen & Logan, 2009). Inhibitory control reliably impaired by alcohol (e.g. de Wit et al, 2000).

Inhibitory Control The ability to inhibit a pre potent response (Verbruggen & Logan, 2009). Inhibitory control reliably impaired by alcohol (e.g. de Wit et al, 2000).

Inhibitory control Alcohol-induced impairments of inhibitory control may mediate the alcohol priming effect (Weafer & Fillmore, 2008). Contrary findings (Christiansen et al, 2013). Impaired inhibitory control e.g. de wit et al (2000 ) ?

Expectancies Placebo drinks can also increase craving and ad lib alcohol consumption (e.g. Marlatt et al, 1973; Christiansen et al, 2013). Placebo drinks can cause impairments in inhibitory control, with this effect being greatest in those who expect cognitive impairment when they drink (Christiansen et al., 2016). Alcohol-induced impairments can be reversed by paying participants (Fillmore & Vogel-Sprott, 1994). Beliefs about ability to control behaviour are important determinants of successful behavioural regulation (Clarkson et al, 2010; Job et al, 2010).

Hypotheses Lack of control over drinking, following an initial drink, may be influenced by the extent people believe their self-control has been reduced by alcohol. Participants led to believe that consuming an acute dose of alcohol will reduce their urge to drink will consume less alcohol. The effect of alcohol on inhibitory control will be mediated by expectancies rather than the pharmacological effects of alcohol.

Method 81 social drinkers Two sessions – Placebo – Alcohol (.5g/kg). Bar laboratory

Scripts Neutral “Our research has been investigating the effects of alcohol on thought processes like memory, problem solving and attention. …alcohol has a greater effect on some of these processes than others. This final experiment is testing the effects of alcohol on simple reaction times and taste perception.” Experimental “Our research has found that consuming alcohol reduces the body’s urge to drink … Furthermore… consuming large amounts of alcohol as part of an unplanned binge is a cultural phenomenon … Other European countries involved in our research program have not found that consuming alcohol leads to further alcohol consumption.”

Baseline questionnaires Exposed to script (Neutral or Experimental) Reminder in Session 2 Priming Procedure (placebo/alcohol.5g/kg) Stop-signal task Bogus taste task

Questionnaires Craving & Subjective intoxication  Desire for Alcohol Questionnaires(DAQ)  Subjective Intoxication Scales (SIS)  Baseline, post-prime, pre-adlib.

Data Reduction Removed all participants who stated placebo drink contained 0 units. Removed extreme SSRT outliers. 59 remaining (33 female).

Results: Characteristics MANOVA revealed no sig main effect of condition on baseline characteristics (p=.94). ExperimentalNeutralOverall AUDIT11.82(±4.37)12.42(±4.33)12.14(±4.32) TLFB47.66(±20.98)46.05(±17.79)46.81(±19.22) LDS4.48(±4.64)5.81(±4.13)5.19(±4.38) Age27.20(±9.22)25.17(±7.62)26.23(±8.47)

Results: Craving & Drinking Increased craving following alcohol relative to placebo; p=.001, n P 2 =.19. But baseline differences. No effect of drink or condition on ad lib alcohol consumption.

Results: Inhibitory control Main effect of Script p=.018, n p 2 =.10

Discussion Poorer performance on SST following the experimental script may be explained by a reduction in compensatory effects. Participants reduce the amount of effort that they exert during the task as they have been led to believe alcohol will not impair performance.

Discussion Highlights the importance of considering the beliefs about the effects of alcohol when subjecting participants to cognitive tasks. Such beliefs may be a more important determinant of performance on the SST than alcohol consumption.

Limitations No group led to believe alcohol will increase urge to drink. No baseline SSRT. BUT participants were randomly allocated and did not differ on any baseline characteristic (AUDIT, TLFB, LDQ, SIS, Age).

Thank you. Dr Paul Christiansen, Dr Abigail Rose, Dr Eric Robinson, Dr Carl Roberts, Prof Matt Field.