Raising the bar: improving methodological rigour in cognitive alcohol research

Changes of attentional bias in patients with alcohol use disorder during abstinence: A longitudinal study

BACKGROUND

Alcohol Use Disorder (AUD) is linked to an attentional bias towards alcohol-related cues (e.g. images, smells), which acquire incentive properties and promote continued consumption.

METHOD

We investigated how the general and alcohol attentional bias evolved longitudinally in AUD patients along two periods of abstinence: t = 0 (baseline, 1-3 months of abstinence) and t = 1 (follow-up; 6 months of abstinence), as well as their relationship with alcohol-related variables. General and alcohol-specific attentional bias were evaluated by the Classic and the Alcohol Stroop tests (neutral and alcohol conditions) in abstinent AUD patients and controls.

RESULTS

At t = 0, the AUD group exhibited both general and alcohol-specific attentional biases, with greater effect in the general bias. At t = 1, alcohol-specific attentional bias decreased specifically in the AUD group and reached control levels (with interference index levels increasing from 1-3 months to 6 months). However, general attentional bias showed a trend toward improvement but it did not significantly change through abstinence process (linear mixed models, controlling for age, BMI, sex and education).

CONCLUSIONS

In AUD patients, general and alcohol attentional biases exhibit different trajectories during abstinence, with the attentional bias toward alcohol improving significantly throughout this process whereas general attentional bias is maintained.

Craving modulates attentional bias towards alcohol in severe alcohol use disorder: An eye-tracking study

BACKGROUND AND AIMS

Competing models disagree on three theoretical questions regarding alcohol-related attentional bias (AB), a key process in severe alcohol use disorder (SAUD): (1) is AB more of a trait (fixed, associated with alcohol use severity) or state (fluid, associated with momentary craving states) characteristic of SAUD; (2) does AB purely reflect the over-activation of the reflexive/reward system or is it also influenced by the activity of the reflective/control system and (3) does AB rely upon early or later processing stages? We addressed these issues by investigating the time-course of AB and its modulation by subjective craving and cognitive load in SAUD.

DESIGN

A free-viewing eye-tracking task, presenting pictures of alcoholic and non-alcoholic beverages, combined with a concurrent cognitive task with three difficulty levels.

SETTING

A laboratory setting in the detoxification units of three Belgian hospitals.

PARTICIPANTS

We included 30 patients with SAUD self-reporting craving at testing time, 30 patients with SAUD reporting a total absence of craving and 30 controls matched on sex and age. All participants from SAUD groups met the DSM-5 criteria for SAUD.

MEASUREMENTS

We assessed AB through early and late eye-tracking indices. We evaluated the modulation of AB by craving (comparison between patients with/without craving) and cognitive load (variation of AB with the difficulty level of the concurrent task).

FINDINGS

Dwell time measure indicated that SAUD patients with craving allocated more attention towards alcohol-related stimuli than patients without craving (P < 0.001, d = 1.093), resulting in opposite approach/avoidance AB according to craving presence/absence. SAUD patients without craving showed a stronger avoidance AB than controls (P = 0.003, d = 0.806). AB did not vary according to cognitive load (P = 0.962, η2 p  = 0.004).

CONCLUSIONS

The direction of alcohol-related attentional bias (approach/avoidance) appears to be determined by patients' subjective craving at testing time and does not function as a stable trait of severe alcohol use disorder. Alcohol-related attentional bias appears to rely on later/controlled attentional stages but is not modulated by the saturation of the reflective/control system.

In people who drink more, facets of theory of mind may be impaired by alcohol stimuli

BACKGROUND

Theory of mind (ToM) - the ability to understand others' beliefs, mental states, and knowledge - is an important part of successful social interaction. There is a growing (albeit mixed) evidence base suggesting that individuals with substance use disorder or who are intoxicated (relative to sober controls) perform worse on a number of ToM tasks. The aim of this study was to explore the hitherto little explored notion that ToM-related capabilities such as the ability to see the world from another person's perspective (termed Visual Perspective Taking; VPT), may be impacted by alcohol-related stimuli.

METHOD

In this pre-registered study, 108 participants (M age = 25.75, SD age = 5.67) completed a revised version of the director task where they followed the instructions of an avatar to move both alcohol beverages and soft drinks that were mutually visible (target objects) while avoiding those only visible to the participant (distractor items).

RESULTS

Contrary to predictions, accuracy was lower when the target drink was alcohol and the distractor was a soft drink, although higher AUDIT scores were associated with significantly lower accuracy when alcohol drinks were the distractor items.

CONCLUSIONS

There may be some contexts when being able to see alcohol beverages makes it harder to take another person's perspective. It also appears that poorer VPT and perhaps ToM capacity may be evident in individuals who consume more alcohol. Future research is warranted to examine how alcohol beverages, alcohol consumption behaviours, and intoxication interact to impact VPT capacity.

How laboratory studies of cigarette craving can inform the experimental alcohol craving literature

Interest in alcohol and other drug craving has flourished over the past two decades, and evidence has accumulated showing that craving can be meaningfully linked to both drug use and relapse. Considerable human experimental alcohol craving research since 2000 has focused on craving as a clinical phenomenon. Self-reported craving to drink typically has served as a catch-all for the craving construct in these studies, whereas few studies have considered craving as a process (or hypothetical construct) that interacts with other phenomena to affect use. In contrast to alcohol, we believe that recently there has been more mechanistic work targeting cigarette craving-related processes. Here, we briefly present a narrative review of studies of acute alcohol craving in humans that have been conducted during the past two decades. We then specify important ways in which alcohol and tobacco differ (e.g., the role of withdrawal), and we note the unique challenges in inducing robust alcohol craving states in the laboratory. Finally, we offer recommendations for how the alcohol field might advance its conceptual understanding of craving by adopting ideas and methods drawn from the smoking research literature. Specifically, we suggest that researchers extend their studies to not only examine the link between alcohol craving and relapse but also to focus on why and, in some instances, how alcohol cravings matter clinically, and the circumstances under which craving especially matters. We propose research to investigate the shifts in alcohol-related cognitive and affective processing that occur during alcohol craving states. Furthermore, we highlight the value of research examining the level of insight that individuals with varying levels of alcohol involvement possess about their own craving-related processing shifts. We believe that laboratory studies can provide rich opportunities to examine conceptual questions about alcohol craving that are central to addiction.

Intoxication without anticipation: Disentangling pharmacological from expected effects of alcohol

BACKGROUND

The pharmacological effects of alcohol on executive function, craving and subsequent alcohol-seeking have been well documented. Yet, insufficient methodological controls within existing alcohol administration paradigms have meant that the relative importance of alcohol's pharmacological and anticipatory effects remains in need of further elucidation.

AIM

The objective of this study is to disentangle alcohol's pharmacological effects from its anticipatory effects on alcohol-related cognitions and subsequent consumption.

METHODS

Inhibitory control, attentional bias and craving were assessed pre- and post-consumption in 100 participants who were randomly allocated to one of four beverage conditions in a two by two design: (1) alcohol aware (alcohol with participant knowledge (pharmacological/anticipation effects)), (2) alcohol blind (alcohol without participant knowledge; in a novel grain alcohol masking condition (pharmacological/no anticipation effects)), (3) placebo (no alcohol but participants were deceived (anticipation/non-pharmacological effects)) and (4) pure control (no alcohol with participant knowledge (no anticipation/non-pharmacological effects)).

RESULTS

Findings suggest that the pharmacological effects of alcohol result in greater inhibitory control impairments compared with anticipated effects. Anticipatory but not the pharmacological effects of alcohol were found to increase attentional bias. Both pharmacology and anticipation resulted in increased craving, though higher levels of craving were observed due to alcohol's pharmacology. Furthermore, alcohol pharmacology resulted in heightened ad libitum consumption; however, anticipation did not. Changes in craving partially mediated the relationship between initial intoxication and subsequent drinking, while inhibitory control impairments did not.

CONCLUSIONS

Successive alcohol consumption appears driven primarily by the pharmacological effects of alcohol which are exerted via changes in craving.