Alcohol use disorder (AUD) is among the most widespread substance use disorders (SUDs) worldwide, characterized by an impaired ability to control the intake of alcohol. For many years, psychologists and psychiatrists have linked this disorder with a shift away from so-called goal-directed behaviors.
Goal-directed, or model-based, behaviors are those behaviors that are guided by learned mental models of actions and their consequences. Individuals with AUD and other disorders that entail the uncontrolled use of substances have often been hypothesized to engage more in model-free (i.e., habit-driven behavior) than goal-directed behaviors.
Interestingly, however, past studies did not always find evidence supporting this hypothesis. In contrast, some findings suggest that some drinking patterns are in fact associated with goal-directed behavior.
Researchers at the NeuroCure Clinical Research Center, Humboldt University of Berlin and other institutes in Germany recently carried out a study aimed at further exploring the link between AUD and goal-directed behavior, specifically focusing on the neural signatures of this type of behavior. Their findings, published in Translational Psychiatry, suggest that model-based behaviors and their associated neural signatures are linked to a greater control over the consumption of alcohol.
“A shift away from goal-directed, model-based behavior is commonly viewed to characterize AUD,” Claudia Ebrahimi, Milena P.M. Musial and their colleagues wrote in their paper.
“Previous research, however, has failed to demonstrate differences between individuals with and without AUD regarding goal-directed control, operationalized as model-based behavior. Instead, findings suggest associations between model-based behavior and alcohol consumption patterns, but mechanistic insights into the link between model-based behavioral and neural signatures and longitudinal, real-life control over alcohol intake remain elusive.”
Exploring the real-life impact of drinking intentions
To perform their experiments, the researchers recruited 67 individuals diagnosed with AUD, 20 of whom were women. The study participants were asked to complete a task that assessed how they made decisions.
As they completed this task, the team recorded activity in their brain, particularly in two regions known as the hippocampus and ventral striatum, using functional magnetic resonance imaging (fMRI). This is a widely used and noninvasive imaging technique that measures activity in specific brain regions by detecting changes in blood flow and oxygen levels.
The participants were then asked to honestly record how much alcohol they consumed daily and how much they intended to consume on a weekly basis, via a dedicated smartphone-delivered survey. Their smartphone survey responses spanned across an average of 272 days.
“We investigated whether experimentally assessed model-based behavior can prospectively predict intentional reduction of alcohol consumption in daily life,” wrote the authors.
“We related behavioral and neural markers of model-based behavior during a sequential decision-making task in participants with AUD to long-term smartphone-based ecological momentary assessments of daily alcohol intake and weekly alcohol consumption intentions over a period of up to one year.”
Activity patterns linked with better drinking control
Overall, the researchers found that people who were more guided by a model-based pattern of behavior were more likely to successfully limit their drinking if they intended to do so. In addition, they uncovered activity patterns in the hippocampus and ventral striatum that predicted a greater control over drinking behaviors.
“Model-based behavior and its neural signatures in bilateral hippocampus and ventral striatum moderated how well individuals succeeded in aligning their alcohol consumption with their drinking intentions during the following year,” wrote the authors.
“Specifically, AUD participants with higher model-based behavior and associated stronger hippocampal and weaker ventral striatal learning signals exhibited enhanced capacity to intentionally reduce their alcohol consumption in everyday life. These findings provide evidence for the ecological validity of computational concepts of goal-directed behavior and suggest specific treatment targets for individually tailored interventions to regain control over alcohol use.”
Ebrahimi, Musial and their colleagues gathered valuable new insight that could help to improve existing psychological models of AUD. In the future, their findings could pave the way for various follow-up studies, while also potentially informing the development of new personalized interventions aimed at reducing the consumption of alcohol or limiting the uncontrolled consumption of other substances.