Explore/exploit decision-making is a crucial component of motivated behavior. Explore/exploit behaviors are related to disparate cognitive and reward-related functions and have been implicated in multiple neuropsychiatric conditions, including major depressive disorder (MDD). Several mediators of explore/exploit decision-making have been proposed; metabolic mechanisms have been theorized to potentially affect its underlying processes. Here, we examined the effects of a GLP-1 receptor agonist (GLP-1RA), semaglutide, on explore/exploit behavior in patients with MDD, using a four-armed restless bandit task.

In this secondary analysis of a randomized clinical trial, 72 participants with MDD were randomized either to oral semaglutide (n = 35) or placebo (n = 37), and completed the bandit task at baseline and following 16 weeks of treatment. Explore/exploit decision-making was assessed using computational modeling of choice behavior, with a trial-by-trial reinforcement-learning model.

Treatment with semaglutide resulted in increased exploitation (i.e. choosing the option with the highest expected reward) (Average Treatment Effect [ATE] = 0.0242, p < 0.001), directed exploration (i.e. exploring a choice with higher uncertainty) (ATE = 0.0619, p = 0.013), and perseveration (i.e. the value-independent tendency to repeat the previous action) (ATE = 0.3017, p = 0.013). These effects were moderated by, but ultimately independent of, baseline characteristics and weight loss during the trial.

Treatment with semaglutide modulated explore/exploit behaviors in patients with MDD. These results highlight the role of metabolic mechanisms in decision-making processes in MDD and expand knowledge of the potential neuropsychiatric effects of GLP-1RAs.