Goal-Directed and Habitual Control in Human Substance Use: State of the Art and Future Directions

Theories of addiction posit a deficit in goal-directed behavior and an increased propensity toward habitual actions in individuals with substance use disorders. Control over drug intake is assumed to shift from goal-directed to automatic or habitual motivation as the disorder progresses. Several diagnostic criteria reflect the inability to pursue goals regarding reducing or controlling drug use and performing social or occupational functions. The current review gives an overview of the mechanisms underlying the goal-directed and habitual systems in humans, and the existing paradigms that aim to evaluate them. We further summarize the current state of research on habitual and goal-directed functioning in individuals with substance use disorders. Current evidence of alterations in addiction and substance use are mixed and need further investigation. Increased habitual responding has been observed in more severely affected groups with contingency degradation and some outcome devaluation tasks. Reduced model-based behavior has been mainly observed in alcohol use disorder and related to treatment outcomes. Motor sequence learning tasks might provide a promising new approach to examine the development of habitual behavior. In the final part of the review, we discuss possible implications and further developments regarding the influence of contextual factors, such as state and trait variations, and recent advances in task design. (C) 2022 The Author(s). Published by S. Karger AG, Basel

Automated summary

This article provides an overview of the mechanisms underlying goal-directed and habitual behavior in individuals with substance use disorders and summarizes the current state of research on this topic. The evidence regarding alterations in addiction and substance use is mixed and requires further investigation. Increased habitual responding is observed in more severely affected groups, while reduced model-based behavior is mainly observed in alcohol use disorder.