UTMB research proposes new way to understand addiction

Why does a person continue seeking drugs when doing so becomes increasingly difficult, frustrating, or harmful?

Researchers at The University of Texas Medical Branch (UTMB) are proposing that part of the answer may involve a breakdown in a natural behavioral "brake" that normally signals when it is time to stop pursuing a goal.

In a paper published in Frontiers in Psychiatry, UTMB researchers introduce the "frustration brake failure" hypothesis, which suggests frustration may play an important role in substance use disorders alongside craving, impulsivity, and habit.

The concept starts with a familiar experience: When people pursue something they want and encounter an obstacle, frustration can initially make them try harder. But as obstacles mount and success becomes less likely, frustration normally begins to reduce motivation. Eventually, most people decide the reward is no longer worth the effort and stop trying.

Thomas Green, PhD, a professor in the UTMB Department of Pharmacology and Toxicology, and his colleagues propose that repeated drug use may disrupt that relationship between frustration and motivation in some people with substance use disorders. The frustration remains, but its ability to reduce motivation and stop drug-seeking behavior may become weakened.

The researchers emphasize that the paper presents a hypothesis rather than identifying a specific "frustration brake" in the human brain. Instead, they hope formally defining the concept will encourage researchers to investigate the brain mechanisms that connect frustration, motivation, and drug-seeking behavior.

"Historically, addiction research has focused on understanding how repeated drug use disrupts the reward system to produce intense cravings, impulsive behavior, and habitual drug seeking," said Yorkiris Mármol Contreras, a third-year Biomedical Science doctoral student and lead author of the paper. "But little research considers how frustration, a biological 'stop' signal, fails to do its job in individuals with severe substance use disorders."

The frustration brake hypothesis does not replace traditional explanations. Instead, it proposes an additional mechanism that may help explain why some people continue pursuing drugs even as the associated effort, obstacles, and negative consequences increase.

That possibility also raises an important question for treatment: Could the connection between frustration and motivation be restored?

The authors say the goal of proposing the hypothesis is to encourage research into new therapeutic strategies aimed at "recoupling frustration to motivation" so that increasing frustration once again helps curb drug-seeking behavior.

The researchers point to several interconnected areas of the brain involved in reward, motivation, and responses to frustration as areas for future study. Research will be needed to determine whether the proposed mechanism exists, how repeated drug use might alter it, and whether those changes can be reversed.

If supported by future research, the hypothesis could add another piece to scientists' understanding of why substance use disorders can be so difficult to overcome and potentially identify a new target for treatment.

Additional UTMB researchers involved in this study: Rocio Sanchez Rivas, Shaina Banh, Iona C. Duncan, and Sindhuja Earagolla.