The Return of Fear in Human Fear Conditioning: Evaluating the Road to Relapse Prevention.

Abstract

In their 2022 mental health report, the World Health Organization estimated that around 374 million people suffer from an anxiety disorder. These disorders do not only constitute a major health problem for patients, but they also have an enormous economic and societal impact. Therefore, it is highly important to develop effective treatments to reduce the suffering and increase the quality of life of these individuals.

Exposure-based therapies have proved to be effective for the treatment of anxiety disorders, with some authors suggesting that they should be considered the first-line treatment. However, although these therapies seem to be effective in the short term, anxiety symptoms can reappear in the long term. Following a translational framework, we can tackle those limitations by modelling exposure therapy in the laboratory by means of investigating fear extinction. This way, we can improve and deepen our understanding of underlying mechanisms, study the reasons behind response recovery (i.e., return of fear phenomena) and the parallelism observed with clinical relapse, and use extinction as a mean to develop new or improve already existing relapse prevention strategies.

This thesis focuses on the study of three extinction strategies aimed at preventing the return of fear using a human fear conditioning paradigm. To do this, we tested their effectiveness to reduce fear recovery and assessed potential explanations regarding the mechanisms supporting their apparent benefit.