UCLA

This dissertation comprises three studies aiming to evaluate the relationship between anhedonia and safety learning. Study 1 asks if anhedonia, over and above other symptom dimensions, is associated with distinct patterns of brain activity during fear extinction. Study 2 asks if anhedonia, or the brain patterns associated with anhedonia, is further related to self-reported or physiological indices of Pavlovian fear learning. Study 3 asks if low positive affect, a core feature of anhedonia, is associated with aberrant prediction error during exposure therapy for social anxiety disorder. Taken together, these studies aim to generate a clearer understanding of associations between anhedonia and fear extinction to inform future innovations in the treatment of anxiety and depression. If symptoms of anhedonia are associated with deficits in behavioral and biological indices of fear extinction, such deficits may impact the learning mechanisms central to the efficacy of exposure-based treatments for anxiety disorders.