Regulation of Affect and Physiology in Depression

Although treatments for depression are effective for many people, not everyone responds to treatment. This lack of treatment response could be due, in part, to the presence of multiple underlying causes of people's depression. This study aims to identify subtypes of depression, based on two factors: how successful people perceive themselves to be at regulating their affect in everyday life; and how much activity in the parasympathetic nervous system increases during moments when people try to regulate. The study involves ambulatory assessment of affect, regulation strategies, and physiological activity in everyday life, in a sample of young adults with remitted major depressive disorder and healthy volunteers. We will study regulation responses in the lab to further determine how subtypes differ in neural, physiological, and behavioral responses. Finally, participants will be randomly assigned to a remote, self-administered biofeedback intervention (vs. control intervention) designed to increase parasympathetic activity and physiological regulation success. While engaging in biofeedback at home for 10 days, participants will simultaneously repeat the ambulatory assessments. This design will allow us to determine the proximal impact of biofeedback on indices of regulation success in everyday life, and whether biofeedback has differential impact on regulation success for different subtypes.

NCT Number	NCT06345859
Lead Sponsor	University of Southern California Collaborators: National Institute of Mental Health (NIMH)
Conditions	Major Depressive Disorder
Enrollment	252 participants
Start Date	2024-03-22
Primary Completion	2028-04-30 (estimated)
Study Completion	2028-05-31 (estimated)
Updated on ClinicalTrials.gov	2026-05-04