How the Brain Encodes Beliefs: A Functional Magnetic Resonance Imaging Study of the Belief Updating in Treatment Resistant Depression.

What this Trial Is About

Researchers are investigating how the brain processes belief updating in patients with treatment resistant depression (TRD), a condition where negative beliefs about oneself, the future, and the world persist despite evidence to the contrary. This study aims to understand the brain mechanisms behind this difficulty in changing negative beliefs, especially in patients who do not respond to typical antidepressant treatments. The focus is on how ketamine treatment may affect these brain processes and belief updating compared to other antidepressants. The study involves 120 patients with TRD who will be tested twice: once before and once 24 hours after starting a new antidepressant treatment. Sixty patients will receive a ketamine infusion and undergo functional magnetic resonance imaging (fMRI) to observe brain activity related to belief updating. The other 60 patients will be assessed behaviorally after starting monoaminergic antidepressants in their routine clinical care. Participants will complete a cognitive task presenting 40 adverse life events and rate the events on various emotional and personal factors. Throughout the study, clinical measures including depression severity and treatment resistance will be collected by psychiatrists. The primary outcome is the brain's oxygenation signal (BOLD) measured by fMRI, focusing on changes before and after treatment. Secondary outcomes include behavioral measures of belief updating and depression rating scales. The study is observational, conducted in a natural care setting, with assessments occurring within seven days of the first antidepressant dose.

Belief Updating in Treatment Resistant Depression