Study of Lorazepam Effects on Brain and Startle Responses in Adults with Depression, Anxiety, or Both Conditions

What this Trial Is About

Researchers are studying how the brain processes threats in people with depression, anxiety disorders, and those who have both conditions together. The study focuses on understanding differences in threat sensitivity by using brain imaging and an anti-anxiety drug called Lorazepam. Participants are grouped by diagnosis those with major depressive disorder and at least one anxiety disorder, those with major depressive disorder alone, and those with anxiety disorder alone. The aim is to learn if these groups respond differently to threats and to the medication. Participants will receive a single dose of 1mg Lorazepam and a placebo in a randomized order during two separate sessions. Each session lasts about 5 hours and includes a startle response test and a functional MRI brain scan to measure brain activity related to threat processing. Before the experimental sessions, a screening session lasting about 2.5 hours is conducted. The study uses a double-blind, placebo-controlled crossover design to compare responses with and without the drug. During the study, participants undergo tests measuring their eyeblink startle responses and brain activity under threat conditions. Researchers use specialized tasks to assess acute and potential threat sensitivity. The total time commitment is approximately 10.5 hours. Safety is monitored throughout, and the main outcome measured is the magnitude of the eyeblink startle under threat after placebo. Brain activity and drug effects on threat responses are also evaluated to understand how Lorazepam affects these processes in different participant groups.

Processes and Circuitry Underlying Threat Sensitivity as a Treatment Target for Co-morbid Anxiety and Depression