Robert Shulman, MD: Triggers, Trauma, PTSD, and the Brain’s Fight or Flight Response

For most, the brain's limbic system activates “fight or flight” in response to intense emotions, then calms down. When triggered from trauma, those with PTSD remain in that activated state of hypervigilance. Over time those changes can affect sleep and mood disorders.

Dr. Robert Shulman is the director of the Road Home Program at Rush University Medical Center, part of the Wounded Warrior Project's Warrior Care Network.

For information about treatments for PTSD please visit The Treatment Hub.

PTSD is, can be really understood as a failure to adapt.  It’s a condition where there is a trigger, an event where the limbic system of the brain is lit up and it doesn’t sort of defervesce. And in most individuals, when there is an event, where especially one’s life is threatened or when one sees life being taken, or one is in danger, where the body normally reacts with a huge amount of adrenaline, the things that allow human beings to flee, to fight or flight. The brain goes into sort of a state of hyper-drive. Individuals who suffer PTSD unfortunately have not been able to adapt. And what happens is, over time the brain accommodates to these triggers. The brain learns to calm the circuits down such that one does not experience the flashbacks or the high anxiety, the state of panic and such. And over about a month’s time after a traumatic event, most individuals are able to accommodate the brain’s cool-off. In those who suffer post-traumatic stress disorder, the brain doesn’t cool itself off. It remains in the state of hypervigilance. This high-adrenaline state if you will, the state of awareness, of alertness, of wariness, of high vigilance such that circuits for sleep get messed up. Circuits that respond to noises, sounds, sights, visions, scents, odors, and such that might evoke memories are still on high alert. And the brain becomes continuous in the state of hyper-drive. Along with that, other circuits change. The way people feel, their emotional state, is tied to the limbic system. And that may suffer because of this. One may develop ongoing anxiety, one may develop depression. So that one event can affect more than just the person in that point in time; it can actually cause downstream changes in how the brain works, how circuits work. BrainLine is powered in part by Wounded Warrior Project to honor and empower post-9/11 injured service members, veterans, and their families.

Posted on BrainLine September 29, 2021. Reviewed September 29, 2021.

About the author: Robert B. Shulman, MD

Robert Shulman, MD is the Director of Road Home Program and currently acting chair of the Department of Psychiatry and Behavioral Sciences at Rush University Medical Center and Mental Health Service Line Director for the Rush University System for Health. He is a graduate of Lewis & Clark College and The Chicago Medical School (with many clinical rotations at the VA Hospital).

Professional headshot of Dr. Robert Shulman smiling at the camera, wearing a white doctor's coat, with a tall building in the background