To better understand what is happening to the brain during Post Traumatic Stress, let’s take the following examples. You are walking peacefully in the forest when a bear appears in front of you. Another situation could be where you witness a terrible crime. At this point, the amygdala, which is a region in the center of the brain, will sound the alarm. It will activate and send signals to other areas of the brain to trigger a series of biological mechanisms to prepare you to face the threat. Adrenaline production will be launched, heart and respiratory rates will accelerate, pupils will expand and many more mechanisms will be activated. It is then that the body will put itself in a state of emergency and hypervigilance.

Once the threat is removed, the amygdala should “return to rest” and thus remove the state of emergency in the nervous system. But when the event is too emotional or too long, the amygdala will not return completely to its original state. The emergency button will always remain a little depressed. It is then that people will feel an anxiety and / or hypervigilence that is omnipresent.