Post-Traumatic Stress Disorder, commonly known as PTSD, is a condition that affects millions of people worldwide. Although commonly associated with military veterans, PTSD can be triggered by any traumatic event, such as sexual or physical assault, natural disasters, accidents, and sudden loss of a loved one. PTSD symptoms can vary from person to person, but they often involve severe anxiety, flashbacks, avoidance, and intrusive thoughts.
PTSD has a neurological basis, and several brain regions play a critical role in its development and maintenance. The amygdala, hippocampus, and prefrontal cortex are essential brain regions involved in PTSD. These regions interact in complex ways to form traumatic memories and regulate emotions. The amygdala, responsible for detecting threats, is hyperactive in people with PTSD, triggering a fear response even in non-threatening situations. On the other hand, the hippocampus is responsible for memory consolidation, and the prefrontal cortex is involved in decision-making and emotional regulation. In people with PTSD, these regions may be smaller or dysfunctional, leading to difficulty in regulating emotions, recalling traumatic events, and decision-making.
Another crucial aspect of PTSD is how it affects the autonomic nervous system (ANS). The ANS is responsible for regulating automatic body functions such as heart rate, breathing, and digestion. Through the polyvagal lens, a model proposed by Dr. Stephen Porges, the ANS can be classified into three hierarchical levels: the unmyelinated, dorsal vagal complex (DVC), sympathetic nervous system (SNS), and myelinated, ventral vagal complex (VVC). In people with PTSD, the DVC is often dominant, leading to a freeze response. When the DVC is overactive, people may feel disconnected, numb, or dissociated. The SNS is responsible for the fight-or-flight response, leading to heightened arousal, anxiety, and emotional reactivity. Finally, the VVC is involved in social engagement, prosocial behavior, safety, and relaxation.
Recent studies have also shown that trauma can even alter the way our DNA is expressed. Epigenetics is a field that studies how our environment can affect gene expression without changing the underlying DNA sequence. In people with PTSD, epigenetic modifications are found in genes involved in stress response, inflammation, and neuronal plasticity. These modifications can lead to long-term changes in gene expression and physiological responses to stress, making people more vulnerable to developing PTSD and other stress-related disorders.