Complex PTSD is a relatively new addition to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Researchers are still trying to pin down the specific causes of CPTSD. We do know that trauma can have a significant impact on the brain.
Animal studies show that it affects the hippocampus, amygdala, and prefrontal cortex. It can also affect neurochemical levels, particularly norepinephrine and cortisol.
These regions are critical for memory function and our stress response. The two affected neurochemicals also play a significant role in stress response. The result is long-term emotional dysfunction and heightened levels of stress.
CPTSD is most common in people who have gone through abuse at the hands of their caregiver. This person might have been a parent, close family member, or an authority figure. But other long-term traumatic experiences also contribute to CPTSD, including: