The Neurochemistry and Epigenetics of PTSD

This chapter reviews the neurochemistry and epigenetics of posttraumatic stress disorder (PTSD). Traditional views of the neurochemistry of PTSD focus on alterations in classical central nervous system neurotransmitters serotonin and norepinephrine and pathological reactivity in the hypothalamic-pituitary-adrenal axis, and these are only briefly noted here. Instead, the chapter emphasizes a series of new conceptualizations and neurochemical data that have recently been elucidated. One is the recognition of the symptoms and neurobiology of PTSD as a moving target, being very different in different stages of illness evolution. Differences are apparent in the neurochemistry involved in early life stressor-related vulnerabilities to PTSD, the acute stress reaction, compensation and resolution phases, or ongoing chronicity with sleep disturbance, nightmares, flashbacks, hyperarousal, and dulling and depression. The neurochemical abnormalities vary as a function of this temporal unfolding and the common acquisition and progression of comorbid syndromes of alcohol and substance abuse.