Biochemical Mechanisms and Methodologies Applied to the Study of Posttraumatic Stress Disorder (PTSD)

PTSD has been considered as a syndrome with multiple faces due to the complexity of its pathophysiology. There is a need to elucidate the biochemical mechanisms involved in the disease in order to improve its diagnosis, prognosis, and treatment. Believing that the university has the responsibility to help the community, and hoping for the development of research devoted to this matter, the purpose of the present study was to present a brief review about the main biochemical mechanisms involved in PTSD and the methodologies applied to assess the disease. The review was done based on recent literature. According to the studies PTSD presents pre-exposure vulnerability factors, besides trauma-induced alterations. The disease was found associated with hypothalamic-pituitary-adrenal axis and hypothalamus-pituitarythyroid axis dysfunctions. Alterations of sympathetic nervous system activity play a role in PTSD by releasing norepinephrine and epinephrine. The release of cortisol from the adrenal cortex amplifies the SNS response, reducing it later through negative feedback mechanisms. This response leads to a decreased level of cortisol in patients with PTSD. The negative feedback contributes to neuroendocrine alterations, promoting structural brain changes that culminate in PTSD. Abnormal levels of serotonin and dopamine have been found in the disease. Mechanisms such as the induction of neuroinflammation and alterations of mitochondrial energy handling were also associated with PTSD. Controversies can be found regarding to which biomarkers would be possible for the disease. Therefore, there is a need for studies in order to find biomarkers for PTSD.