Neuroimaging research in posttraumatic stress disorder – Focus on amygdala, hippocampus and prefrontal cortex

Neuroimaging research reflects the complexity of post-traumatic stress disorder and shares some common difficulties of post-traumatic stress disorder research, such as the different classifications of the disorder over time, changes in diagnostic criteria, and extensive comorbidities, as well as precisely delineated and prevailing genetic and environmental determinants in the development of the disorder and its clinical manifestations. Synthesis of neuroimaging findings in an effort to clarify causes, clinical manifestations, and consequences of the disorder is complicated by a variety of applied technical approaches in different brain regions, differences in symptom dimensions in a study population, and typically small sample sizes, with the interplay of all of these consequently bringing about divergent results. Furthermore, combinations of the aforementioned issues serve to weaken any comprehensive meta-analytic approach. In this review, we focus on recent neuroimaging studies and those performed on larger samples, with particular emphasis on research concerning the amygdala, hippocampus, and prefrontal cortex, as these are the brain regions postulated by the core research to play a prominent role in the pathophysiology of post-traumatic stress disorder. Additionally, we review the guidelines for future research and list a number of new intersectional and cross-sectional approaches in the area of neuroimaging. We conclude that future neuroimaging research in post-traumatic stress disorder will certainly benefit from a higher integration with genetic research, better profiling of control groups, and a greater involvement of the neuroimaging genetics approach and from larger collaborative studies.