Functional Magnetic Resonance Imaging (fMRI) of PTSD. Current Status and Future Directions
EREL SHVIL, KATHARINE REINER VAN DER HOORN, SANTIAGO PAPINI, GREGORY M. SULLIVAN, AND YUVAL NERIA
Although trauma is an integral facet of the human existence, individuals suffering from post-traumatic stress disorder (PTSD) often exhibit debilitating pathological responses long after exposure. Although PTSD was originally conceptualized as a solely psychological disorder, research has uncovered several neurobiological markers of the syndrome that are associated with symptom severity and responses to stimuli. This chapter reviews research from the past decade of functional magnetic resonance imaging (fMRI) research on PTSD (2004-14). We focused on biomarkers of fear processing, with paradigms including Pavlovian conditioning and extinction, fearful faces, and traumatic imagery; emotional regulation and emotional memory; and attention bias; as well as treatment outcomes. Key findings include hyperactivation of the dorsal anterior cingulate cortex (dACC) and hypoactivation of the ventromedial prefrontal cortex (vmPFC) in fear processing, heightened activity in the amygdala and insula during emotion regulation, hippocampal alterations in memory processes, and functional variations within the amygdala, insula, hippocampus, and medial PFC (mPFC) during and after various psychotherapeutic and pharmacological treatments. There have been few long-term outcome studies of PTSD. Moreover, future long-term outcome studies, whether naturalistic or follow-ups of patients in clinical trials, need to incorporate neurobiological measures along with the batteries of self-reports that are traditionally collected.