Faculty Bibliography

In this article, the authors present evidence regarding a dissociative subtype of PTSD, with clinical and neurobiological features that can be distinguished from nondissociative PTSD. The dissociative subtype is characterized by overmodulation of affect, while the more common undermodulated type involves the predominance of reexperiencing and hyperarousal symptoms. This article focuses on the neural manifestations of the dissociative subtype in PTSD and compares it to those underlying the reexperiencing/hyperaroused subtype. A model that includes these two types of emotion dysregulation in PTSD is described. In this model, reexperiencing/hyperarousal reactivity is viewed as a form of emotion dysregulation that involves emotional undermodulation, mediated by failure of prefrontal inhibition of limbic regions. In contrast, the dissociative subtype of PTSD is described as a form of emotion dysregulation that involves emotional overmodulation mediated by midline prefrontal inhibition of the same limbic regions. Both types of modulation are involved in a dynamic interplay and lead to alternating symptom profiles in PTSD. These findings have important implications for treatment of PTSD, including the need to assess patients with PTSD for dissociative symptoms and to incorporate the treatment of dissociative symptoms into stage-oriented trauma treatment.

BACKGROUND: In an attempt to avoid unknown influence, most neuroimaging studies examining the pathophysiology of posttraumatic stress disorder (PTSD) exclude patients taking medications. Here we review the empirical evidence for relevant medications having a confounding effect on task performance or cerebral blood flow (CBF) in this population. The evidence for potentially confounding effects of psychotherapy in PTSD are also discussed. METHODS: The literature that we reviewed was obtained through a PubMed search from 1980 to 2009 using the search terms posttraumatic stress disorder, PTSD, psychotropic medications, neuroimaging, functional magnetic resonance imaging, positron emission tomography, cerebral blood flow, CBF, serotonin-specific reuptake blocker, benzodiazepine, ketamine, methamphetamine, lamotrigine and atypical antipsychotic agents. RESULTS: The empirical evidence for relevant medications having a confounding effect on task performance or CBF in relevant areas remains sparse for most psychotropic medications among patients with PTSD. However, considerable evidence is accumulating for 2 of the most commonly prescribed medication classes (serotonin-specific reuptake inhibitors and benzodiazepines) in healthy controls. Compelling data for the potentially confounding effects on brain areas relevant to PTSD for psychotherapeutic interventions are also accumulating. CONCLUSION: Neuroimaging studies examining the pathophysiology of PTSD should ideally recruit both medicated (assuming that the medication treatment has not resulted in the remission of symptoms) and unmedicated participants, to allow the findings to be generalized with greater confidence to the entire population of patients with PTSD. More research is needed into the independent effects of medications on task performance and CBF in regions of interest in PTSD. Neuroimaging studies should also take into account whether patients are currently engaged in psychotherapeutic treatment.

The newly proposed criteria for posttraumatic stress disorder (PTSD) in the Diagnostic and Statistical Manual (DSM-V) include dysregulation of a variety of emotional states including fear, anger, guilt, and shame, in addition to dissociation and numbing. Consistent with these revisions, we postulate two models of emotion dysregulation in PTSD in which fear is not the prevailing emotion but is only one of several components implicated in a dysregulated emotional system that also mediates problems regulating anger, guilt, shame, dissociation, and numbing.We discuss whether there is a relationship between fear and other emotion regulation systems that may help further our understanding of PTSD and its underlying neurocircuitry. Two pathways describing the relationship between fear and other emotion regulation systems in PTSD are proposed. The first pathway describes emotion dysregulation as an outcome of fear conditioning through stress sensitization and kindling. The second pathway views emotion dysregulation as a distal vulnerability factor and hypothesizes a further exacerbation of fear and other emotion regulatory problems, including the development of PTSD after exposure to one or several traumatic event(s) later in life. Future research and treatment implications are discussed.

The paper discusses the design and evaluation of a multimedia software application, which can be used in the treatment of combat-related posttraumatic stress disorder (PTSD). The application allows patients and therapist to visualize the patients' past experience using maps, personal photos, stories and self-created 3D virtual worlds. The tool aims to allow patients to restructure and relearn about their past experience involving the problematic stressors. Findings of a first experiment with non-patients (N=18) suggests that the tool can facilitate more detailed storytelling. Participants stated that using the application was appealing and enjoyable. Insights were also acquired with a case study of a veteran suffering from combat-related PTSD. This case study showed how a patient uses and interacts with the system in a therapeutic setting.