Faculty Bibliography

BACKGROUND: We present recommendations for revision of the diagnostic criteria for the Dissociative Disorders (DDs) for DSM-5. The periodic revision of the DSM provides an opportunity to revisit the assumptions underlying specific diagnoses and the empirical support, or lack of it, for the defining diagnostic criteria. METHODS: This paper reviews clinical, phenomenological, epidemiological, cultural, and neurobiological data related to the DDs in order to generate an up-to-date, evidence-based set of DD diagnoses and diagnostic criteria for DSM-5. First, we review the definitions of dissociation and the differences between the definitions of dissociation and conceptualization of DDs in the DSM-IV-TR and the ICD-10, respectively. Also, we review more general conceptual issues in defining dissociation and dissociative disorders. Based on this review, we propose a revised definition of dissociation for DSM-5 and discuss the implications of this definition for understanding dissociative symptoms and disorders. RESULTS: We make the following recommendations for DSM-5: 1. Depersonalization Disorder (DPD) should derealization symptoms as well. 2. Dissociative Fugue should become a subtype of Dissociative Amnesia (DA). 3. The diagnostic criteria for DID should be changed to emphasize the disruptive nature of the dissociation and amnesia for everyday as well as traumatic events. The experience of possession should be included in the definition of identity disruption. 4. Should Dissociative Trance Disorder should be included in the Unspecified Dissociative Disorder (UDD) category. CONCLUSIONS: There is a growing body of evidence linking the dissociative disorders to a trauma history, and to specific neural mechanisms.

BACKGROUND: The Type D (distressed) personality refers to a general propensity to psychological distress defined by the combination of negative affectivity and social inhibition. Type D personality predicts poor mental and physical health in cardiac patients, but it has been argued that its assessment is affected by the state of illness. Therefore, validation of the Type D construct in healthy adults remains essential. PURPOSE: The objectives of this study were (1) to validate Type D personality against temperament and character dimensions in young, healthy adults and (2) to investigate the association between Type D personality and pre-deployment mental health. METHOD: Type D personality, temperament, and questionnaires on mental health were filled out by 86 healthy male Dutch military personnel before UN deployment to Afghanistan. RESULTS: Type D personality was present in 16% of healthy military personnel before deployment. The Type D components social inhibition (alpha = 0.89) and negative affectivity (alpha = 0.85) correlated positively with harm avoidant temperament (r = 0.66 and 0.46) and negatively with self-directed character (r = -0.33 and -0.57). In addition, these four traits loaded on the same broad personality dimension. Military men with a Type D personality not only reported significantly less self-directedness and more harm avoidance as compared to non-Type D men (p < 0.001) but also more symptoms of PTSD, general emotional distress, and hostility (all p < 0.012). CONCLUSIONS: Type D personality was associated with harm avoidance, low self-directedness, and increased symptoms of PTSD and hostility in men awaiting deployment. This association was not caused by any somatic confounding in these young, healthy men.

Few prospective studies on pre-trauma predictors for subsequent development of posttraumatic stress disorder (PTSD) have been conducted. In this study we prospectively investigated whether pre-deployment personality and the cortisol awakening response (CAR) predicted development of PTSD symptoms in response to military deployment. Furthermore, we hypothesized that potential effects of age, childhood trauma and previous deployment on development of PTSD symptoms were mediated via pre-deployment personality, CAR and PTSD symptoms. Path analysis was performed on data from 470 male soldiers collected before and six months after a 4-month deployment to Afghanistan. Before deployment, personality was assessed with the short-form Temperament-Character Inventory and the Cook-Medley Hostility scale. In addition, pre-deployment saliva sampling for assessment of the CAR was performed immediately after awakening and 15, 30 and 60min thereafter. Pre-deployment high hostility and low self-directedness represented intrinsic vulnerabilities for development of PTSD symptoms after deployment. The CAR assessed before deployment did not predict PTSD symptoms after deployment. Pre-deployment low-to-moderate PTSD symptoms were associated with PTSD symptoms after deployment. As hypothesized, the effects of age and childhood trauma on PTSD symptoms after deployment were mediated via personality and pre-deployment PTSD symptoms. However, the number of previous deployments was not related to development of PTSD symptoms. The total model explained 24% of variance in PTSD symptoms after military deployment.

Exposure to severe stressors increases the risk for psychiatric disorders in vulnerable individuals, but can lead to positive outcomes for others. However, it remains unknown how severe stress affects neural functioning in humans and what factors mediate individual differences in the neural sequelae of stress. The amygdala is a key brain region involved in threat detection and fear regulation, and previous animal studies have suggested that stress sensitizes amygdala responsivity and reduces its regulation by the prefrontal cortex. In this study, we used a prospective design to investigate the consequences of severe stress in soldiers before and after deployment to a combat zone. We found that combat stress increased amygdala and insula reactivity to biologically salient stimuli across the group of combat-exposed individuals. In contrast, its influence on amygdala coupling with the insula and dorsal anterior cingulate cortex was dependent on perceived threat, rather than actual exposure, suggesting that threat appraisal affects interoceptive awareness and amygdala regulation. Our results demonstrate that combat stress has sustained consequences on neural responsivity, and suggest a key role for the appraisal of threat on an amygdala-centered neural network in the aftermath of severe stress.

Psychological trauma and prolonged stress may cause mental disorders such as posttraumatic stress disorder (PTSD). Pretrauma personality is an important determinant of posttraumatic adjustment. Specifically, trait neuroticism has been identified as a risk factor for PTSD. Additionally, the combination of high negative affectivity or neuroticism with marked social inhibition or introversion, also called Type D personality (Denollet, 2000), may compose a risk factor for PTSD. There is no research available that examined pretrauma Type D personality in relation to PTSD. The present study examined the predictive validity of the Type D personality construct in a sample of Dutch soldiers. Data were collected prior to and 6 months after military deployment to Afghanistan. Separate multiple regression analyses were performed to examine the predictive validity of Type D personality. First, Type D personality was defined as the interaction between negative affect and social inhibition (Na x Si). In a second analysis, Type D was defined following cutoff criteria recommended by Denollet (2000). Results showed that negative affectivity was a significant predictor of PTSD symptoms. Social inhibition and the interaction Na x Si did not add to the amount of explained variance in postdeployment PTSD scores over the effects of childhood abuse, negative affectivity, and prior psychological symptoms. A second analysis showed that Type D personality (dichotomous) did not add to the amount of explained variance in postdeployment PTSD scores over the effects of childhood abuse, and prior psychological symptoms. Therefore, Type D personality appears to be of limited value to explain development of combat-related PTSD symptoms.

OBJECTIVE: The development of posttraumatic stress disorder (PTSD) is influenced by preexisting vulnerability factors. The authors aimed at identifying a preexisting biomarker representing a vulnerability factor for the development of PTSD. To that end, they determined whether the dexamethasone binding capacity of leukocytes, as a measure of glucocorticoid receptor (GR) number, before exposure to trauma was a predictor of development of PTSD symptoms. In addition, the authors analyzed mRNA expression for GR subtypes and GR target genes. METHOD: Participants were selected from a large prospective study on deployment-related disorders, in which peripheral blood mononuclear cells (PBMCs) were obtained prior to and 1 and 6 months after military deployment. Participants included armed forces personnel with high levels of PTSD symptoms 6 months after deployment (N=34) and comparison subjects without high levels of PTSD or depressive symptoms (N=34) matched for age, rank, previous deployments, educational level, and function during deployment. RESULTS: Before military deployment, the GR number in PBMCs was significantly higher in participants who developed high levels of PTSD symptoms after deployment relative to matched comparison subjects. Logistic regression analysis showed that the risk for inclusion in the PTSD group after deployment increased 7.5-fold with each GR increase of 1,000. No group differences were observed in mRNA expression of GR-alpha, GR-P, GR-beta, glucocorticoid-induced leucine zipper (GILZ), serum and glucocorticoid-inducible kinase-1 (SGK-1), and FKBP5. The higher GR number in the PTSD group was maintained at 1 and 6 months after deployment. CONCLUSIONS: These results demonstrate that a preexisting high GR number in PBMCs is a vulnerability factor for subsequent development of PTSD symptoms.