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 include 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. 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: Healthy sleep facilitates the consolidation of newly acquired memories. Although patients with posttraumatic stress disorder (PTSD) often complain of sleep disturbances and memory deficits, the interrelatedness of these symptoms is not well understood. Sleep may be disturbed in PTSD by increased awakenings during sleep, which has been associated with decreased growth hormone (GH) secretion. We conducted a controlled study in which we assessed sleep fragmentation, nocturnal secretion of GH, and memory consolidation in patients with PTSD. METHODS: While sleep EEG was being monitored, 13 veterans with PTSD, 15 trauma controls (TC) and 15 healthy controls (HC) slept with an iv catheter, through which blood was collected every 20 min from 23:00 h to 08:00 h. Declarative memory encoding was assessed with the 15 word task before sleep, and consolidation was assessed the next morning by a free recall. RESULTS: Sleep was more fragmented in patients with PTSD, with more awakenings in the first half of the night (p<0.05). Plasma levels of GH during the night were significantly decreased in PTSD compared with HC (p<0.05). Furthermore, GH secretion and awakenings were independent predictors for delayed recall, which was lower in PTSD compared to HC (p<0.05). CONCLUSIONS: These data show that PTSD is associated with increased awakenings during sleep and decreased nocturnal GH secretion. Furthermore, decreased GH secretion may be related to sleep fragmentation and both variables may exert a negative effect on sleep dependent memory consolidation.

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.

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.

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.