Cognitive load and autonomic response patterns under negative priming demand in depersonalization-derealization disorder.

Previous studies have yielded evidence for cognitive processing abnormalities and alterations of autonomic functioning in depersonalization-derealization disorder (DPRD). However, multimodal neuroimaging and psychophysiology studies have not yet been conducted to test for functional and effective connectivity under cognitive stress in patients with DPRD. DPRD and non-referred control subjects underwent a combined Stroop/negative priming task, and the neural correlates of Stroop interference effect, negative priming effect, error rates, cognitive load span and average amplitude of skin conductance responses were ascertained for both groups. Evoked haemodynamic responses for basic Stroop/negative priming activations were compared. For basic Stroop to neutral contrast, patients with DPRD differed in the location (inferior vs. superior lobule) of the parietal region involved, but showed similar activations in the left frontal region. In addition, patients with DPRD also co-activated the dorsomedial prefrontal cortex (BA9) and posterior cingulate cortex (BA31), which were also found to be the main between-group difference regions. These regions furthermore showed connectivity with frequency of depersonalization states. Evoked haemodynamic responses drawn from regions of interest indicated significant between-group differences in 30-40% of time points. Brain-behaviour correlations differed mainly in laterality, yet only slightly in regions. A reversal of autonomic patterning became evident in patients with DPRD for cognitive load spans, indicating less effective arousal suppression under cognitive stress - patients with DPRD showed positive associations of cognitive load with autonomic responses, whereas controls exhibit respective inverse association. Overall, the results of the present study show only minor executive cognitive peculiarities, but further support the notion of abnormalities in autonomic functioning in patients with DPRD.

Abnormal cardiovascular sympathetic and parasympathetic responses to physical and emotional stimuli in depersonalization disorder.

BACKGROUND: Depersonalization disorder (DPD) is characterized by a subjective sense of unreality, disembodiment, emotional numbing and reduced psychogenic (sudomotor) sympathoexcitation. AIMS: Three related experiments utilized escalating physical and emotional challenges in 14 DPD participants and 16 controls aimed to elucidate (i) whether the cardiovascular sympathetic (SNS) and parasympathetic (PNS) nervous systems are implicated in DPD pathophysiology and (ii) if possible, to determine whether the blunted sympathoexcitation in DPD is peripherally or centrally mediated. METHOD: Participants completed the Beck Anxiety Inventory (BAI), Dissociative Experience Scale (DES), and Cambridge Depersonalization Scale (CDS). Study I recorded heart rate (HR) and blood pressure (BP) during 5 min supine baseline, 3 min sustained handgrip (HG), 3 min cold pressor (CP) and 5 min 60° head-up tilt (HUT). In study II, HR, BP, and heart rate variability (HRV) were recorded during 5 min simultaneous 60° HUT and continuous presentation of unpleasant images (5 s per image). Study III examined HR and BP orienting responses (ORs) to simultaneous 60° HUT and pseudorandom presentation of unpleasant, neutral and pleasant images (5 s per image 3 min 25 s). OR data was grouped by image valence post hoc. RESULTS: DPD BAI (p = 0.0004), DES (p = 0.0002), and CDS (p ≤ 0.0001) scores were higher than controls. The DPD group produced diminished diastolic BP (DBP) (p = 0.045) increases to HG. Other indices were comparable between groups. DPD participants produced diminished systolic BP (SBP) (p = 0.003) and DBP (p = 0.002) increases, but greater (p = 0.004) HR increases to CP. In study II, DPD high frequency HRV (HF-HRV)-indicating parasympathetic vagal activity-was reduced (p = 0.029). In study III, DPD DBP was higher throughout the 5 s duration of HUT/pseudorandom unpleasant image presentation (1 s, p = 0.002, 2 s p = 0.033, 3 s p = 0.001, 4 s p = 0.009, 5 s p = 0.029). CONCLUSIONS: Study I's BP pressor data supports previous findings of suppressed sympathoexcitation in DPD. The greater HR increases to CP, decreased HF-HRV in study II, and increased DBP during unpleasant ORs in study III implicates the SNS and PNS in DPD pathophysiology. These studies suggest the cardiovascular autonomic dysregulation in DPD is likely to be centrally-mediated.

La despersonalización: aspectos clínicos y neurobiológicos / Despersonalization: Clinical and Neurobiological Aspects

Introducción: A pesar de haberse descrito hace más de un siglo, la despersonalización continúa siendo un fenómeno poco comprendido y pobremente conceptualizado. Objetivo: Proporcionar una visión actualizada del fenómeno a la luz de la psicopatología descriptiva y desarrollos empíricos recientes en neurobiología y comparación transcultural. Método: Se realizó una revisión selectiva con énfasis en la literatura reciente de la despersonalización. Desarrollo y conclusión: La literatura reciente está representada por tres vertientes investigativas, de las cuales se pueden extraer las siguientes conclusiones: (a) El fenómeno de despersonalización tiene una estructura compleja caracterizada por varias dimensiones independientes. En este sentido parece constituir más un síndrome que un síntoma. (b) Estudios neurobiológicos recientes sugieren la existencia de una desconexión funcional entre la percepción y sus concomitantes afectivos, lo cual hace que la experiencia conciente parezca desprovista de “colorido emocional”. (c) La prevalencia de la despersonalización parece sensible a variables sociológicas y culturales, de tal modo que culturas caracterizadas por alto individualismo parecen conferir vulnerabilidad al fenómeno...

Introduction: Although described more than a century ago, depersonalization continues to be a poorly understood and poorly conceptualized phenomenon. Objective: To supply a current vision of depersonalization in the light of descriptive psychopathology and recent empirical developments in neurobiology and transcultural comparisons. Method: Selective review of literature on depersonalization with emphasis on recent literature. Development and conclusion: Research found in recent literature moves along three tracks, from which these conclusions can be extracted: (a) The phenomenon of depersonalization has a complex structure characterized by several independent dimensions. In this sense it seems to constitute more of a syndrome than a symptom. (b) Recent neurobiological studies suggest the existence of a functional disconnection between perception and its affective concomitants which renders the conscious experience as devoid of “emotional coloring”. (c) The prevalence of depersonalization seems to be sensitive to sociological and cultural variables so that cultures with high individualism seem to confer vulnerability to the phenomenon...

Depersonalization and individualism: the effect of culture on symptom profiles in panic disorder.

It has been proposed that highly individualistic cultures confer vulnerability to depersonalization. To test this idea, we carried out a comprehensive systematic review of published empirical studies on panic disorder, which reported the frequency of depersonalization/derealization during panic attacks. It was predicted that the frequency of depersonalization would be higher in Western cultures and that a significant correlation would be found between the frequency of depersonalization and individualism scores of the participant countries. As predicted, the frequency of depersonalization during panic was significantly lower in nonwestern countries. There was also a significant correlation between frequency of depersonalization and Individualism (rho = 0.68, p < 0.0001), and between fears of losing control (rho = 0.57, p = 0.005) and individualism. These findings are interpreted in light of recent studies suggesting that individualistic cultures are characterized by hypersensitivity to threat and by an external locus of control. Two features may be relevant in the genesis of depersonalization.

Empathy and enduring depersonalization: the role of self-related processes.

Empathy has two key components: affective and cognitive. It relies on "embodied" processes such as the generation, representation and perception of feeling states. People diagnosed with Depersonalization Disorder (DPD) report disturbances in affective experience, such as emotional numbing, alongside aberrations in "body image" such as increased self-focus and feelings of "disembodiment". DPD therefore provides a test bed for the role of such self-related processes in empathy. We tested 16 participants diagnosed with DPD and 48 control volunteers on measures of cognitive and affective empathy. We used self-report measures (EQ; Baron-Cohen & Wheelwright, 2004), an objective measure of cognitive empathy-the "Eyes" task (Baron-Cohen, Wheelwright, Hill, Raste, & Plumb, 2001), and a novel task tapping affective empathy, utilizing speech rate as an implicit measure of physiological arousal. We also measured participants' tendency to use mental representations that relate to the self during the affective empathy task. The DPD group showed intact performance on the cognitive empathy task. However, there was a disruption in the physiological component of affective empathy alongside a more pronounced reliance on mental representations of the self. These findings suggest affective empathy to be reliant on intact emotional experience in the observer. In addition, excessive self-focus may be detrimental to an empathic response.