[Neural mechanisms of dissociation: implication for borderline personality disorder]. / Neurale mechanismen van dissociatie: implicaties voor borderline­persoonlijkheidsstoornis.

BACKGROUND: Dissociation is a prevalent symptom in borderline personality disorder (BPD), which can have detrimental effects on everyday functioning and treatment. Until now, little is known about the brain networks implicated in dissociation in BPD. Research on dissociative disorders and posttraumatic stress disorder found alterations in networks implicated in cognitive control and arousal modulation. However, it is unknown whether these alterations are also affected in BPD.
AIM: To provide an overview of the definitions, neurobiological models, and neuroimaging research on dissociation in BPD.
METHOD: Review of the literature.
RESULTS: During dissociation in BPD, there is evidence for an altered recruitment and interplay of brain regions implicated in the regulation of stress responses and emotions, attention, memory, and self-referential processing (amygdala, anterior cingulate cortex, inferior frontal gyrus, medial prefrontal cortex, superior temporal gyrus, and inferior parietal lobule).
CONCLUSION: Dissociation is associated with alterations in brain networks that regulate affect-cognitive processing in BPD. Given the substantial impact of dissociation on treatment and neural processing, dissociative symptoms should be taken into account in future research and treatment of BPD, even if they are not the primary focus.

Delay discounting and response disinhibition under acute experimental stress in women with borderline personality disorder and adult attention deficit hyperactivity disorder.

BACKGROUND: Impulsivity is a core feature of borderline personality disorder (BPD) and attention deficit hyperactivity disorder (ADHD). In BPD, impulsive behavior primarily occurs under acute stress; impulse control deficits under non-stress conditions may be partly related to co-morbid ADHD. We aimed to investigate whether acute experimental stress has an impact on self-reported impulsivity, response inhibition (action withholding, action cancelation) and delay discounting in BPD compared to ADHD. METHOD: Thirty female BPD patients, 28 female ADHD patients (excluding patients with co-morbid BPD and ADHD), and 30 female healthy controls (HC) completed self-reports and behavioral measures of impulsivity (IMT, assessing action withholding; GoStop, measuring action cancelation, Delay Discounting Task) under baseline conditions and after an experimental stress induction (Mannheim Multicomponent Stress Test). RESULTS: Both patient groups reported higher impulsivity than HC, ADHD reported higher trait impulsivity than BPD. On the IMT, ADHD showed significant action-withholding deficits under both conditions, while BPD performed significantly worse than HC under stress. In BPD but not ADHD and HC, action-withholding deficits (IMT) were significantly increased under stress compared to baseline, while no group/stress effects were found for action cancelation (GoStop). Delay discounting was significantly more pronounced in BPD than in HC (no stress effect was found). CONCLUSIONS: In BPD, behavioral deficits in action withholding (but not in action cancelation) appear to be influenced by acute experimental stress. Delay discounting seems to be a general feature of BPD, independent of co-morbid ADHD and acute stress, possibly underlying typical expressions of behavioral impulsivity in the disorder.

Impact of stress on different components of impulsivity in borderline personality disorder.

BACKGROUND: Previous research on impulsivity in borderline personality disorder (BPD) has revealed inconsistent findings. Impulsive behaviour is often observed during states of emotional distress and might be exaggerated by current attention deficit hyperactivity disorder (ADHD) symptoms in individuals with BPD. We aimed to investigate different components of impulsivity dependent on stress induction controlling for self-reported ADHD symptoms in BPD. METHOD. A total of 31 unmedicated women with BPD and 30 healthy women (healthy controls; HCs), matched for age, education and intelligence, completed self-reports and behavioural tasks measuring response inhibition (go/stop task) and feedback-driven decision making (Iowa Gambling Task) under resting conditions and after experimental stress induction. ADHD symptoms were included as a covariate in the analyses of behavioural impulsivity. Additionally, self-reported emotion-regulation capacities were assessed. RESULTS: BPD patients reported higher impulsive traits than HCs. During stress conditions - compared with resting conditions - self-reported impulsivity was elevated in both groups. Patients with BPD reported higher state impulsivity under both conditions and a significantly stronger stress-dependent increase in state impulsivity. On the behavioural level, BPD patients showed significantly impaired performance on the go/stop task under stress conditions, even when considering ADHD symptoms as a covariate, but not under resting conditions. No group differences on the Iowa Gambling Task were observed. Correlations between impulsivity measures and emotion-regulation capacities were observed in BPD patients. CONCLUSIONS: Findings suggest a significant impact of stress on self-perceived state impulsivity and on response disinhibition (even when considering current ADHD symptoms) in females with BPD.

Amygdala and anterior cingulate resting-state functional connectivity in borderline personality disorder patients with a history of interpersonal trauma.

BACKGROUND: Studies in borderline personality disorder (BPD) have consistently revealed abnormalities in fronto-limbic brain regions during emotional, somatosensory and cognitive challenges. Here we investigated changes in resting-state functional connectivity (RSFC) of three fronto-limbic core regions of specific importance to BPD. METHOD: Functional magnetic resonance imaging data were acquired in 20 unmedicated female BPD patients and 17 healthy controls (HC, matched for age, sex and education) during rest. The amygdala, and the dorsal and ventral anterior cingulate cortex (ACC) were defined as seeds to investigate RSFC patterns of a medial temporal lobe network, the salience network and default mode network. The Dissociation Experience Scale (DES), a measure of trait dissociation, was additionally used as a predictor of RSFC with these seed regions. RESULTS: Compared with HC, BPD patients showed a trend towards increased RSFC between the amygdala and the insula, orbitofrontal cortex and putamen. Compared with controls, patients furthermore exhibited diminished negative RSFC between the dorsal ACC and posterior cingulate cortex, a core region of the default mode network, and regions of the dorsomedial prefrontal cortex. Last, increased negative RSFC between the ventral ACC and medial occipital regions was observed in BPD patients. DES scores were correlated with amygdala connectivity with the dorsolateral prefrontal cortex and fusiform gyrus. CONCLUSIONS: Our findings suggest alterations in resting-state networks associated with processing of negative emotions, encoding of salient events, and self-referential processing in individuals with BPD compared with HC. These results shed more light on the role of abnormal brain connectivity in BPD.

Predictors of complex PTSD: the role of trauma characteristics, dissociation, and comorbid psychopathology.

BACKGROUND: Complex Posttraumatic Stress Disorder (CPTSD) has previously been associated with earlier trauma onset, repeated interpersonal traumatization, more dissociation, and more comorbid psychopathology. However, it is still debated if the afore-mentioned risk factors are related to CPTSD diagnosis or rather indicative of a more severe form of post-traumatic distress. The aim of this study was to compare patients with a CPTSD diagnosis to those with PTSD in trauma characteristics (onset, chronicity, interpersonal nature, familiarity with perpetrator), dissociation, and psychiatric comorbidities, while accounting for symptom severity. METHODS: In total, N = 81 patients with a trauma history (n = 43 with CPTSD; n = 37 with PTSD) underwent diagnostic interviews by trained clinicians and completed measures on CPTSD symptom severity, trauma characteristics, and dissociation (Screening for Complex PTSD; Dissociative Experience Scale Taxon). RESULTS: Patients with CPTSD reported earlier onset of trauma, more trauma perpetrated by acquaintances or family members, and more comorbidities than those with PTSD, also when accounting for symptom severity. No group differences in chronicity and dissociation were found. Severity of CPTSD was associated with earlier onset, familiarity with perpetrator, more comorbid (affective) disorders, and dissociation in both diagnostic groups. CONCLUSION: Findings largely confirm earlier research, suggesting that CPTSD is associated with traumatic events that start earlier in life and are perpetrated by acquaintances. Focusing on transdiagnostic symptoms, such as dissociation, may help to detain symptom deterioration. Due to the small sample size, findings need to be interpreted with caution and further research is needed to replicate findings in larger samples. Future research should also elucidate possible working mechanisms besides dissociation, such as emotion dysregulation or negative self-image.

Influence of emotional distraction on working memory performance in borderline personality disorder.

BACKGROUND: Emotion dysregulation, characterized by heightened emotional arousal and increased emotional sensitivity, is a core feature of borderline personality disorder (BPD). Although current theories emphasize the disruptive potential of negative emotions on cognitive functioning in BPD, behavioral and neurobiological data on this relationship are still lacking. METHOD: Using functional magnetic resonance imaging (fMRI), neural activity was investigated in 22 unmedicated BPD patients and 22 healthy participants (matched for age, education and intelligence) performing an adapted Sternberg working memory task, while being distracted by emotional (negatively arousing) and neutral pictures from the International Affective Picture System (IAPS). RESULTS: Emotional distraction was associated with significantly higher activation in the amygdala and decreased activation in the dorsolateral prefrontal cortex (DLPFC), extending findings of previous studies in healthy individuals. Patients with BPD showed significantly longer reaction times (RTs) along with significantly higher activation in the amygdala and insula during emotional distraction compared to healthy participants, suggesting that they were more distracted by emotional pictures during the working memory task. Moreover, in the group of BPD patients, a significant negative correlation was found between activation in limbic brain regions and self-reports of current dissociative states. CONCLUSIONS: Our findings suggest hyper-responsiveness to emotionally distracting pictures in BPD patients that negatively affects working memory performance. This stresses the importance of emotion dysregulation in the context of cognitive functioning. Moreover, our findings suggest that dissociative states have a dampening effect on neural reactivity during emotional challenge in BPD.