Challenging control over emotions in borderline personality disorder - a tDCS study.

BACKGROUND: Deficient cognitive control (CC) over emotional distraction is a central characteristic of borderline personality disorder (BPD). Reduced activation of the left dorsolateral prefrontal cortex (dlPFC) has been linked to this deficit. This study investigates whether it is possible to ameliorate CC deficits via anodal tDCS over the left dlPFC in BPD. Furthermore, we investigate whether the extent of CC impairment influences how well one responds to tDCS. METHODS: The effect of a single-session tDCS (1 mA for 20 min, reference electrode on the contralateral mastoid bone) to the left dlPFC (F3) on the CC of patients with BPD (N = 20) and healthy control participants (HCs, N = 20) was examined in a double-blinded, balanced randomized, sham-controlled crossover trial. A delayed response working memory task with negative, neutral and positive pictures presented during the delay period was conducted to assess CC. Stimulation was applied simultaneously with the task. RESULTS: Negative pictures caused prolonged response times as compared to a control condition in patients with BPD and HCs. Anodal tDCS to the left dlPFC did not significantly reduce this interference effect in the overall sample. Further analyses showed, however, that participants with impaired CC profited the most from anodal tDCS. In the subgroup of participants who actually showed an interference effect we found the expected significant amelioration of CC under tDCS. CONCLUSIONS: The present study demonstrates that anodal tDCS applied to the left dlPFC improves deficient CC. Thereby, base-level performance moderates tDCS effects. Hence, tDCS might be suitable to support behavioral trainings to enhance CC specifically in people whose impairments in CC are comparably high.

Heightened biological stress response during exposure to a trauma film predicts an increase in intrusive memories.

Some people develop symptoms of posttraumatic stress disorder (PTSD) after having experienced a traumatic event, whereas others do not. Intrusive memories are a cardinal symptom of PTSD and a better understanding of encoding and consolidation of intrusive memory may yield important insights on differences in the response to trauma. The primary aim of this study is to investigate whether psychosocial stress induction (Trier Social Stress Test) versus active control (placebo version) leading to respective biological stress responses during the encoding and consolidation of a film-elicited analogue trauma influences the development of intrusive memories over the course of 7 consecutive days. We hypothesized that the activation of the biological stress system increases the number of intrusive memories over the course of 7 days. This single-blind randomized placebo-controlled study examined 122 young healthy women. Biological stress response was measured by salivary cortisol, salivary α-amylase activity, and heart rate variability. Generalized linear mixed models were used to analyze longitudinal effects of activation of biological stress response on self-reported number of intrusive memories. Cross-validated regularized regression (least absolute shrinkage and selection operator) was applied for data-driven feature selection including known biological and psychological predictors. Corroborating our hypothesis, biological stress-responders to the Trier Social Stress Test reported significantly more intrusive memories after trauma film. A priori designed post hoc tests point at significantly more intrusions on Day 1 and 2 in biological stress responders. Least absolute shrinkage and selection operator regression revealed salivary cortisol, salivary α-amylase activity, heart rate variability, subjectively rated distress, fear, and (on trend level) dissociation during the trauma film as relevant predictors of intrusive memories. A heightened biological stress response in young women is associated with more intrusive memories the first days after experiencing a trauma analogue. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Lower heart rate variability at baseline is associated with more consecutive intrusive memories in an experimental distressing film paradigm.

Objectives: First evidence suggests that lower heart rate variability (HRV) is associated with more cognitive control deficits, a risk factor for the development of intrusive memories. The aim of this study was to determine whether high-frequency (HF) and low-frequency/high-frequency (LF/HF) ratio components of HRV at rest before an intrusion-inducing stressor would predict consecutive intrusive memories.Methods: Healthy female participants (n = 60) watched an established distressing film which induced intrusions. HF and LF/HF ratio were measured for 5 min prior to the stressor. The number of consecutive intrusions resulting from the distressing film was assessed throughout the following 4 days.Results: The main effect LF/HF ratio was associated with more intrusive memories, whereas, the main effect HF was associated with more intrusions on a trend level. The time × HF and time × LF/HF ratio interactions were significant, indicating a different course of number of intrusions over the 4 days depending on HF and LF/HF ratio. The regression-based parameter estimates revealed a significant association of lower HF and number of intrusions on days 1 and 2 and a significant association of higher LF/HF (i.e. lower HRV) and number of intrusions on day 1.Conclusions: The results suggest that higher baseline LF/HF ratio (i.e. lower HRV) predicts more intrusive memories in healthy women after watching a distressing film. Furthermore, the results suggest that women with lower baseline HF and higher LF/HF ratio recover at a slower rate from watching the distressing film by showing a delayed decrease in intrusive memories. Our findings support the notion that lower baseline HRV before a trauma might be a vulnerability factor for subsequent intrusive memories.

Impact of stress response systems on forced choice recognition in an experimental trauma film paradigm.

INTRODUCTION: Traumatic events are often followed by memory impairments of key features of the trauma. Stress hormones are involved in emotional memory formation. However, little is known about their influence during trauma on subsequent recognition memory. MATERIAL AND METHODS: A pooled analysis of two double-blind, placebo-controlled studies (N = 175) was performed to assess the influence of the noradrenergic system and the hypothalamus-pituitaryadrenal (HPA) axis on intrusion formation. Participants received either 10 mg yohimbine (stimulating noradrenergic activity), 0.15 mg clonidine (inhibiting noradrenergic activity), or placebo (noradrenergic manipulation study) or 20 mg hydrocortisone or placebo (hydrocortisone manipulation study), each 60 min before watching a distressing film depicting severe sexual and physical violence. After seven days, the participants performed a 24-item forced choice recognition test. Memory was assessed for pre-, peri-, and post-trauma film scenes. RESULTS: A significant film scene by intervention interaction indicated a differential influence of drug intervention on the number of correct pre-, peri-, and post-trauma film scene memories one week after the distressing film. Post hoc tests revealed that clonidine led to significantly fewer correct peri-trauma film scene memories compared to placebo and, on a trend level, to yohimbine. DISCUSSION: Pharmacological inhibition of noradrenaline during a distressing film leads to impaired emotional recognition memory for the peri-trauma film scene.