Evidence of deviant parasympathetic response to social exclusion in women with borderline personality disorder

Stressful social situations like social exclusion are particularly challenging for patients with borderline personality disorder (BPD) and often lead to dysfunctional reactive behaviour of aggression and withdrawal. The autonomous signature of these core symptoms of BPD remains poorly understood. The present study investigated the parasympathetic response to social exclusion in women with BPD (n = 62) and healthy controls (HC; n = 87). In a between-subjects design, participants experienced objective social exclusion or overinclusion in the Cyberball task, a virtual ball-tossing game. Need threat scores served as individual measures of perceived exclusion and the resulting frustration of cognitive-emotional needs. Five-minute measurements of high-frequency heart rate variability (HF-HRV) at three time points (before, during, after Cyberball) indicated parasympathetic tone and regulation. We observed a trend towards lowered baseline HF-HRV in BPD vs. HC in line with previous findings. Interestingly, the parasympathetic response of patients with BPD to objective and perceived social exclusion fundamentally differed from HC: higher exclusion was associated with increased parasympathetic activation in HC, while this autonomic response was reversed and blunted in BPD. Our findings suggest that during social stress, the parasympathetic nervous system fails to display an adaptive regulation in patients with BPD, but not HC. Understanding the autonomous signature of the stress response in BPD allows the formulation of clinically relevant and biologically plausible interventions to counteract parasympathetic dysregulation in this clinical group.

Causes, clinical characteristics, and outcomes of high lithium levels and intoxications: Retrospective analysis of patient records

BACKGROUND

The mood stabilizer lithium has a narrow therapeutic index with a relevant risk of intoxication. We used real-world hospital data to identify causes, treatment courses, and outcomes of high lithium levels and intoxications.

METHODS

Retrospective chart review of patients with a lithium concentration of ⩾1.1 mmol/L, who were treated at Charité University Medical Center Berlin.

RESULTS

We identified 136 patients (58% women; mean age: 54.7 years) with high lithium levels or intoxication. 66.9% were chronic (stable lithium dose but changes in other variables such as co-medication). 40.4% took at least one risk medication with a relative contraindication for concurrent lithium treatment. 11.1% of the cases with a high therapeutic level showed moderate to severe intoxications. Feverish infections were significantly associated with severe intoxications. Overall, 97.1% (132/136) of patients fully recovered, two had residual but mild symptoms and two died during hospitalization (unlikely related to the intoxication). In 37.5% of patients, no psychiatrist was involved in the management of high lithium levels or intoxication. In these patients, lithium treatment was adjusted or discontinued in 37.3% of the cases compared to 64.7% when a psychiatrist was involved (χ²(1) = 9.683, p = 0.002).

CONCLUSIONS

Patients and medical doctors should be aware of the increased risk of lithium intoxication already within the high therapeutic range and should consider alternative medications without relative contraindications for concurrent lithium use. Involving psychiatrists during or after an intoxication event is associated with more frequent adjustment of the maintenance lithium dose and should be considered in most cases.

No influence of mineralocorticoid and glutamatergic NMDA receptor stimulation on spatial learning and memory in individuals with major depression

BACKGROUND

Major depressive disorder (MDD) is associated with impairments in spatial learning and memory and with altered functioning of central mineralocorticoid receptors (MR) and glutamatergic N-methyl-D-aspartate receptors (NMDA-R). Both receptors are highly expressed in the hippocampus and prefrontal cortex - brain areas that are critical for spatial learning and memory. Here, we examined the effects of separate and combined MR and NMDA-R stimulation on spatial learning and memory in individuals with MDD and healthy controls.

METHODS

We used a randomized, double-blind, placebo-controlled between-group study design to examine the effects of separate and combined stimulation of the MR (with 0.4 mg fludrocortisone) and NMDA-R (with 250 mg D-cycloserine) in 116 unmedicated individuals with MDD (mean age: 34.7 ± 13.3 years; 78.4% women) and 116 age-, sex-, and education-matched healthy controls. Participants were randomly assigned to one of four conditions: 1) placebo; 2) MR stimulation; 3) NMDA-R stimulation; and 4) combined MR/NMDA-R stimulation. Three hours after drug administration, spatial learning and memory were assessed using a virtual Morris Water Maze task.

RESULTS

Individuals with MDD and healthy controls did not differ in spatial learning and memory performance. Neither separate nor combined MR or NMDA-R stimulation altered measures of spatial performance.

CONCLUSION

In this study of relatively young, predominantly female, and unmedicated individuals, we found no effect of MDD and no effect of separate or combined MR and NMDA-R stimulation on spatial learning and memory.

Patients' Perspectives on Artificial Intelligence in Dentistry: A Controlled Study

Background: As artificial intelligence (AI) becomes increasingly important in modern dentistry, we aimed to assess patients’ perspectives on AI in dentistry specifically for radiographic caries detection and the impact of AI-based diagnosis on patients’ trust. Methods: Validated questionnaires with Likert-scale batteries (1: “strongly disagree” to 5: “strongly agree”) were used to query participants’ experiences with dental radiographs and their knowledge/attitudes towards AI as well as to assess how AI-based communication of a diagnosis impacted their trust, belief, and understanding. Analyses of variance and ordinal logistic regression (OLR) were used (p < 0.05). Results: Patients were convinced that “AI is useful” (mean Likert ± standard deviation 4.2 ± 0.8) and did not fear AI in general (2.2 ± 1.0) nor in dentistry (1.6 ± 0.8). Age, education, and employment status were significantly associated with patients’ attitudes towards AI for dental diagnostics. When shown a radiograph with a caries lesion highlighted by an arrow, patients recognized the lesion significantly less often than when using AI-generated coloured overlays highlighting the lesion (p < 0.0005). AI-based communication did not significantly affect patients’ trust in dentists’ diagnosis (p = 0.44; OLR). Conclusions: Patients showed a positive attitude towards AI in dentistry. AI-supported diagnostics may assist communicating radiographic findings by increasing patients’ ability to recognize caries lesions on dental radiographs.

Approach-avoidance tendencies in depression and childhood trauma: No effect of noradrenergic stimulation

Adverse childhood experiences (ACE) are a major risk factor for major depressive disorder (MDD) in later life. Both conditions are characterized by dysregulations in the noradrenergic system related which again could represent a mediating mechanism for deficits in affective processing and behavioral functioning. In this double-blind, placebo-controlled study we tested the hypothesis that ACE and MDD are characterized by aberrant approach-avoidance (AA) tendencies and that these are mitigated after noradrenergic stimulation with yohimbine. In a mixed-measures, fully crossed design, participants (N = 131, 73 women) with/without MDD and with/without ACE received a single-dose of yohimbine or placebo on different days, followed by an AA task. We found modulation of AA tendencies by the emotional valence of target images, yet there were no effects of group or treatment. From these results, we conclude that AA tendencies are not critically affected by MDD or ACE and that the noradrenergic system is not substantially involved in this behavior.

Selective attention to emotional stimuli and emotion recognition in patients with major depression: The role of mineralocorticoid and glutamatergic NMDA receptors

BACKGROUND

Mineralocorticoid receptors (MR) are highly expressed in limbic brain areas and prefrontal cortex, which are closely related to selective attention to emotional stimuli and emotion recognition. Patients with major depressive disorder (MDD) show alterations in MR functioning and both cognitive processes. MR stimulation improves cognitive processes in MDD and leads to glutamate release that binds upon N-methyl-D-aspartate receptors (NMDA-R).

AIMS

We examined (1) whether MR stimulation has beneficial effects on selective attention to emotional stimuli and on emotion recognition and (2) whether these advantageous effects can be improved by simultaneous NMDA-R stimulation.

METHODS

We examined 116 MDD patients and 116 healthy controls matched for age (M = 34 years), sex (78% women), and education in the following conditions: no pharmacological stimulation (placebo), MR stimulation (0.4 mg fludrocortisone + placebo), NMDA-R stimulation (placebo + 250 mg D-cycloserine (DCS)), MR + NMDA-R stimulation (fludrocortisone + DCS). An emotional dot probe task and a facial emotion recognition task were used to measure selective attention to emotional stimuli and emotion recognition.

RESULTS

Patients with MDD and healthy individuals did not differ in task performance. MR stimulation had no effect on both cognitive processes in both groups. Across groups, NMDA-R stimulation had no effect on selective attention but showed a small effect on emotion recognition by increasing accuracy to recognize angry faces.

CONCLUSIONS

Relatively young unmedicated MDD patients showed no depression-related cognitive deficits compared with healthy controls. Separate MR and simultaneous MR and NMDA-R stimulation revealed no advantageous effects on cognition, but NMDA-R might be involved in emotion recognition.

Yohimbine-Induced Reactivity of Heart Rate Variability in Unmedicated Depressed Patients With and Without Adverse Childhood Experience

Stressful life events play a role in the pathogenesis of major depressive disorder (MDD) and many patients with MDD were exposed to developmental stress due to adverse childhood experiences (ACE). Furthermore, dysregulation of the autonomic nervous system and higher incidence of cardiovascular disease are found in MDD. In MDD, and independently in individuals with ACE, abnormalities in heart rate variability (HRV) have been reported. While these are often confounded, we systematically investigated them with a study which included MDD patients with/without ACE as well as healthy individuals with/without ACE. With this study, we investigated the influence of noradrenergic stimulation on HRV reactivity in unmedicated participants in a randomized, double-blind, repeated measures design. Our sample consisted of men and women with MDD and ACE (n = 25), MDD without ACE (n = 24), healthy participants with ACE (n = 27), and without ACE (n = 48). Participants received a 10 mg single dose of the alpha-2 antagonist yohimbine that increases noradrenergic activity or placebo on 2 separate days, with ECG recordings before and after drug administration at defined intervals. We found lower basal HRV in MDD and ACE: patients with MDD had reduced RMSSD whereas participants with ACE had lower LF-HRV. Contrary to our hypothesis, there was no effect of yohimbine. With this study, we were able to replicate previous findings on HRV differences in MDD and ACE. From the null effect of yohimbine, we conclude that the yohimbine-induced sympathetic activation is not a significant driver of HRV in MDD and ACE.

No association between major depression with and without childhood adversity and the stress hormone copeptin

Background: Adverse childhood experiences (ACE) are associated with an increased risk of major depressive disorder (MDD) and hypothalamic-pituitary-adrenal (HPA) axis dysregulation. Within the HPA axis, corticotropin-releasing hormone and vasopressin (AVP) synergistically stimulate the release of adrenocorticotropic hormone, which promotes cortisol release. The cleavage product copeptin is produced during AVP synthesis and is a surrogate marker of AVP release. Children with ACE and young adults with depressive symptoms have higher levels of copeptin than healthy controls. Objective: To uncover the effects of MDD and ACE on copeptin levels in adult females. Methods: We recruited 94 women (mean age: 34.0 ± 3.6 years): 23 with MDD and ACE, 24 with MDD without ACE, 22 with ACE without MDD, and 25 healthy controls. ACE was defined as repeated sexual or physical abuse at least once a month over at least one year before the age of 18 years. MDD was defined by the DSM-IV criteria. Copeptin plasma levels were measured with an immunoluminometric assay. Results: The four groups did not differ in demographic variables. We found a significant negative correlation between body mass index (BMI) and copeptin plasma levels (r = -.21; p = .045). Copeptin plasma levels did not differ between the four groups after controlling for BMI. Conclusion: Neither MDD nor ACE was associated with altered plasma copeptin levels. Thus, copeptin does not seem to play a major role in MDD and ACE in adult females.

Noradrenergic system and cognitive flexibility: Disentangling the effects of depression and childhood trauma

Stress plays a fundamental role in the development and maintenance of major depressive disorder (MDD). Importantly, maladaptive changes in the physiological stress regulation systems have been demonstrated. In the locus coeruleus-noradrenergic (LC-NA) system, up-regulated central alpha2-adrenergic receptors in patients with MDD affect cognitive functions. Although cognitive deficits are core symptoms of MDD, the relationship between the LC-NA system and cognitive processes has rarely been investigated in depressed patients. The aim of our study was to investigate whether noradrenergic stimulation affects cognitive flexibility in MDD. In addition, we aimed to further disentangle the effects of MDD and adverse childhood experiences (ACE), such as physical or sexual abuse on cognitive function. In a double-blind placebo-controlled study, MDD patients with ACE, MDD patients without ACE, healthy participants with ACE and healthy control participants without MDD or ACE were tested with a task switching task (total N = 125). Participants were tested twice after treatment with either 10 mg yohimbine or a placebo. Switch costs (differences between switch and repetition trials) in reaction times and accuracy served as the independent variables. We found higher switch costs in MDD patients as compared with controls, while ACE did not affect task performance. Yohimbine administration had no effect on task switching. The results of this study contribute to a better understanding of the role of the LC-NA system as a neurobiological mechanism of cognitive processes in patients with MDD.

Delayed effects of psychosocial stress on risk taking

Several studies found that acute stress leads to increased risk taking in humans. However, this effect appears to be time-dependent because the few studies that examined delayed (>40 min after stress onset) stress effects show in fact a decrease in risk taking. In 32 young healthy women, we intra-individually examined whether psychosocial stress decreases risk taking 80 min after stress induction. All participants performed the Balloon Analog Risk Task (BART) twice: once after exposure to the Trier social stress test (TSST) and once after a control condition Placebo-TSST (P-TSST). The experimental order was randomized across participants. The psychophysiological stress response increased after the TSST compared to the P-TSST, indicated by elevated cortisol concentrations, elevated alpha-amylase activity, and elevated blood pressure. We found a significant interaction of stress condition and experimental order. Compared to the control condition psychosocial stress decreased risk taking in novel decision situations but not when participants were already familiar with the BART from the prior condition. Delayed effects of psychosocial stress lead to a decrease in risk taking in unfamiliar but not familiar conditions 80 min after stress exposure. Lay summary It has been suggested that stress exerts delayed effects on risk taking propensity. We found that individuals who are exposed to psychosocial stress take less risk when confronted with novel decisions even 80 min after the stressor compared to individuals who are not stressed.

Effects of mineralocorticoid-receptor stimulation on risk taking behavior in young healthy men and women

Risk taking is influenced by stress, with riskier decisions after exposure to an acute stressor and consecutively elevated cortisol levels. In the brain, cortisol acts on two receptors with different functional profiles: the glucocorticoid receptor (GR) and the mineralocorticoid receptor (MR). In the current study we investigated the effect of MR stimulation on risk taking behavior in 80 young healthy participants (40 women, mean age=23.9). We administered 0.4mg fludrocortisone, a MR agonist, in a between-subjects, placebo controlled design. Subsequently, participants conducted an established risk taking paradigm, the Balloon-Analogue-Risk-Task (BART). We also used two questionnaires to assess risk taking and decision behavior as trait measures. We found a treatment effect with riskier decisions in the fludrocortisone group. Furthermore, we found a sex effect with more risk taking in men. There was no statistically significant interaction between both factors. Our results indicate that acute MR stimulation leads to riskier decisions in women and men. Our findings argue for an important role of the MR in decision making processes.

Mineralocorticoid receptor stimulation effects on spatial memory in healthy young adults: A study using the virtual Morris Water Maze task

OBJECTIVES

Stress hormones such as cortisol are known to influence a wide range of cognitive functions, including hippocampal based spatial memory. In the brain, cortisol acts via two different receptors: the glucocorticoid (GR) and the mineralocorticoid receptor (MR). As the MR has a high density in the hippocampus, we examined the effects of pharmacological MR stimulation on spatial memory.

METHODS

Eighty healthy participants (40 women, 40 men, mean age=23.9years±SD=3.3) completed the virtual Morris Water Maze (vMWM) task to test spatial encoding and spatial memory retrieval after receiving 0.4mg fludrocortisone, a MR agonist, or placebo.

RESULTS

There was no effect of MR stimulation on spatial encoding during the vMWM task. However, participants who received fludrocortisone exhibited improved spatial memory retrieval performance. There was neither a main effect of sex nor a sex-by-treatment interaction.

CONCLUSION

In young healthy participants, MR stimulation improved hippocampal based spatial memory retrieval in a virtual Morris Water Maze task. Our study not only confirms the importance of MR function in spatial memory, but suggests beneficial effects of acute MR stimulation on spatial memory retrieval in humans.

Effects of two dominance manipulations on the stress response: Cognitive and embodied influences

In response to stress, physiological and mental resources are allocated towards those systems that are needed for rapid responding in terms of fight or flight. On the other hand, long term regenerative processes such as growth, digestion and reproduction are attenuated. Levels of the sex steroid testosterone are reduced in participants that suffer from chronic stress. However, beyond its role for reproductive functions, testosterone plays an important role in the regulation of social status and dominance, testosterone levels increase during competition or when the social status is challenged. The Trier Social Stress Test (TSST), a laboratory stressor with a substantial social-evaluative component, can provoke an increase in salivary testosterone levels. Still, so far the reported findings regarding acute stress effects on testosterone are equivocal, possibly due to moderating effects. In this study we experimentally manipulated social dominance in 56 healthy participants (28m) by two independent manipulations (body posture and cognitive role taking) and subjected them to the TSST. We analyzed salivary testosterone and cortisol levels as dependent measures for the endocrine stress response. The role taking manipulation interacted with the testosterone response: we found the strongest increase when participants had to put themselves in a dominant (vs. submissive) role. Our results suggest that transient changes in testosterone levels during stress reflect a response to status threat that is affected by social dominance.

Eyelid contour detection and tracking for startle research related eye-blink measurements from high-speed video records

Using the positions of the eyelids is an effective and contact-free way for the measurement of startle induced eye-blinks, which plays an important role in human psychophysiological research. To the best of our knowledge, no methods for an efficient detection and tracking of the exact eyelid contours in image sequences captured at high-speed exist that are conveniently usable by psychophysiological researchers. In this publication a semi-automatic model-based eyelid contour detection and tracking algorithm for the analysis of high-speed video recordings from an eye tracker is presented. As a large number of images have been acquired prior to method development it was important that our technique is able to deal with images that are recorded without any special parametrisation of the eye tracker. The method entails pupil detection, specular reflection removal and makes use of dynamic model adaption. In a proof-of-concept study we could achieve a correct detection rate of 90.6%. With this approach, we provide a feasible method to accurately assess eye-blinks from high-speed video recordings.