Reduced vagal activity in borderline personality disorder is unaffected by intranasal oxytocin administration, but predicted by the interaction between childhood trauma and attachment insecurity

Beyond clinical observations: a scoping review of AI-detectable observable cues in borderline personality disorder

Borderline Personality Disorder (BPD), impacting approximately 2% of adults worldwide, presents a formidable challenge in psychiatric diagnostics. Often underdiagnosed or misdiagnosed, BPD is associated with high morbidity and mortality. This scoping review embarks on a comprehensive exploration of observable cues in BPD, encompassing language patterns, speech nuances, facial expressions, nonverbal communication, and physiological measurements. The findings unveil distinctive features within the BPD population, including language patterns emphasizing external viewpoints and future tense, specific linguistic characteristics, and unique nonverbal behaviors. Physiological measurements contribute to this exploration, shedding light on emotional responses and physiological arousal in individuals with BPD. These cues offer the potential to enhance diagnostic accuracy and complement existing diagnostic methods, enabling early identification and management in response to the urgent need for precise psychiatric care in the digital era. By serving as possible digital biomarkers, they could provide objective, accessible, and stress-reducing assessments, representing a significant leap towards improved psychiatric assessments and an invaluable contribution to the field of precision psychiatry.

Metabolic Dysfunctions, Dysregulation of the Autonomic Nervous System, and Echocardiographic Parameters in Borderline Personality Disorder: A Narrative Review

Borderline personality disorder (BPD) is a complex psychiatric disorder characterized by an unstable sense of self and identity, emotional dysregulation, impulsivity, and disturbed interpersonal relationships. This narrative review examines the interplay between dysregulation of the autonomic nervous system, metabolic changes, and cardiovascular risk in BPD. Altered heart rate variability (HRV), reflecting the dysregulation of the autonomic nervous system, is associated with some BPD core symptoms, such as emotional instability and impulsivity. Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, often stemming from early trauma, contributes to chronic inflammation and elevated allostatic load, which further increases cardiovascular risk. Metabolic dysfunctions in BPD, such as elevated body mass index (BMI), high blood pressure, and inflammatory markers like C-reactive protein (CRP), exacerbate these risks. Speckle-tracking echocardiography, particularly global longitudinal strain (GLS) and biomarkers such as homocysteine and epicardial fat, could be considered early predictors of cardiovascular events in individuals with BPD. Chronic stress, inflammation, and maladaptive stress responses further heighten cardiovascular vulnerability, potentially accelerating biological aging and cognitive decline. A literature search covering the period from 2014 to 2024 on PubMed identified 189 studies on this topic, of which 37 articles were deemed eligible for this review. These included cross-sectional, longitudinal, case-control, randomised controlled trials (RCTs), reviews, and meta-analysis designs, with sample sizes ranging from 14 to 5969 participants. The main limitations were that only one database was searched, the time of publications was limited, non-English manuscripts were excluded, and the quality of each paper was not commented on. This narrative review aims to provide an overview of recent evidence obtained on this topic, pointing out a direction for future research.

High frequency heart rate variability is associated with sensitivity to affective touch

C-tactile afferents (CTs) are a class of unmyelinated, mechanosensitive nerve fibre that respond optimally to skin temperature, slow moving touch typical of a caress. They are hypothesised to signal the rewarding value of affiliative tactile interactions. While CT firing frequency is positively correlated with subjective ratings of touch pleasantness, trait differences in sensitivity to the specific hedonic value of CT targeted touch have been reported. Inter-individual differences in vagally mediated, high frequency heart rate variability (HF-HRV) have been linked to variation in visual social cognition. Thus, the aim of the present study was to examine the relationship between resting state HF-HRV and sensitivity to socially relevant CT targeted touch. 58 healthy participants first had a 5-minute electrocardiogram. They then rated the pleasantness of 5 randomly presented velocities of robotically delivered touch. Three velocities fell within (1, 3, 10 cm/s) and two outside (0.3, 30 cm/s) the CT optimal range. Each velocity was delivered twice. On a group level, affective touch ratings were described by a negative quadratic function, with CT optimal velocities rated as more pleasant than slower and faster speeds. Simple regression analysis confirmed participants' HF-HRV was significantly predicted by the quadratic curve fit of their touch ratings, with higher HF-HRV associated with a better quadratic fit. These findings indicate that, in line with previous observations that higher HF-HRV is associated with enhanced sensitivity to visual social cues, trait differences in autonomic control could account for previously reported individual differences in CT sensitivity.

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.

Baroreflex sensitivity is associated with markers of hippocampal gliosis and dysmyelination in patients with psychosis

PURPOSE

Hippocampal dysfunction plays a key role in the pathology of psychosis. Given hippocampal sensitivity to changes in cerebral perfusion, decreased baroreflex function could contribute to psychosis pathogenesis. This study had two aims: (1) To compare baroreflex sensitivity in participants with psychosis to two control groups: participants with a nonpsychotic affective disorder and participants with no history of psychiatric disease; (2) to examine the relationship between hippocampal neurometabolites and baroreflex sensitivities in these three groups. We hypothesized that baroreflex sensitivity would be reduced and correlated with hippocampal neurometabolite levels in participants with psychosis, but not in the control groups.

METHODS

We assessed baroreflex sensitivity during the Valsalva maneuver separated into vagal and adrenergic components. Metabolite concentrations for cellular processes were quantitated in the entire multivoxel hippocampus using H¹-MR spectroscopic (MRS) imaging and were compared with baroreflex sensitivities in the three groups.

RESULTS

Vagal baroreflex sensitivity (BRS-V) was reduced in a significantly larger proportion of participants with psychosis compared with patients with nonpsychotic affective disorders, whereas participants with psychosis had increased adrenergic baroreflex sensitivity (BRS-A) compared with participants with no history of psychiatric disease. Only in psychotic cases were baroreflex sensitivities associated with hippocampal metabolite concentrations. Specifically, BRS-V was inversely correlated with myo-inositol, a marker of gliosis, and BRS-A was positively correlated with energy dependent dysmyelination (choline, creatine) and excitatory activity (GLX).

CONCLUSIONS

Abnormal baroreflex sensitivity is common in participants with psychosis and is associated with MRS markers of hippocampal pathology. Future longitudinal studies are needed to examine causality.