Dorsolateral prefrontal cortex and hippocampus sustain impulsivity and aggressiveness in borderline personality disorder

Trait Impulsivity as a Feature of Parkinson's Disease Treatment and Progression

Heightened trait impulsivity in both subclinical and pathological senses is becoming increasingly recognised in Parkinson's disease (PD). Impulsive behaviours and impulse control disorders (ICDs) are a consequence of perturbation to the rewards pathway leading individuals to conduct activities in a repetitive, excessive, and maladaptive fashion. Commonly linked to PD, heightened trait impulsivity has been found to primarily manifest in the forms of hypersexuality, pathological gambling, compulsive shopping, and binge eating, all of which may significantly impact social and financial standing. Subsequent burden to quality of life for both individuals with PD and caregivers are common. Although risk factors and indicators for ICDs in PD are currently lacking, it is recognised that the condition is often precipitated by dopamine replacement therapies, primarily dopamine agonist administration. While this nonmotor symptom is being increasingly diagnosed in PD populations, it remains relatively elusive in comparison to its motor counterparts. Through discussion of impulsivity characteristics, neuroanatomy, and neurochemistry, in addition to reviewing existing research on the potential contributing factors to impulsivity in PD, this review highlights impulsivity as a significant and detrimental PD symptom. Thus, emphasising the imperative need to establish efficacious diagnostic tools and treatments.

What impact can brain stimulation interventions have on borderline personality disorder?

INTRODUCTION

Borderline personality disorder (BPD) is a severe mental disorder characterized by emotion dysregulation, impulsivity, neuropsychological impairment, and interpersonal instability, presenting with multiple psychiatric comorbidities, functional disability and reduced life expectancy due suicidal behaviors.

AREAS COVERED

In this perspective, the authors explore the application of noninvasive brain stimulation (NIBS) (rTMS, tDCS, and MST) in BPD individuals by considering a symptom-based approach, focusing on general BPD psychopathology, impulsivity and neuropsychological impairments, suicidality and depressive/anxious symptoms, and emotion dysregulation.

EXPERT OPINION

According to a symptoms-based approach, NIBS interventions (particularly rTMS and tDCS) are promising treatment options for BPD individuals improving core symptoms such as emotional and behavioral dysregulation, neuropsychological impairments and depressive symptoms. However, the heterogeneity of stimulation protocols and of assessment tools used to detect these changes limits the possibility to provide definitive recommendations according to a symptom-based approach. To implement such armamentarium in clinical practice, future NIIBS studies should further consider a lifespan perspective due to clinical variability over time, the role of psychiatric comorbidities affecting BPD individuals and the need to combine NIBS with specialized psychotherapeutic approaches for BPD patients and with functional neuroimaging studies.

Theta burst stimulation add on to dialectical behavioral therapy in borderline-personality-disorder: methods and design of a randomized, single-blind, placebo-controlled pilot trial

Specialized psychotherapeutic treatments like dialectical behavioral therapy (DBT) are recommended as first treatment for borderline personality disorder (BPD). In recent years, studies have emerged that focus on repetitive transcranial magnetic stimulation (rTMS) in BPD. Both have independently demonstrated efficacy in the treatment of BPD. Intermitted theta burst stimulation (iTBS), a modified design of rTMS, is thought to increase the excitability of neurons and could be a supplement to psychotherapy in addition to being a standalone treatment. However, no studies to date have investigated the combination of DBT and rTMS/iTBS. This study protocol describes the methods and design of a randomized, single-blinded, sham-controlled clinical pilot study in which BPD patients will be randomly assigned to either iTBS or sham during four consecutive weeks (20 sessions in total) in addition to standardized DBT treatment. The stimulation will focus on the unilateral stimulation of the left dorsolateral prefrontal cortex (DLPFC), which plays an important role in the control of impulsivity and risk-taking. Primary outcome is the difference in borderline symptomatology, while secondary target criteria are depressive symptoms, general functional level, impulsivity and self-compassion. Statistical analysis of therapy response will be conducted by Mixed Model Repeated Measurement using a 2 × 2-factorial between-subjects design with the between-subject factor stimulation (TMS vs. Sham) and the within-subject factor time (T0 vs. T1). Furthermore, structural magnetic resonance imaging (MRI) will be conducted and analyzed. The study will provide evidence and insight on whether iTBS has an enhancing effect as add-on to DBT in BPD.Trial registration: drks.de (DRKS00020413) registered 13/01/2020.

Sense of agency and its disturbances: A systematic review targeting the intentional binding effect in neuropsychiatric disorders

Sense of agency (SoA) indicates a person's ability to perceive her/his own motor acts as actually being her/his and, through them, to exert control over the course of external events. Disruptions in SoA may profoundly affect the individual's functioning, as observed in several neuropsychiatric disorders. This is the first article to systematically review studies that investigated intentional binding (IB), a quantitative proxy for SoA measurement, in neurological and psychiatric patients. Eligible were studies of IB involving patients with neurological and/or psychiatric disorders. We included 15 studies involving 692 individuals. Risk of bias was low throughout studies. Abnormally increased action-outcome binding was found in schizophrenia and in patients with Parkinson's disease taking dopaminergic medications or reporting impulsive-compulsive behaviors. A decreased IB effect was observed in Tourette's disorder and functional movement disorders, whereas increased action-outcome binding was found in patients with the cortico-basal syndrome. The extent of IB deviation from healthy control values correlated with the severity of symptoms in several disorders. Inconsistent effects were found for autism spectrum disorders, anorexia nervosa, and borderline personality disorder. Findings pave the way for treatments specifically targeting SoA in neuropsychiatric disorders where IB is altered.

Effects of childhood trauma on aggressive behaviors and hippocampal function: the modulation of COMT haplotypes

Background

Aggression is a commonly hostile behavior linked to the hippocampal activity. Childhood trauma (CT) exposure has been associated with altered sensitization of the hypothalamic-pituitary-adrenal (HPA) axis and hippocampal volume，which could increase violent aggressive behaviors. Additionally, Catechol-O-methyltransferase (COMT), the major dopamine metabolism enzyme, is implicated in stress responsivity, including aggression. Hence, CT exposure may affect aggression through the effect on the hippocampal function, which might also be modulated by the COMT variations.

Objectives

This study examined whether both CT and haplotypes of COMT moderate hippocampal function and thus affect human aggressive behavior.

Methods

We obtained bilateral hippocampal functional connectivity maps using resting state functional magnetic resonance imaging (MRI) data. COMT haplotype estimation was performed using Haploview 4.2 and PHASE 2.1. Then we constructed a moderated mediation model to study the effect of the CTQ × COMT on aggressive behavior.

Results

Three major haplotypes were generated from thirteen single nucleotide polymorphisms (SNPs) within the COMT gene and formed three haplotypes corresponding to high, medium, and low enzymatic activity of COMT. The results showed interactive relationships between the Childhood Trauma Questionnaire (CTQ) and COMT with respect to the functional connectivity (FC) of the bilateral hippocampus (HIP)-orbital frontal cortex (OFC). Specifically, CT experience predicted lower negative HIP-OFC coupling in the APS and HPS haplotypes corresponding to the medium and high enzymatic activity of COMT, but greater FC in the LPS haplotypes corresponding to the low enzymatic activity. We also observed a conditional mediation effect of the right HIP-OFC coupling in the link between COMT and aggressive behavior that was moderated by CT experience.

Conclusions

These results suggest that CT and COMT have a combined effect on aggressive behavior through hippocampal function. This mediation analysis sheds light on the influence of childhood experience on aggressive behavior in different genetic backgrounds.

Impaired decision-making in borderline personality disorder

Introduction

Borderline personality disorder (BPD) is a complex mental disorder with core symptoms like interpersonal instability, emotion dysregulation, self-harm, and impulsive decision-making. Previous neuropsychological studies have found impairment in the decision-making of patients with BPD related to impulsivity. In our study, we focus on a better, more nuanced understanding of impulsive decision-making in BPD with the help of Rogers' decision-making test that simulates a gambling situation.

Methods

A novelty of our study is that we excluded from further analysis non-compliant participants based on their performance. Outlier participants on the measures proportion of good choices and average of wager choice number were filtered out to represent the population that understood the basic premise of the task and showed minimal motivation to gain rewards. Thus participants often choosing the less likely color or frequently choosing the first bet amount available (to probably speed up the test) were omitted from further analysis. Another novelty is that we assessed and reported six variables that examine Deliberation Time, Quality of Decision, Risk-taking, Overall proportion bet, Delay aversion, and Risk adjustment. Forty-three women with BPD participated in the study, and 16 non-compliant were excluded. As for the healthy control group, 42 women participated in the study, and four non-compliant were excluded. Thus, we compared the data of 27 patients with BPD with 38 healthy controls.

Results

Our results show that there are significant differences amongst the groups regarding the Quality of Decision Making (F (1,63) = 5.801, p = 0.019) and Risk Adjustment (F (1,63) = 6.522, p = 0.013). We also found significant interactions between group and winning probability regarding Risk Taking (F (4,252) = 4.765 p = 0.001) and Overall proportion of bets, i.e., the average proportion of bets relative to the total score of the subject (F (4,252) = 4.505, p = 0.002).

Discussion

Our results show that the two groups use different decision-making strategies that can have various associations with everyday life situations.

Transdiagnostic brain correlates of self-reported trait impulsivity: A dimensional structure-symptom investigation

Impulsivity transcends psychiatric diagnoses and is often related to anhedonia. This ad hoc cross-sectional investigation explored 1) whether self-reported trait impulsivity mapped onto a common structural brain substrate across healthy controls (HCs) and psychiatric patients, and 2) in a more exploratory fashion, whether impulsivity and anhedonia were related to each other and shared overlapping brain correlates. Structural magnetic resonance imaging (sMRI) datasets from 234 participants including HCs (n = 109) and patients with opioid use disorder (OUD, n = 22), cocaine use disorder (CUD, n = 43), borderline personality disorder (BPD, n = 45) and schizophrenia (SZ, n = 15) were included. Trait impulsivity was measured with the Barratt Impulsiveness Scale (BIS-11) and anhedonia with a subscore of the Beck Depression Inventory (BDI). BIS-11 global score data were available for the entire sample, while data on the BIS-11 2nd order factors attentional, motor and non-planning were additionally in hand for a subsample consisting of HCs, OUD and BPD patients (n = 116). Voxel-based morphometry analyses were conducted for identifying dimensional associations between grey matter volume and impulsivity/anhedonia. Partial correlations were further performed to exploratory test the relationships between impulsivity and anhedonia and their corresponding volumetric brain substrates. Volume of the left opercular part of the inferior frontal gyrus (IFG) was negatively related to global impulsivity across the entire sample and specifically to motor impulsivity in the subsample of HCs, OUD and BPD patients. Across patients anhedonia expression was negatively correlated with left putamen volume. Although there was no relationship between global impulsivity and anhedonia across all patients, only across OUD and BPD patients anhedonia was positively associated with attentional impulsivity. Finally, also across OUD and BPD patients, motor impulsivity associated left IFG volume was positively linked with anhedonia-associated volume in the left putamen. Our findings suggest a critical role of left IFG volume in self-reported global impulsivity across healthy participants and patients with substance use disorder, BPD and SZ. Preliminary findings in OUD and BPD patients further suggests associations between impulsivity and anhedonia that are related to grey matter reductions in the left IFG and putamen.

The effect of microbiome composition on impulsive and violent behavior: A systematic review

The impact of the microbiome on brain function and behavior has recently become an important research topic. We searched for a link between the gut microbiome and impulsive and violent behavior. We focused on critical factors influencing the microbiome establishment that may affect human health later in life, i.e., delivery mode, early-life feeding, and early antibiotic exposure. We searched PubMed, Web of Science, and the Cochrane Library. We included original human studies examining adults and children with impulsive and/or violent behavior that assessed the gut microbiota composition of participants, delivery mode, infant feeding mode, or early antibiotic exposure. Bibliographic searches yielded 429 articles, and 21 met the eligibility criteria. Two studies reported data on patients with schizophrenia with violent behavior, while 19 studies reported data on patients with attention-deficit hyperactivity disorder (ADHD). The results showed several bacterial taxa associated with ADHD symptomatology and with violent behavior in patients with schizophrenia. No association was found between delivery mode and impulsive behavior, nor did any articles relate infant feeding mode to violent human behavior. Those studies investigating early antibiotic exposure yielded ambiguous results. The heterogeneity of the data and the different methodologies of the included studies limited the external validity of the results. We found few studies that addressed the possible microbiome involvement in the pathophysiology of impulsive and violent behavior in humans. Our review revealed a gap in knowledge regarding links between the gut microbiome and these extreme behavioral patterns.

Personality disorder and mild traumatic brain injury

Mild traumatic brain injury (mTBI) poses risk to the neurocognitive, emotional, and financial well-being of affected individuals. While aggression and impulsivity have been examined in relation to mTBI, little work has been done to evaluate the relationship between history of mTBI and personality disorder (PD). The authors examined the associations between history of mTBI and PD in a control group without history of mTBI (N = 1189) and individuals with history of mTBI (N = 267). Results demonstrated that any PD diagnosis is a significant risk factor for mTBI (p < 0.001). Cluster B diagnoses, particularly borderline and antisocial PD, were independently significant risk factors for mTBI. These data suggest a role for screening for a history of mTBI in patients with PDs and associated traits.

Efficacy of Noninvasive Brain Stimulation on Borderline Personality Disorder Core Symptoms: A Systematic Review

Although psychotherapy is the first-line treatment of borderline personality disorder (BPD), psychopharmacological agents have not been approved yet. Modulating brain functions with noninvasive brain stimulation (NIBS) interventions, such as repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), may have a role in the treatment of BPD. In light of the limited knowledge available and the emerging interest in the possible role of NIBS as a therapeutic tool, the authors' main aim is to systematically review the literature on the effect of both rTMS and tDCS on BPD symptoms, specifically affective dysregulation, impulsive-behavioral dyscontrol, and cognitive-perceptual difficulties. The review process was conducted in accordance with PRISMA guidelines. The research methods were registered on PROSPERO (id code CRD42020209491). Eleven studies were included in the review. Despite the limited number of studies retrieved, preliminary data showed an improvement in all domains. Further studies are needed to understand potential long-term advantages of NIBS.

Effects of pharmacological treatments on neuroimaging findings in borderline personality disorder: A review of FDG-PET and fNIRS studies

BACKGROUND

Borderline personality disorder (BPD) is a serious mental condition characterized by instability in identity, interpersonal relationships, emotion regulation and impulsivity. These symptoms seem to be associated to specific brain alterations, which have been largely investigated. In particular, positron emission tomography (PET) and functional near-infrared spectroscopy (fNIRS) have demonstrated abnormalities in brain metabolism and hemodynamics in BPD, specifically in the fronto-limbic system. However, the role of medications on brain metabolism and hemodynamics in BPD is still largely unknown.

METHODS

We conducted a search on PubMed, Scopus and Web of Science of PET and fNIRS studies exploring the effect of medications on brain metabolism and hemodynamics in BPD. A total of 10 studies met the inclusion criteria.

RESULTS

Overall, PET studies showed an effect of psychotropic agents on brain metabolism, especially in frontal and temporal areas. Also, higher metabolic rates in frontal areas were found to correlate with clinical improvements. In contrast, fNIRS investigations reported an inconclusive or absent effects on brain hemodynamics in BPD patients.

LIMITATIONS

The small sample size, the elevated percentage of women, the heterogeneity in pharmacological agents and the presence of comorbidities limit the conclusions of the present review.

CONCLUSIONS

Serotoninergic agents and second-generation antipsychotics produce changes in frontal and temporal metabolism in BPD, which appear to correlate with clinical improvements. Differently, brain hemodynamics do not seem to be significantly affected by the most commonly prescribed drugs in BPD, suggesting that the therapeutic actions of medications are not mediated by changes in neural hemodynamics.

Efficacy and tolerability of Brain Stimulation interventions in Borderline Personality Disorder: state of the art and future perspectives - A systematic review

Treating Borderline Personality Disorder (BPD) is a major challenge for psychiatrists. As Brain Stimulation represents an alternative approach to treat psychiatric disorders, our systematic review is the first to focus on both invasive and Non-Invasive Brain Stimulation (NIBS) interventions in people living with BPD, examining clinical effects over core features and comorbid conditions. Following PRISMA guidelines, out of 422 original records, 24 papers were included regarding Deep Brain Stimulation (n = 1), Electroconvulsive therapy (n = 5), Transcranial Magnetic Stimulation (n = 13) and transcranial Direct Current Stimulation (n = 5). According to impulsivity and emotional dysregulated domain improvements, NIBS in BPD appears to restore frontolimbic network deficiencies. NIBS seems also to modulate depressive features. Safety and tolerability profiles for each technique are discussed. Despite encouraging results, definitive recommendations on Brain Stimulation in BPD are mitigated by protocols heterogeneity, lack of randomized controlled trials and poor quality of included studies, including high risk of methodological biases. To serve as guide for future systematic investigations, protocols optimization proposals are provided, focusing on alternative stimulation sites and suggesting a NIBS symptom-based approach.

Aggression in borderline personality disorder: A systematic review of neuroimaging studies

Aggressive behaviors are prevalent among patients with Borderline Personality Disorder (BPD). Neuroimaging studies have linked aggression in BPD patients to neurochemical, structural, functional, and metabolic alterations in various brain regions, especially in frontal-limbic areas. This systematic review summarizes current neuroimaging results on aggression among BPD patients and provides an overview of relevant brain mechanisms. A systematic search of PubMed and Web of Science databases, in addition to manual check of references, identified thirty-two eligible articles, including two magnetic resonance spectrum (MRS), thirteen structural magnetic resonance imaging (sMRI), six functional magnetic resonance imaging (fMRI), and eleven positron emission tomography (PET) studies. The reviewed studies have highlighted the abnormalities in prefrontal cortices and limbic structures including amygdala and hippocampus. Less studies have zoomed in the roles of parietal and temporal regions or taken a network perspective. Connectivity studies have shed light on the importance of the frontal-limbic interactions in regulating aggression. Conflicted findings might be attributed to disparity in controlling gender, anatomical subdivisions, and comorbidities, which shall be considered in future studies.

Auditory event-related electroencephalographic potentials in borderline personality disorder

BACKGROUND

Borderline Personality Disorder (BPD) is characterized by mood dysregulation, impulsivity, identity disturbances, and a higher risk for suicide. Currently, the diagnosis is solely based on clinical observation of overt symptoms, and this can delay the detection of the disease and the timely start of appropriate treatment. Several candidate clinical tools have been studied to better characterize BPD, including event-related potentials (ERP). This review aimed at summarizing the results of the available ERP studies on BPD to clarify the possible application of this technique in the early diagnosis of BPD.

METHODS

A bibliographic search on PubMed and PsycInfo was performed in order to identify studies comprising individuals with BPD diagnosis and a control group that evaluated the ERP elicited by auditory stimuli.

RESULTS

Ten studies that explored various ERP components associated with auditory stimuli in BPD were included. Overall, the results showed that positive ERP (P50, P100, and P300) amplitude and latencies as well as loudness dependance were altered in BPD patients compared to controls, possibly reflecting deficits involving attention, mainly at its early stage, and executive functions.

LIMITATIONS

The reviewed studies used different ERP approaches and non-homogeneous BPD diagnostic criteria.

CONCLUSIONS

Auditory ERP appear to be a promising tool for the assessment of BPD patients, especially for early diagnosis and evaluation of cognitive symptoms.

Does Resilience Mediate the Association of Adverse Early Childhood Experiences With Emotional and Behavioural Problems?

Objectives: To explore the role of resilience as a mediator in the association between adverse childhood experiences (ACE) and emotional and behavioural problems (EBP) among adolescents.

Methods: We used data from the Slovak 2018 Health Behaviour in School-aged Children study, comprising 2,839 adolescents aged 13–15 (mean age 13.93; 49.6% boys). We used multivariate linear regression performed on 5000 bootstrap samples adjusted for age, gender, family affluence to explore mediation of the associations between ACE (measured using the adapted Adverse Childhood Experience Questionnaire) and EBP (measured using the Strengths and Difficulties Questionnaire) by resilience (measured with the Child and Youth Resilience Measure).

Results: We found ACE [B = 0.78; 95% confidence interval (CI): 0.67|0.90] and resilience (B = −0.73; 95% CI: −0.79|−0.67) to be significantly associated with EBP. The association of ACE and EBP was mediated by resilience. The mediated indirect effect of resilience was ab = 0.25; 95% CI: 0.18|0.32.

Conclusion: Resilience seems to play a mediator role in the relationship between ACE and EBP. Helping adolescents with ACE to build and use internal and external sources of resilience can decrease the negative impact of ACE on EBP.

Does Schoolmate and Teacher Support Buffer against the Effect of Adverse Childhood Experiences on Emotional and Behavioural Problems?

This study aims to explore the associations of schoolmate and teacher support with emotional and behavioural problems (EBP) and whether schoolmate and teacher support affects the associations of adverse childhood experiences (ACE) and of EBP in adolescence. We obtained data from 5220 students aged from 11 to 15 (48.7% boys), who participated in the Health Behaviour in a School-aged Children study (2018, Slovakia). Using logistic regression adjusted for gender, age and family affluence we assessed the modification of the relations of ACE and EBP by schoolmate and teacher support. Schoolmate and teacher support decreased the probability of EBP (Odds Ratios, 95% confidence intervals: 0.76, 0.74|0.79; and 0.86, 0.83|0.89, respectively). However, we found no statistically significant interactions of schoolmate and teacher support regarding the association of ACE with EBP. Schoolmate and teacher support decreased the likelihood of EBP among adolescents but do not buffer the relation of any previous ACE with EBP.

Imaging associations of self-injurious behaviours amongst patients with Borderline Personality Disorder: A mini-review

BACKGROUND

Borderline Personality Disorder (BPD) is a severe and disabling psychiatric syndrome, frequently associated with self-injurious behaviours (SIB). In recent years, functional magnetic resonance imaging (fMRI) investigations have tried to identify alterations associated with SIB amongst BPD patients, in order to better delineate possible neurobiological underpinnings of these manifestations. In this mini-review, we aimed at summarizing fMRI studies exploring patterns of neural activation associated with SIB in BPD patients.

METHODS

Literature searches on PubMed, Psych-Info and Embase databases were performed for all fMRI studies including adult patients with BPD and SIB undergoing different tasks, including painful or thermic stimulation, affective stimulation through the presentation of picturesor the recollection of personal memories as well as tasks that evaluate sustained attention and impulsivity, and reward processing. Thirteen relevant papers were considered eligible for the present review.

RESULTS

Patients with BPD and SIB, compared to HC, showed prefrontal, nucleus accumbens overactivation and amygdala deactivation during pain stimulation. During negative affective stimulation, BPD patients showed a hyperactivation of the amygdala and a hypoactivation of the orbitofrontal cortex (OFC), which was also found to be enhanced during a gambling task and during a recalling of aversive memories. In contrast, during cognitive tasks with negative affective interference, BPD patients showed hypoactivation of OFC, anterior cingulated cortex, and basal ganglia.

LIMITATIONS

The limited number of studies and the heterogeneity regarding the fMRI tasks employed allowed only suggestive conclusions.

CONCLUSIONS

The reviewed fMRI studies highlighted that BPD patients with a history of SIB showed altered brain activity, compared to HC, in regions involved in inhibitory cognitive processes and affect regulation, which may in turn, explain the overwhelming emotional experiences eliciting SIB in these patients.

Repetitive transcranial magnetic stimulation in patients with borderline personality disorder: A systematic review

The literature on the application of repetitive transcranial magnetic stimulation (rTMS) in Borderline Personality Disorder (BPD) is unclear, even though its neuromodulatory effects on underlying neural circuitry involved in BPD symptoms suggest that it could be a potential treatment option. We sought to review the evidence on rTMS as a treatment option in BPD. PubMed (for Medline database), Google Scholar, and Scopus were systematically searched following the PRISMA guidelines for studies of any design examining the application of the rTMS treatment in adult patients with precise and primary diagnosis of BPD written in the English language. The systematic review has been registered on PROSPERO (CRD42020215927). Forty one records were screened, and eight fulfilled inclusion criteria (total of 63 patients). The existing studies suggest that rTMS is a well-tolerated treatment in patients with BPD. Double-blind randomized controlled studies are necessary to help elucidate the effects of rTMS in the different symptoms in BPD and establish efficacy and the best cortical targets and stimulation protocols. Longitudinal studies that combine evidenced based psychotherapy with rTMS may be a future line of investigation that could potentially improve outcomes for this population.

Effects of pharmacological treatments on emotional tasks in borderline personality disorder: A review of functional magnetic resonance imaging studies

BACKGROUND

Borderline personality disorder (BPD) is a common mental disorder characterized by instability in interpersonal relationships, impaired self-image, impulsivity and aggressive behaviors that often requires pharmacological treatments. Neuroimaging alterations have been extensively reported in BPD, especially in regions within the fronto-limbic system. Although medications can be an important confounding factor in functional Magnetic Resonance Imaging (fMRI) studies, their role on brain function in BPD patients still remains uncertain. Therefore, this review aims to improve our understanding on the potential effect of the most commonly prescribed drugs for BPD on brain function during processing of emotional tasks.

METHODS

A search on PubMed, Scopus and Web of Science of fMRI studies exploring the effect of antipsychotics, antidepressants and mood stabilizers on brain activity during processing of emotional tasks on BPD was conducted.

RESULTS

Overall the studies showed small or no effect of pharmacological treatments on brain activity and connectivity in BPD patients during processing of emotional tasks.

LIMITATIONS

The small sample size, the observational design, the elevated percentage of women, the concomitant use of psychostimulants, anticholinergics and opioids substitute treatments and the high rate of comorbidities limit the conclusion of this review.

CONCLUSIONS

Pharmacological treatments seem to have minor role on brain activity/connectivity in BPD patients during emotional tasks, ultimately suggesting that in BPD patients brain deficits seem not be influenced by medications. This might be due to functional brain specificities of BPD and to the differences in pharmacological regimens and compliance to therapy between BPD and other common psychiatric disorders.

Brain gray matter structures associated with trait impulsivity: A systematic review and voxel-based meta-analysis

Trait impulsivity is a multifaceted personality characteristic that contributes to maladaptive life outcomes. Although a growing body of neuroimaging studies have investigated the structural correlates of trait impulsivity, the findings remain highly inconsistent and heterogeneous. Herein, we performed a systematic review to depict an integrated delineation of gray matter (GM) substrates of trait impulsivity and a meta-analysis to examine concurrence across previous whole-brain voxel-based morphometry studies. The systematic review summarized the diverse findings in GM morphometry in the past literature, and the quantitative meta-analysis revealed impulsivity-related volumetric GM alterations in prefrontal, temporal, and parietal cortices. In addition, we identified the modulatory effects of age and gender in impulsivity-GM volume associations. The present study advances understanding of brain GM morphometry features underlying trait impulsivity. The findings may have practical implications in the clinical diagnosis of and intervention for impulsivity-related disorders.

Gray matter correlates of impulsivity in psychopathy and in the general population differ by kind, not by degree: a comparison of systematic reviews

A fundamental question in neuropsychiatry is whether a neurobiological continuum accompanies the behavioral continuum between subclinical and clinical traits. Impulsivity is a trait that varies in the general population and manifests severely in disorders like psychopathy. Is the neural profile of severe impulsivity in psychopathy an extreme but continuous manifestation of that associated with impulsivity in the general population (different by degree)? Or is it discontinuous and unique (different by kind)? Here, we compare systematic reviews of the relationship between impulsivity and gray matter in psychopathy and in the general population. The findings suggest that the neural profile associated with extreme impulsivity in psychopathy (increased gray matter in rostral and ventral striatum and prefrontal cortexes) is distinct from that associated with impulsivity in the general population (decreased gray matter in rostral and ventral prefrontal cortexes). Severe impulsivity in psychopathy may therefore arise from a pathophysiological mechanism that is unique to the disorder. These findings prompt the need for future studies to directly test the effect of group on the impulsivity–gray matter relationship in samples comprised of healthy individuals and individuals with psychopathy. The results caution against the use of community samples to examine impulsive psychopathic traits in relation to neurobiology.

The neurobiology of human aggressive behavior: Neuroimaging, genetic, and neurochemical aspects

In modern societies, there is a strive to improve the quality of life related to risk of crimes which inevitably requires a better understanding of brain determinants and mediators of aggression. Neurobiology provides powerful tools to achieve this end. Pre-clinical and clinical studies show that changes in regional volumes, metabolism-function and connectivity within specific neural networks are related to aggression. Subregions of prefrontal cortex, insula, amygdala, basal ganglia and hippocampus play a major role within these circuits and have been consistently implicated in biology of aggression. Genetic variations in proteins regulating the synthesis, degradation, and transport of serotonin and dopamine as well as their signal transduction have been found to mediate behavioral variability observed in aggression. Gene-gene and gene-environment interactions represent additional important risk factors for aggressiveness. Considering the social burden of pathological forms of aggression, more basic and translational studies should be conducted to accelerate applications to clinical practice, justice courts, and policy making.

Repeated transcranial direct current stimulation of dorsolateral-prefrontal cortex improves executive functions, cognitive reappraisal emotion regulation, and control over emotional processing in borderline personality disorder: A randomized, sham-controlled, parallel-group study

BACKGROUND

Borderline personality disorder (BPD) is primarily characterized by deficient emotion regulation. Impaired cognitive control over negative emotions is central to emotion dysregulation in BPD. Respective executive dysfunctions are associated with hypoactivation of prefrontal regions, and consecutive alterations of fronto-limbic network functionality. Here, we investigated the effect of increasing activity of the dorsolateral prefrontal cortex (DLPFC) with repeated transcranial direct current stimulation (tDCS) on (1) executive dysfunctions and (2) whether improving cognitive control affects emotion dysregulation and emotional processing in BPD.

METHODS

Thirty-two patients diagnosed with BPD were randomly assigned to active stimulation (N = 16) or sham stimulation (N = 16) group in a randomized, sham-controlled, parallel-group design. They received 10 sessions of active (2 mA, 20 min, anodal left- cathodal right DLPFC) or sham tDCS over 10 days. Major executive functions, emotion regulation strategies, and emotional processing of the patients were assessed before and immediately after the intervention.

RESULTS

The active stimulation group showed a significant improvement in major executive function domains. Importantly, cognitive reappraisal strategy of emotion regulation and several factors of emotional processing involved in the control of emotion significantly improved in the active stimulation group after the intervention. Factors related to emotional expression were, however, not affected.

LIMITATIONS

The single-blind design, absence of follow-up measures, and the intrinsically limited focality of tDCS are limitations of this study.

CONCLUSIONS

Increasing activity of the DLPFC improves executive functioning in BPD and improves ´cognitive control over negative emotions. Cognitive control interventions could be a potential, symptom-driven therapeutic approach in BPD.

Does family communication moderate the association between adverse childhood experiences and emotional and behavioural problems?

BACKGROUND

Adverse childhood experiences (ACEs) and poor family support and communication can increase emotional and behavioural problems (EBP). Therefore, we assessed the association of difficult communication with mother and with father separately with both emotional and behavioural problems (EBP), and whether adolescents' communication with mother and with father moderates the association of adverse childhood experiences (ACE) with the EBP of adolescents.

METHODS

We used data from the Health Behaviour in School-aged Children study conducted in 2018 in Slovakia, comprising 5202 adolescents aged from 11 to 15 (mean age 13.53; 49.3% boys). EBP were measured using the Strengths and Difficulties Questionnaire. We used generalized linear regression adjusted for age, gender and family affluence to explore the modification of the associations between ACE and EBP by communication (easy vs. difficult communication) with mother and father.

RESULTS

Difficult communication or a complete lack of communication due to the absence of mother and father increased the probability of emotional (exp (b): 0.96, 95% CI: 0.92|1.00; and 0.95, 95% CI: 0.91|0.99, respectively) and also of behavioural problems (exp (b): 0.96, 95% CI: 0.92|1.00; and 0.94, 95% CI: 0.90|0.97, respectively). We found a statistically significant interaction of communication with father on the association of ACE with EBP, showing that the joint effects were less than multiplicative.

CONCLUSION

Difficult communication with mother and father is related to EBP among adolescents, and adolescents' communication with father moderates the association of ACE with both emotional and behavioural problems among adolescents.

A systematic review of structural MRI investigations within borderline personality disorder: Identification of key psychological variables of interest going forward

Existing models of Borderline Personality Disorder (BPD) suggest that a combination of genetic vulnerability, childhood trauma, and disrupted attachment can lead to the marked emotional lability, impulsivity and interpersonal difficulties observed clinically. Brain structural differences in frontal, limbic and hippocampal regions have been reported in BPD. Less clear is how specific psychological factors relate to these structural differences, and how consistently this is found across studies. This was the focus of the present review. Eighteen studies published between 2004 and 2018 met inclusion criteria encompassing 990 participants. Study quality was assessed using the Nottingham-Ottawa Scale. We also introduce a newly devised scale to assess MRI reporting quality. The most frequently investigated psychological variable were impulsivity (9 studies), depression (8), trauma (6), aggression (6), severity of symptoms (3), global functioning, abuse and dissociation (2). Study quality varied, however, a trend was observed where newer studies were higher in reporting quality. Impulsivity demonstrated greater association with frontal structures, trauma related to the hypothalamus and limbic systems, and aggression with hippocampal and frontal structures. The present review recommends greater exploration of neurocognitive and psychosis-related features such as delusions, paranoia and voice-hearing in future studies, and to investigate cortical changes in longitudinal designs.

Time-varying associations between prenatal metal mixtures and rapid visual processing in children

BACKGROUND

Humans are exposed to mixtures of chemicals across their lifetimes, a concept sometimes called the "exposome." Mixtures likely have temporal "critical windows" of susceptibility like single agents and measuring them repeatedly might help to define such windows. Common approaches to evaluate the effects of chemical mixtures have focused on their effects at a single time point. Our goal is to expand upon these previous techniques and examine the time-varying critical windows for metal mixtures on subsequent neurobehavior in children.

METHODS

We propose two methods, joint weighted quantile sum regression (JWQS) and meta-weighted quantile sum regression (MWQS), to estimate the effects of chemical mixtures measured across multiple time points, while providing data on their critical windows of exposure. We compare the performance of both methods using simulations. We also applied both techniques to assess second and third trimester metal mixture effects in predicting performance in the Rapid Visual Processing (RVP) task from the Cambridge Neuropsychological Test Automated Battery (CANTAB) assessed at 6-9 years in children who are part of the PROGRESS (Programming Research in Obesity, GRowth, Environment and Social Stressors) longitudinal cohort study. The metals, arsenic, cadmium (Cd), cesium, chromium, lead (Pb) and antimony (Sb) were selected based on their toxicological profile.

RESULTS

In simulations, JWQS and MWQS had over 80% accuracy in classifying exposures as either strongly or weakly contributing to an association. In real data, both JWQS and MWQS consistently found that Pb and Cd exposure jointly predicted longer latency in the RVP and that second trimester exposure better predicted the results than the third trimester. Additionally, both JWQS and MWQS highlighted the strong association Cd and Sb had with lower accuracy in the RVP and that third trimester exposure was a better predictor than second trimester exposure.

CONCLUSIONS

Our results indicate that metal mixtures effects vary across time, have distinct critical windows and that both JWQS and MWQS can determine longitudinal mixture effects including the cumulative contribution of each exposure and critical windows of effect.

A review of psychopathy and Cluster B personality traits and their neural correlates in female offenders

Although men commit more crime and are incarcerated at higher rates than women, women represent the fastest growing segment of the justice system. Empirical work suggests that psychopathy and Cluster B disorders are implicated in antisocial behavior across gender, and that neurobiological correlates of personality may inform such behavior. This review utilizes a gendered perspective to discuss psychopathy and Cluster B disorders in relation to antisocial behavior and incorporates work on neural correlates of personality disorders. Co-morbidity across these conditions may be partly explained by similar frontal deficits, reflective of disinhibition. Affective processing abnormalities appear to be characterized by distinct deficits in limbic/paralimbic regions, reflecting differential etiological underpinnings and behavioral outcomes. This review underscores the utility in examining personality pathology together with neurobiological and environmental factors. Methodological issues and clinical implications are also discussed.

The Number of Adverse Childhood Experiences Is Associated with Emotional and Behavioral Problems among Adolescents

This study aims to examine the association of adverse childhood experiences (ACE) with emotional and behavioral problems (EBP) among adolescents and the degree to which this association is stronger for more ACE. In addition, we assessed whether socioeconomic position (SEP) modifies the association of ACE with EBP. We obtained data from 341 adolescents aged 10–16 (mean age = 13.14 years; 44.0% boys), the baseline of a cohort study. We measured EBP with the strengths and difficulties questionnaire and socioeconomic position (SEP) with self-reported financial status. We used generalized linear models to analyze the association between ACE (0 vs. 1–2 vs. 3 and more) and EBP, and the modifying effect of SEP. Adolescents with 1–2 ACE (regression coefficient: 0.19; 95%-confidence interval (CI): 0.06–0.32) and with 3 ACE and over (0.35; 0.17–0.54) reported more overall problems compared with adolescents without ACE. Moreover, adolescents with 1–2 ACE (0.16; −0.01–0.32, and 0.16; 0.03–0.29) and with 3 and over ACE (0.33; 0.10–0.56, and 0.28; 0.09–0.47) reported more emotional problems and behavioral problems, respectively. The interactions of SEP with ACE were not significant. ACE are related to EBP among adolescents, with a clear dose-response association, and this association similarly holds for all SEP categories.

Neurobiological and clinical effect of metacognitive interpersonal therapy vs structured clinical model: study protocol for a randomized controlled trial

BACKGROUND

Borderline Personality Disorder (BPD) is a complex and debilitating disorder, characterized by deficits in metacognition and emotion dysregulation. The "gold standard" treatment for this disorder is psychotherapy with pharmacotherapy as an adjunctive treatment to target state symptoms. The present randomized clinical trial aims to assess the clinical and neurobiological changes following Metacognitive Interpersonal Therapy (MIT) compared with Structured Clinical Management (SCM) derived from specific recommendations in APA (American Psychiatric Association) guidelines for BPD.

METHODS

The study design is a randomized parallel controlled clinical trial and will include 80 BPD outpatients, aged 18-45 enrolled at 2 recruitment centers. Primary outcome will be the clinical change in emotion regulation capacities assessed with the Difficulties in Emotion Regulation Scale (DERS). We will also investigated the effect of psychotherapy on metacognitive abilities and several clinical features such as BPD symptomatology, general psychopathology, depression, personal functioning, and trait dimensions (anger, impulsivity, alexithymia). We will evaluate changes in brain connectivity patterns and during the view of emotional pictures. A multidimensional assessment will be performed at the baseline, at 6, 12, 18 months. We will obtain structural and functional Magnetic Resonance Images (MRIs) in MIT-Treated BPD (N = 30) and SCM-treated BPD (N = 30) at baseline and after treatment, as well as in a group of 30 healthy and unrelated volunteers that will be scanned once for comparison.

DISCUSSION

The present study could contribute to elucidate the neurobiological mechanisms underlying psychotherapy efficacy. The inclusion of a multidisciplinary study protocol will allow to study BPD considering different features that can affect the treatment response and their reciprocal relationships.

TRIAL REGISTRATION

NCT02370316 . Registered 02/24/2015.

Affective interference in borderline personality disorder: The lethality of suicidal behavior predicts functional brain profiles

BACKGROUND

Negative affective interference with executive cognition is associated with emotion dysregulation and behavioral dyscontrol in BPD, including a diathesis to suicidal and self-injurious behavior. While clinically well described, the neural basis of affective interference with central executive network function, and resulting suicidal behavior is poorly understood.

METHOD

In an fMRI study, 23 BPD suicide attempters completed an affectively modified Continuous Performance Task(X-CPT), in which targets and distractors were rendered on Negative, Positive and Neutral Ekman faces, with a Distorted image as a behavioral baseline. Responses to targets were contextualized by the affective context of the face. Lethality Rating Scale scores (LRS) were modeled as the primary regressor of interest on activation peaks, with HamD scores covaried.

RESULTS

In the Negative vs. Neutral contrast, LRS scores were inversely related to activation in the ACC, parietal precuneus, BG and OFC, with no positive relationships. Results were similar in the Negative vs Positive contrast. In the Neutral vs. Positive contrast, activations were much less extensive, with mixed positive and negative relationships. Contextualizing responses based on the effects of valence decreased participant's ability to distinguish between targets and distracters; however, no differences were observed between valence contexts. fMRI-estimated effects were not confounded by differences in behavioral sensitivity across contexts.

LIMITATIONS

In this female-only sample, possible gender differences were not addressed.

CONCLUSIONS

With negative affective interference, increased lethality of suicidal behavior in BPD predicted diminished neural activation in areas critical to executive cognitive function. Therapies diminishing affective interference may reduce risk of suicidal behavior.

A Recurrent Question: What Is Borderline?

The status of borderline personality disorder (BPD) as a diagnostic category is a matter of continuing controversy. In the United States, BPD is one of the most frequent diagnoses of psychiatric inpatients, and a similar tendency emerges in Europe. Nearly all theoretical aspects of BPD have been questioned, including its very position as a personality disorder. In this article, we trace the evolution of the borderline concept from the beginning of the 20th century to the current psychometric research. We argue that the status of BPD is fraught with conceptual difficulties, including an unrecognized semantic drift of major phenomenological terms (e.g., identity), a lack of general principles for the distinction of BPD and the major psychiatric syndromes (e.g., schizophrenia spectrum disorders), and insufficient definitions of key nosological concepts. These difficulties illustrate general problems in today's psychiatry that require consideration.

Abnormalities in functional connectivity in borderline personality disorder: Correlations with metacognition and emotion dysregulation

A few studies reported functional abnormalities at rest in borderline personality disorder (BPD), but their relationship with clinical aspect is unclear. We aimed to assess functional connectivity (FC) in BPD patients and its association with BPD clinical features. Twenty-one BPD patients and 14 healthy controls (HC) underwent a multidimensional assessment and resting-state fMRI. Independent component analysis was performed to identify three resting-state networks: default mode network (DMN), salience network (SN), and executive control network (ECN). FC differences between BPD and HC were assessed with voxel-wise two-sample t-tests. Additionally, we investigated the mean FC within each network and the relationship between connectivity measures and BPD clinical features. Patients showed significant lower mean FC in the DMN and SN, while, at the local level, a cluster of lower functional connectivity emerged in the posterior cingulate cortex of the DMN. The DMN connectivity was positively correlated with the anger-state intensity and expression, while the SN connectivity was positively correlated with metacognitive abilities and a negative correlation emerged with the interpersonal aggression. The dysfunctional connectivity within these networks might explain clinical features of BPD patients.

Repetitive Transcranial Magnetic Stimulation in the Treatment of a Difficult to Treat Condition, Borderline Personality Disorder

BACKGROUND

Borderline personality disorder (BPD) is a serious mental disorder characterized by a pervasive pattern of instability in affect regulation and interpersonal relationships, poor self-image and behavioral control, self-injurious behavior, suicidality, and other high-risk behaviors. It is also characterized by a high mortality rate by suicide.

METHODS

The published literature on repetitive transcranial magnetic stimulation (TMS), theta-burst stimulation (TBS), and deep TMS in the treatment of BPD were reviewed.

RESULTS

Four clinical studies (2 randomized trials and 2 case studies) with limited sample sizes found that TMS and TBS were safe and potentially effective in the reduction of symptoms of BPD.

CONCLUSIONS

Given the limited clinical evidence for efficacy on the basis of the results of these studies, future controlled studies involving larger samples and optimal stimulus parameters should be designed to confirm the short-term and long-term safety and efficacy of repetitive TMS and TBS in the treatment of BPD.

Fractal Analysis of BOLD Time Series in a Network Associated With Waiting Impulsivity

Fractal phenomena can be found in numerous scientific areas including neuroscience. Fractals are structures, in which the whole has the same shape as its parts. A specific structure known as pink noise (also called fractal or 1/f noise) is one key fractal manifestation, exhibits both stability and adaptability, and can be addressed via the Hurst exponent (H). FMRI studies using H on regional fMRI time courses used fractality as an important characteristic to unravel neural networks from artificial noise. In this fMRI-study, we examined 103 healthy male students at rest and while performing the 5-choice serial reaction time task. We addressed fractality in a network associated with waiting impulsivity using the adaptive fractal analysis (AFA) approach to determine H. We revealed the fractal nature of the impulsivity network. Furthermore, fractality was influenced by individual impulsivity in terms of decreasing fractality with higher impulsivity in regions of top-down control (left middle frontal gyrus) as well as reward processing (nucleus accumbens and anterior cingulate cortex). We conclude that fractality as determined via H is a promising marker to quantify deviations in network functions at an early stage and, thus, to be able to inform preventive interventions before the manifestation of a disorder.

Alterations in brain microstructure in rats that develop abnormal aggression following peripubertal stress

Exposure to early adversity is implicated in the development of aggressive behaviour later in life in some but not all individuals. The reasons for the variability in response to such experiences are not clear but may relate to pre-existing individual differences that influence their downstream effects. Applying structural magnetic resonance imaging (MRI) to a rat model of abnormal aggression induced by peripubertal stress, we examined whether individual differences in the development of an aggressive phenotype following stress exposure were underpinned by variation in the structure of aggression-associated, corticolimbic brain regions. We also assessed whether responsiveness of the hypothalamic-pituitary-adrenal axis to stress was associated with neurobehavioural outcome following adversity. A subset of the rats exposed to peripubertal stress developed an aggressive phenotype, while the remaining rats were affected in other behavioural domains, such as increased anxiety-like behaviours and reduced sociability. Peripubertal stress led to changes in tissue microstructure within prefrontal cortex, amygdala and hippocampal formation only in those individuals displaying an aggressive phenotype. Attenuated glucocorticoid response to stress during juvenility predicted the subsequent development of an aggressive phenotype in peripubertal stress-exposed rats. Our study establishes a link between peripubertal stress exposure in rats and structural deviations in brain regions linked to abnormal aggression and points towards low glucocorticoid responsiveness to stress as a potential underlying mechanism. We additionally highlight the importance of considering individual differences in behavioural response to stress when determining neurobiological correlates.

Bidirectional Regulation of Aggression in Mice by Hippocampal Alpha-7 Nicotinic Acetylcholine Receptors

Humans with 15q13.3 microdeletion syndrome (15q13.3DS) are typically hemizygous for CHRNA7, the gene coding for the α7 nicotinic acetylcholine receptor (nAChR), and manifest a variable neuropsychiatric phenotype that frequently includes persistent aggression. In mice, nAChR activation by nicotine is anti-aggressive, or 'serenic,' an effect which requires α7 nAChRs and is recapitulated by GTS-21, an α7 nAChR partial agonist. Pharmacotherapies potentiating α7 nAChR signaling have also been shown to reduce aggression in human 15q13.3DS. These findings identify the α7 nAChR as an important regulator of aggressive behavior, but the underlying neurobiological substrates remain to be determined. We therefore investigated the brain regions and potential neural circuits in which α7 nAChRs regulate aggressive behavior in male mice. As in 15q13.3DS, mice heterozygous for Chrna7 were significantly more aggressive compared to wild-type controls in the resident-intruder test. We subsequently examined the hippocampus, where α7 nAChRs are highly expressed, particularly in GABAergic interneurons. Resident-intruder interactions strongly activated granule cells in the dentate gyrus (DG). In contrast, GTS-21, which reduces aggression in mice, reduced DG granule cell activity during resident-intruder interactions. Short hairpin RNA knockdown of Chrna7 in the DG enhanced baseline aggression and eliminated the serenic effects of both nicotine and GTS-21 on attack latency. These data further implicate α7 nAChRs in regulation of aggression, and demonstrate that hippocampal α7 nAChR signaling is necessary and sufficient to limit aggression. These findings suggest that nAChR-mediated regulation of hippocampal excitatory-inhibitory balance could be a promising therapeutic intervention for aggression arising in certain forms of neuropsychiatric disease.

Abnormalities in gray matter volume in patients with borderline personality disorder and their relation to lifetime depression: A VBM study

Background

Structural imaging studies of borderline personality disorder (BPD) have found regions of reduced cortical volume, but these have varied considerably across studies. Reduced hippocampus and amygdala volume have also been a regular finding in studies using conventional volumetric measurement. How far comorbid major depression, which is common in BPD and can also affect in brain structure, influences the findings is not clear.

Methods

Seventy-six women with BPD and 76 matched controls were examined using whole-brain voxel-based morphometry (VBM). The hippocampus and amygdala were also measured, using both conventional volume measurement and VBM within a mask restricted to these two subcortical structures. Lifetime history of major depression was assessed using structured psychiatric interview.

Results

At a threshold of p = 0.05 corrected, the BPD patients showed clusters of volume reduction in the dorsolateral prefrontal cortex bilaterally and in the pregenual/subgenual medial frontal cortex. There was no evidence of volume reductions in the hippocampus or amygdala, either on conventional volumetry or using VBM masked to these regions. Instead there was evidence of right-sided enlargement of these structures. No significant structural differences were found between patients with and without lifetime major depression.

Conclusions

According to this study, BPD is characterized by a restricted pattern of cortical volume reduction involving the dorsolateral frontal cortex and the medial frontal cortex, both areas of potential relevance for the clinical features of the disorder. Previous findings concerning reduced hippocampus and amygdala volume in the disorder are not supported. Brain structural findings in BPD do not appear to be explainable on the basis of history of associated lifetime major depression.

Clinical improvement in patients with borderline personality disorder after treatment with repetitive transcranial magnetic stimulation: preliminary results

OBJECTIVE

Current treatment of borderline personality disorder (BPD) consists of psychotherapy and pharmacological interventions. However, the use of repetitive transcranial magnetic stimulation (rTMS) could be beneficial to improve some BPD symptoms. The objective of this study was to evaluate clinical improvement in patients with BPD after application of rTMS over the right or left dorsolateral prefrontal cortex (DLPFC).

METHOD

Twenty-nine patients with BPD from the National Institute of Psychiatry, Mexico, were randomized in two groups to receive 15 sessions of rTMS applied over the right (1 Hz, n=15) or left (5 Hz, n=14) DLPFC. Improvement was measured by the Clinical Global Impression Scale for BPD (CGI-BPD), Borderline Evaluation of Severity Over Time (BEST), Beck Depression Inventory (BDI), Hamilton Anxiety Rating Scale (HAM-A), and Barratt Impulsiveness Scale (BIS).

RESULTS

Intragroup comparison showed significant (p < 0.05) reductions in every psychopathologic domain of the CGI-BPD and in the total scores of all scales in both groups.

CONCLUSIONS

Both protocols produced global improvement in severity and symptoms of BPD, particularly in impulsiveness, affective instability, and anger. Further studies are warranted to explore the therapeutic effect of rTMS in BPD.

CLINICAL TRIAL REGISTRATION

NCT02273674

Sense of direction and conscientiousness as predictors of performance in the Euclidean travelling salesman problem

A salesperson wishes to visit a number of cities before returning home using the shortest possible route, whilst only visiting each city once. This optimization problem, called the Travelling Salesman Problem, is difficult to solve using exhaustive algorithms due to the exponential growth in the number of possible solutions. Interestingly, when presented in Euclidean space (ETSP), humans quickly find good solutions. Past studies, however, are in disagreement whether human solutions are impacted by the participant’s ability to process figural effects in the graph geometry. In this study, we used principal component analysis to combine two correlated [r = 0.37, p < 0.01] self-assessed personality measures, i.e., a participant’s sense of direction and a participant’s level of conscientiousness, onto a single impulsiveness/cautiousness dimension. We then showed, using simple linear regression, that this new dimension is a significant predictor [R² = 0.12, p < 0.01] of the number of edge crossings that occur in human ETSP solutions, a key metric of graph optimality. Our study provides evidence to suggest that human solutions to the ETSP are significantly affected by individual differences, including personality and cognitive traits.

Utility of the cumulative stress and mismatch hypotheses in understanding the neurobiological impacts of childhood abuse and recent stress in youth with emerging mental disorder

Childhood abuse has an enduring impact on the brain's stress system. Whether the effects of childhood abuse and adulthood stress are additive (cumulative stress hypothesis) or interactive (mismatch hypothesis) is widely disputed, however. The primary aim of this study was to test the utility of the cumulative stress and mismatch hypotheses in understanding brain and behaviour. We recruited 64 individuals (aged 14-26) from a specialised clinic for assessment and early intervention of mental health problems in young people. A T1-weighted MRI, a resting state fMRI and clinical assessment were acquired from each participant. Grey matter estimates and resting state functional connectivity (rsFC) of the hippocampus, amygdala and anterior cingulate cortex (ACC) were determined using segmentation and seed-to-voxel rsFC analyses. We explored the effects of childhood abuse and recent stress on the structure and function of the regions of interest within general linear models. Worse psychiatric symptoms were significantly related to higher levels of life time stress. Individuals with mismatched childhood and recent stress levels had reduced left hippocampal volume, reduced ACC-ventrolateral prefrontal cortex rsFC and greater ACC-hippocampus rsFC, compared to individuals with matched childhood and recent stress levels. These results show specific utility of the cumulative stress hypothesis in understanding psychiatric symptomatology and of the mismatch hypothesis in modelling hippocampal grey matter, prefrontal rsFC, and prefrontal-hippocampal rsFC. We provide novel evidence for the enduring impact of childhood abuse on stress reactivity in a clinical population, and demonstrate the distinct effects of stress in different systems. Hum Brain Mapp 38:2709-2721, 2017. © 2017 Wiley Periodicals, Inc.

A Neurobiological Model of Borderline Personality Disorder: Systematic and Integrative Review

Borderline personality disorder (BPD) is a severe mental disorder with a multifactorial etiology. The development and maintenance of BPD is sustained by diverse neurobiological factors that contribute to the disorder's complex clinical phenotype. These factors may be identified using a range of techniques to probe alterations in brain systems that underlie BPD. We systematically searched the scientific literature for empirical studies on the neurobiology of BPD, identifying 146 articles in three broad research areas: neuroendocrinology and biological specimens; structural neuroimaging; and functional neuroimaging. We consolidate the results of these studies and provide an integrative model that attempts to incorporate the heterogeneous findings. The model specifies interactions among endogenous stress hormones, neurometabolism, and brain structures and circuits involved in emotion and cognition. The role of the amygdala in BPD is expanded to consider its functions in coordinating the brain's dynamic evaluation of the relevance of emotional stimuli in the context of an individual's goals and motivations. Future directions for neurobiological research on BPD are discussed, including implications for the Research Domain Criteria framework, accelerating genetics research by incorporating endophenotypes and gene × environment interactions, and exploring novel applications of neuroscience findings to treatment research.

Brain structural anomalies in borderline and avoidant personality disorder patients and their associations with disorder-specific symptoms

BACKGROUND

Borderline personality disorder (BPD) and avoidant personality disorder (AvPD) are characterized by hyper-reactivity to negatively-perceived interpersonal cues, yet they differ in degree of affective instability. Recent work has begun to elucidate the neural (structural and functional) and cognitive-behavioral underpinnings of BPD, although some initial studies of brain structure have reached divergent conclusions. AvPD, however, has been almost unexamined in the cognitive neuroscience literature.

METHODS

In the present study we investigated group differences among 29 BPD patients, 27 AvPD patients, and 29 healthy controls (HC) in structural brain volumes using voxel-based morphometry (VBM) in five anatomically-defined regions of interest: amygdala, hippocampus, medial prefrontal cortex (MPFC), dorsolateral prefrontal cortex (DLPFC), and anterior cingulate cortex (ACC). We also examined the relationship between individual differences in brain structure and self-reported anxiety and affective instability in each group.

RESULTS

We observed reductions in MPFC and ACC volume in BPD relative to HC, with no significant difference among patient groups. No group differences in amygdala volume were found. However, BPD and AvPD patients each showed a positive relationship between right amygdala volume and state-related anxiety. By contrast, in HC there was an inverse relationship between MPFC volume and state and trait-related anxiety as well as between bilateral DLPFC volume and affective instability.

LIMITATIONS

Current sample sizes did not permit examination of gender effects upon structure-symptom correlations.

CONCLUSIONS

These results shed light on potentially protective, or compensatory, aspects of brain structure in these populations-namely, relatively reduced amygdala volume or relatively enhanced MPFC and DLPFC volume.

Neuroimagerie fonctionnelle chez l’adolescent avec un trouble de personnalité limite

De nombreuses études en neuroimagerie fonctionnelle (IRMf) menées chez les adultes présentant un trouble de personnalité limite (TPL) convergent pour identifier un patron d’activation neuronale, notamment fronto-limbique, différent de celui activé chez les adultes sans TPL lors des tâches de visualisation d’images émotionnelles. À ce jour, aucune étude en IRMf n’a été réalisée chez les adolescents avec TPL. Ce projet pilote vise à évaluer la faisabilité d’un protocole d’IRMf chez des adolescentes avec TPL et à identifier les régions neuronales d’intérêt pour les études de neuroimagerie chez cette population. Le projet porte sur six adolescentes euthymiques présentant un diagnostic de TPL (âge moyen : 15,8 ± 0,9 ans) et six adolescentes témoins sans diagnostic psychiatrique (âge moyen : 15,5 ± 1,2 ans). Après l’évaluation diagnostique incluant le Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime et le Diagnostic Interview for Borderline – Revised version, les participantes ont complété une tâche d’IRMf au cours de laquelle elles devaient regarder 20 images à valence affective positive, 20 images à valence affective négative et 20 images neutres. L’étude de faisabilité montre que les participantes ont été recrutées en 22 mois et que le protocole était bien toléré par celles-ci. Les résultats montrent que le visionnement des scènes positives et négatives a entraîné une plus grande activation de plusieurs aires limbiques ainsi que frontales, temporales et du cervelet chez le groupe TPL. Les aires limbiques et préfrontales semblent être des régions d’intérêt dans l’étude du fonctionnement neuronal chez les adolescentes avec TPL.

Network analysis of functional brain connectivity in borderline personality disorder using resting-state fMRI

Borderline personality disorder (BPD) is associated with symptoms such as affect dysregulation, impaired sense of self, and self-harm behaviors. Neuroimaging research on BPD has revealed structural and functional abnormalities in specific brain regions and connections. However, little is known about the topological organizations of brain networks in BPD. We collected resting-state functional magnetic resonance imaging (fMRI) data from 20 patients with BPD and 10 healthy controls, and constructed frequency-specific functional brain networks by correlating wavelet-filtered fMRI signals from 82 cortical and subcortical regions. We employed graph-theory based complex network analysis to investigate the topological properties of the brain networks, and employed network-based statistic to identify functional dysconnections in patients. In the 0.03–0.06 Hz frequency band, compared to controls, patients with BPD showed significantly larger measures of global network topology, including the size of largest connected graph component, clustering coefficient, small-worldness, and local efficiency, indicating increased local cliquishness of the functional brain network. Compared to controls, patients showed lower nodal centrality at several hub nodes but greater centrality at several non-hub nodes in the network. Furthermore, an interconnected subnetwork in 0.03–0.06 Hz frequency band was identified that showed significantly lower connectivity in patients. The links in the subnetwork were mainly long-distance connections between regions located at different lobes; and the mean connectivity of this subnetwork was negatively correlated with the increased global topology measures. Lastly, the key network measures showed high correlations with several clinical symptom scores, and classified BPD patients against healthy controls with high accuracy based on linear discriminant analysis. The abnormal topological properties and connectivity found in this study may add new knowledge to the current understanding of functional brain networks in BPD. However, due to limitation of small sample sizes, the results of the current study should be viewed as exploratory and need to be validated on large samples in future works.

•

We analyzed the topology and connectivity of functional brain networks in BPD.

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Patients with BPD showed altered small-world properties and network efficiency.

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Patients with BPD showed altered nodal centrality at specific brain regions.

•

An interconnected subnetwork showed significantly lower connectivity in BPD.

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Key network measures were correlated with clinical symptom scores.

Morphometric analysis of amygdla and hippocampus shape in impulsively aggressive and healthy control subjects

BACKGROUND

Impulsive aggressive behavior is thought to be facilitated by activation of the limbic brain, particularly the amygdala and hippocampus., Functional imaging studies suggest abnormalities in limbic brain activity during emotional information processing in impulsively aggressive subjects with Intermittent Explosive Disorder (IED). It is not known if IED is associated with altered amygdala and hippocampus volume and shape.

METHODS

We examined the volume and shape of the amygdala-hippocampal complex, using morphometric analysis of high resolution structural 3T MR scans in healthy control (HC: n = 73) subjects without history of Axis I or II psychiatric conditions and in subjects with IED (n = 67).

RESULTS

While no volume differences were observed between HC and IED subjects, a significant level of morphometric deformation, suggestive of cell loss, in both amygdala and hippocampal structures was observed bilaterally in IED subjects. Analysis of a canonical variable that used the first 10 eigenvectors from both sides of the brain revealed that these morphometric deformations in the IED subjects were not due the presence of confounding variables or to comorbidities among IED subjects.

CONCLUSIONS

These data reveal that IED is associated with a significant loss of neurons in both the amygdala and hippocampus. These changes may play a role in the functional abnormalities observed in previous fMRI studies and in the pathophysiology of impulsive aggressive behavior.

Self-reported impulsivity is negatively correlated with amygdalar volumes in cocaine dependence

Although impulsivity has been associated with cocaine dependence and other addictive behaviors, the biological factors underlying impulsivity have yet to be precisely determined. This study aimed to examine relationships between impulsivity and volumes of the amygdala and hippocampus in cocaine-dependent and healthy comparison individuals. The Barratt Impulsiveness Scale (BIS-11) was used to assess impulsivity. FreeSurfer was used to assess amygdalar and hippocampal volumes from high-resolution structural magnetic resonance images. Relative to healthy comparison subjects, cocaine-dependent individuals scored higher on all three subscales of BIS-11 but did not differ from healthy comparison subjects in amygdalar or hippocampal volumes. Cocaine-dependent individuals showed significant negative correlations between amygdalar volumes and scores on the BIS-11 Attentional subscale, and this relationship differed significantly from the non-significant relationship in healthy comparison subjects. As individual differences in amygdalar structure may contribute to the high impulsivity observed in cocaine-dependent individuals, the findings suggest that future studies should assess the extent to which therapies that target impulsivity in cocaine dependence may operate through the amygdala or alter its structure or function.

Affective context interferes with brain responses during cognitive processing in borderline personality disorder: fMRI evidence

Emotion dysregulation in borderline personality disorder (BPD) is associated with loss of cognitive control in the face of intense negative emotion. Negative emotional context may interfere with cognitive processing through the dysmodulation of brain regions involved in regulation of emotion, impulse control, executive function and memory. Structural and metabolic brain abnormalities have been reported in these regions in BPD. Using novel fMRI protocols, we investigated the neural basis of negative affective interference with cognitive processing targeting these regions. Attention-driven Go No-Go and X-CPT (continuous performance test) protocols, using positive, negative and neutral Ekman faces, targeted the orbital frontal cortex (OFC) and the anterior cingulate cortex (ACC), respectively. A stimulus-driven Episodic Memory task, using images from the International Affective Pictures System, targeted the hippocampus (HIP). Participants comprised 23 women with BPD, who were compared with 15 healthy controls. When Negative>Positive faces were compared in the Go No-Go task, BPD subjects had hyper-activation relative to controls in areas reflecting task-relevant processing: the superior parietal/precuneus and the basal ganglia. Decreased activation was also noted in the OFC, and increased activation in the amygdala (AMY). In the X-CPT, BPD subjects again showed hyper-activation in task-relevant areas: the superior parietal/precuneus and the ACC. In the stimulus-driven Episodic Memory task, BPD subjects had decreased activation relative to controls in the HIP, ACC, superior parietal/precuneus, and dorsal prefrontal cortex (dPFC) (for encoding), and the ACC, dPFC, and HIP for retrieval of Negative>Positive pictures, reflecting impairment of task-relevant functions. Negative affective interference with cognitive processing in BPD differs from that in healthy controls and is associated with functional abnormalities in brain networks reported to have structural or metabolic abnormalities. Task demands exert a differential effect on the cognitive response to negative emotion in BPD compared with control subjects.

Beating the brain about abuse: Empirical and meta-analytic studies of the association between maltreatment and hippocampal volume across childhood and adolescence

We present new empirical data and meta-analytic evidence for the association of childhood maltreatment with reduced hippocampal volume. In Study 1, we examined the effects of maltreatment experiences reported during the Adult Attachment Interview on hippocampal volume in female twin pairs. We found that reduced hippocampal volume was related to childhood maltreatment. In addition, individuals who reported having experienced maltreatment at older ages had larger reductions in hippocampal volume compared to individuals who reported maltreatment in early childhood. In Study 2, we present the results of a meta-analysis of 49 studies (including 2,720 participants) examining hippocampal volume in relation to experiences of child maltreatment, and test the moderating role of the timing of the maltreatment, the severity of maltreatment, and the time after exposure to maltreatment. The results of the meta-analysis confirmed that experiences of childhood maltreatment are associated with a reduction in hippocampal volume and that the effects of maltreatment are more pronounced when the maltreatment occurs in middle childhood compared to early childhood or adolescence.