A neural network model of Borderline Personality Disorder

The humanness of artificial non-normative personalities

Technoscientific ambitions for perfecting human-like machines, by advancing state-of-the-art neuromorphic architectures and cognitive computing, may end in ironic regret without pondering the humanness of fallible artificial non-normative personalities. Self-organizing artificial personalities individualize machine performance and identity through fuzzy conscientiousness, emotionality, extraversion/introversion, and other traits, rendering insights into technology-assisted human evolution, robot ethology/pedagogy, and best practices against unwanted autonomous machine behavior.

The role of central and medial amygdala in normal and abnormal aggression: A review of classical approaches

The involvement of the amygdala in aggression is supported by overwhelming evidence. Frequently, however, the amygdala is studied as a whole, despite its complex internal organization. To reveal the role of various subdivisions, here we review the involvement of the central and medial amygdala in male rivalry aggression, maternal aggression, predatory aggression, and models of abnormal aggression where violent behavior is associated with increased or decreased arousal. We conclude that: (1) rivalry aggression is controlled by the medial amygdala; (2) predatory aggression is controlled by the central amygdala; (3) hypoarousal-associated violent aggression recruits both nuclei, (4) a specific upregulation of the medial amygdala was observed in hyperarousal-driven aggression. These patterns of amygdala activation were used to build four alternative models of the aggression circuitry, each being specific to particular forms of aggression. The separate study of the roles of amygdala subdivisions may not only improve our understanding of aggressive behavior, but also the differential control of aggression and violent behaviors of various types, including those associated with various psychopathologies.

Epigenetic and Neural Circuitry Landscape of Psychotherapeutic Interventions

The science behind psychotherapy has garnered considerable interest, as objective measures are being developed to map the patient's subjective change over the course of treatment. Prenatal and early life influences have a lasting impact on how genes are expressed and the manner in which neural circuits are consolidated. Transgenerationally transmitted epigenetic markers as well as templates of enhanced thought flexibility versus evasion can be passed down from parent to child. This influences gene expression/repression (impacting neuroplasticity) and kindling of neurocircuitry which can perpetuate maladaptive cognitive processing seen in a number of psychiatric conditions. Importantly, genetic factors and the compounding effects of early life adversity do not inexorably lead to certain fated outcomes. The concepts of vulnerability and resilience are becoming more integrated into the framework of "differential susceptibility," speaking to how corrective environmental factors may promote epigenetic change and reconfigure neural templates, allowing for symptomatic improvement. Psychotherapy is one such factor, and this review will focus on our current knowledge of its epigenetic and neurocircuitry impact.

Inconsistency and social decision making in patients with Borderline Personality Disorder

Inconsistent social behavior is a core psychopathological feature of borderline personality disorder. The goal of the present study was to examine inconsistency in social decision-making using simple economic social experiments. We investigated the decisions of 17 female patients with BPD, 24 patients with major depressive disorder (MDD), and 36 healthy controls in three single shot economic experiments measuring trust, cooperation, and punishment. BPD severity was assessed using the Zanarini Rating Scale for BPD. Investments across identical one-shot trust and punishment games were significantly more inconsistent in BPD patients than in controls. Such inconsistencies were only found in the social risk conditions of the trust and punishment conditions but not in the non-social control conditions. MDD patients did not show such inconsistencies. Furthermore, social support was negatively correlated with inconsistent decision-making in the trust and punishment game, which underscores the clinical relevance of this finding.

Effects of adverse early-life events on aggression and anti-social behaviours in animals and humans

We review the impact of early adversities on the development of violence and antisocial behaviour in humans, and present three aetiological animal models of escalated rodent aggression, each disentangling the consequences of one particular adverse early-life factor. A review of the human data, as well as those obtained with the animal models of repeated maternal separation, post-weaning social isolation and peripubertal stress, clearly shows that adverse developmental conditions strongly affect aggressive behaviour displayed in adulthood, the emotional responses to social challenges and the neuronal mechanisms activated by conflict. Although similarities between models are evident, important differences were also noted, demonstrating that the behavioural, emotional and neuronal consequences of early adversities are to a large extent dependent on aetiological factors. These findings support recent theories on human aggression, which suggest that particular developmental trajectories lead to specific forms of aggressive behaviour and brain dysfunctions. However, dissecting the roles of particular aetiological factors in humans is difficult because these occur in various combinations; in addition, the neuroscientific tools employed in humans still lack the depth of analysis of those used in animal research. We suggest that the analytical approach of the rodent models presented here may be successfully used to complement human findings and to develop integrative models of the complex relationship between early adversity, brain development and aggressive behaviour.

The spectrum of borderline personality disorder: a neurophysiological view

Borderline Personality Disorder (BPD) has been defined as a personality disorder in all editions of DSM since 1980; namely, DSM III through V. The criteria are a mixture of symptoms and traits; the etiology, a heterogeneous array of genetic, constitutional, and environmental factors. Until recently the diagnosis relied on clinical descriptions. In the last two decades, neurophysiological data, including MRI and fMRI, have established correlates in various brain regions, particularly those involving the frontal lobes and various limbic structures, that show promise of providing a more substantial basis for diagnosis-relying primarily on (internal) brain changes, rather than on (external) clinical observation. Some of the changes in BPD consist of decreased volume in the orbitofrontal and dorsolateral prefrontal cortices and smaller volume in both the amygdala and hippocampus, though with heightened reactivity in the amygdala. Similar abnormalities have been noted in bipolar disorders (BDs) and in ADHD, both of which often accompany BPD and share certain clinical features. Persons with strong genetic predisposition to BDs can develop BPD even in the absence of adverse environmental factors; those with extreme adverse environmental factors (chiefly, early sexual molestation) can develop BPD in the absence of bipolar vulnerability. In some BPD patients, both sets of factors are present. As ideal treatment depends on careful analysis of these factors, neurophysiological testing may permit both more rational, brain-based diagnostic decisions and more appropriate therapeutic strategies.

Emotional modulation of motor response inhibition in women with borderline personality disorder: an fMRI study

BACKGROUND

Both emotion regulation and impulsivity are core aspects of borderline personality disorder (BPD) pathology. Although both problems may be combined specifically in BPD, few studies to date have investigated the emotional modulation of impulsivity in BPD.

METHODS

Women with BPD and matched healthy controls performed go/no-go tasks after induction of anger, joy or a neutral mood by vocally presented short stories. Dependent variables were the behavioural results and functional magnetic resonance imaging data.

RESULTS

We included 17 women with BPD and 18 controls in our study. No behavioural group differences were found. However, patients with BPD showed stronger activation of the left amygdala and weaker activation of the subgenual anterior cingulate during anger induction than controls. Inhibition in the go/no-go task after anger induction increased activity in the left inferior frontal cortex in controls, but not in women with BPD, who, in turn, showed increased activation in the subthalamic nucleus.

LIMITATIONS

Findings cannot be generalized to men, and 4 patients were taking antidepressant medication (selective serotonin reuptake inhibitors). In addition, no patient control group was investigated, thus we do not know whether findings are specific to BPD compared with other disorders.

CONCLUSION

Our findings are consistent with the view that a disturbed amygdala-prefrontal network in patients with BPD is compensated by a subcortical loop involving the subthalamic nucleus, leading to normal behavioural inhibition in these patients.

Medial prefrontal dysfunction and prolonged amygdala response during instructed fear processing in borderline personality disorder

OBJECTIVES

Affective dysregulation is a clinical hallmark of borderline personality disorder (BPD). This study used an instructed fear task combined with functional MRI (fMRI) and skin conductance response (SCR) to test hypotheses about mechanisms of disturbed fronto-limbic neural circuitry underlying dysfunctional emotional processing in BPD.

METHODS

Female BPD patients and matched control subjects were exposed to two visual stimuli during fMRI scanning and SCR recording. Subjects were instructed shortly before scanning that one stimulus (Threat) potentially represents an aversive event whereas another stimulus (Safe) represents safety. The aversive event (electrodermal stimulation) itself was only experienced before this instruction and never occurred during fMRI scanning.

RESULTS

Both groups showed stronger SCR to Threat compared to Safe indicating differential fear response which habituated over time. BPD compared to control subjects did not show fMRI signal decrease of amygdala activity or relative ventromedial prefrontal cortex (vmPFC) activity increase over time. Moreover, BPD patients showed increased connectivity of the amygdala with vmPFC but decreased connectivity of subgenual ACC with dorsal ACC compared to control subjects.

CONCLUSIONS

Prolonged amygdala response and a functional disconnection between ventral and dorsal mPFC regions may be part of the neural mechanisms underlying emotional dysregulation in BPD patients.

Psychiatric comorbidity in refractory focal epilepsy: a study of 490 patients

We studied the prevalence and associated factors of psychiatric comorbidities in 490 patients with refractory focal epilepsy. Of these, 198 (40.4%) patients had psychiatric comorbidity. An Axis I diagnosis was made in 154 patients (31.4%) and an Axis II diagnosis (personality disorder) in another 44 (8.97%) patients. After logistic regression, positive family history of psychiatric comorbidities (O.R.=1.98; 95% CI=1.10-3.58; p=0.023), the presence of Axis II psychiatric comorbidities (O.R.=3.25; 95% CI=1.70-6.22; p<0.0001), and the epileptogenic zone located in mesial temporal lobe structures (O.R.=1.94; 95% CI=1.25-3.03; p=0.003) remained associated with Axis I psychiatric comorbidities. We concluded that a combination of clinical variables and selected structural abnormalities of the central nervous system contributes to the development of psychiatric comorbidities in patients with focal epilepsy.

The plight of personality disorders in the DSM-5

This article provides a brief history of the development of the Diagnostic and Statistical Manual of Mental Disorders published by the American Psychiatric Association, and how it relates to the proposed fifth edition to be published in 2013. Of particular emphasis is Axis II and how this axis is likely to be restructured. The reconceptualization of the nosology for personality disorders has been controversial since the publication of the DSM-III-R (Wilson, 1993). In both the clinical and academic communities, ongoing debate about diagnostic classification of personality disorders has been common. One recurrent theme among the deliberations on diagnosis and personality disorder focuses on the question of whether distinct (categorical) diagnoses exist or whether diagnoses are dimensionally related to each other in some empirically determined way. The proposed changes for Axis II in the DSM-5 are likely to bridge the gap between these two arguments by revamping the overall criteria and discarding the three currently used diagnostic clusters. The resulting nosology proposes six personality disorders with common factors in Criteria A and Criteria B. However, a major concern and a continuing problem not likely to be resolved in this edition is the symptom resemblance of borderline personality disorder and bipolar disorder. This article suggests some ways the revised DSM might affect mental health nursing practice.

Amygdalar volume in borderline personality disorder with and without comorbid post-traumatic stress disorder: a meta-analysis

INTRODUCTION

Four studies have found a smaller amygdalar volume in patients with borderline personality disorder (BPD) relative to controls, whereas four other studies have found similar amygdalar volume in BPD patients relative to controls. This study aims to compare amygdalar volumes of BPD patients with controls, and also to compare BPD patients with and without post-traumatic stress disorder (PTSD) with controls in order to determine whether PTSD can explain the heterogeneity of findings.

METHOD

Systematic review and meta-analysis of magnetic resonance imaging studies that measured amygdalar volumes in BPD patients and healthy controls.

FINDINGS

A significant reduction of amygdalar volumes in BPD patients was confirmed (p < .001). However, data from the studies that discriminated BPD patients with and without PTSD indicated that amygdalar volumes were significantly smaller in BPD patients without PTSD relative to controls (left: p = .02; right: p = .05), but not in BPD patients with PTSD relative to controls (left: p = .08; right: p = .20).

CONCLUSION

This meta-analysis suggests that amygdalar volumes are reduced in patients with BPD. This pattern is confirmed in BPD patients without PTSD, but not in BPD patients with PTSD, raising the possibility that reduced amygdalar volume in BPD patients cannot be explained by comorbid PTSD.

Borderline personality disorder and bipolar affective disorder. Spectra or spectre? A review

OBJECTIVE

Bipolar affective disorder and borderline personality disorder have long been considered to have significant similarities and comorbidity. This review endeavours to clarify the similarities and differences between these disorders, with an effort to determine whether they reflect different forms of the same illness or separate illness clusters.

METHOD

The published literature relating to bipolar affective disorders, borderline personality disorders, and related areas of knowledge was reviewed using searches of several electronic databases (AMED, CINHAL, Embase, Ovid, ProQuest, MEDLINE, Web of Science, ScienceDirect) and published texts. These findings were combined with the personal clinical experience of the author, and information gathered from colleagues, to create a review of this topic.

RESULTS

Bipolar affective disorders and borderline personality disorders differ with respect to sense of self, disruption of relationships, family history of bipolar disorders, the benefits of medications, the extent of cognitive deficits, the form of affective dysregulation and mood cycling, the incidence of suicide and suicide attempts, the form of psychotic episodes, the incidence of early sexual abuse but not early trauma in general, the loss of brain substance, alterations in cortical activity, glucocorticoid receptor sensitivity, and mitochondrial dysfunction. They are similar with respect to non-specific features of affective dysregulation, the incidence of atypical depressive features, the incidence of self-mutilation, the incidence of transporter polymorphisms, possible genetic linkages, overall reduction in limbic modulation, reduction in the size of hippocampi and amygdala, and the incidence of sleep disruption.

CONCLUSIONS

This review concludes that bipolar affective disorders and borderline personality disorder are separate disorders, but have significant elements in common.