The neurobiology of personality disorders: implications for psychoanalysis

Avoidant Personality Disorder Symptoms and Cardiovascular Reactivity to Psychological Stress Tasks With Increasing Cognitive Demands

Abstract. This study aimed to investigate whether and how avoidant personality disorder symptoms are related to cardiovascular reactivity to stress tasks with different levels of cognitive demands. The revised Chinese edition of the avoidant personality disorder subscale of Personality Diagnosed Questionnaire-4+ (PDQ-4+) was administered to 222 undergraduate students randomly assigned to psychological stress tasks (i.e., mental arithmetic tasks) with low, moderate, or high cognitive demands (manipulated by task difficulty), during which their physiological data were continuously collected. Results showed that avoidant personality disorder symptoms and cognitive demands of tasks interactively predicted systolic blood pressure (SBP) and diastolic blood pressure (DBP) reactivity. In specific, avoidant personality disorder symptoms were not associated with SBP reactivity under the low- and moderate-demand conditions and DBP reactivity under the low-demand condition but were associated with blunted SBP reactivity under the high-demand condition and blunted DBP reactivity under the moderate- and high-demand conditions. These findings indicate that the association between avoidant personality disorder symptoms and cardiovascular reactivity to psychological stress is contingent on the cognitive demands of tasks, which have potential implications for physical health.

Personality Disturbances as Emergent Phenomena Reflective of Underlying Neurobehavioral Systems: Beyond Dimensional Measurement, Phenotypic Trait Descriptors, and Factor Analysis

The conceptualization of personality pathology, or personality disturbance, is now at a substantive crossroads. Some researchers (and clinicians) prefer a focus on the domains of personality pathology that are well-described and captured in traditional categorical diagnostic approaches that, in some instances, abut normal personality constructs. Other workers argue to move the study of personality disorder (PD) closer to personality science seeking continuous connections between PD and established dimensions of healthy-range, normal personality. Most of the latter efforts revolve around correlational and factor analytic study of phenotypic expressions of PD features and normal personality dimensions. It is notable, however, that both visions of the PD/personality interface are essentially unlinked to an understanding of shared neurobiological underpinnings (i.e., neurotransmitter-influenced neurobehavioral systems) of both personality disturbance and normal personality<A51_FootRef>1</A51_FootRef>. Here, we present a nontechnical, conceptual overview of our approach to this problem, advancing a neurobehavioral approach that seeks to anchor both normal personality and personality disturbance within a matrix of brain-based neurobiological systems, incorporating genetic, epigenetic, and environmental inputs. In this brief paper, we seek only to provide a necessarily cursory introduction to how we conceptualize this area and illustrate, in broad outline, our effort to characterize both personality and personality disturbance anchored in neurobehavioral systems. Our approach, which we began developing in the middle 1990s, can be juxtaposed with the more recently proposed DSM-5 Alternative Model of Personality Disorders as well as the well-established five-factor approach to PD.

Personality patterns of people with medically refractory epilepsy - Does the epileptogenic zone matter?

OBJECTIVES

The aims of this study were to determine the rate of dysfunctional personality patterns before and after epilepsy surgery, their types, and the importance of the epileptogenic zone in a sample of people with refractory epilepsy.

METHODS

We conducted an ambispective observational study, including refractory epilepsy surgery candidates. Demographic, psychiatric, and neurological data were recorded. Evaluation of personality was made using the Millon Clinical Multiaxial Inventory-II (MCMI-II). Presurgical predictors of personality patterns were determined using a linear regression model. The proportion of patients with dysfunctional personality patterns, before and after surgery, was compared using the Mcnemar's test. Then a generalized estimating equation model was performed to include predictors of changes in this rate.

RESULTS

One hundred and ninety-nine participants were included. Seventy percent had a dysfunctional personality pattern before surgery. After surgery, this percentage dropped to 58%. The difference was statistically significant after adjusting for potential confounders (p = 0.013). The most common types were Cluster C personality patterns. Temporal epileptogenic zone was a significant predictor of higher scores of the Avoidant (Coef. 11.8; Confidence Interval (CI) -0.59 23.7; p = 0.051) and Compulsive (Coef. 9.55; CI 2.48 16.6; p = 0.008) personality patterns and lower scores of Histrionic (Coef. -11.4; CI -21.2 -1.55; p = 0.024) and Antisocial (Coef. -8.4; CI -15.6 -1.25; p = 0.022) personality patterns, compared to extratemporal epileptogenic zone.

CONCLUSION

People with refractory epilepsy have high rates of dysfunctional personality patterns. These patterns differ according to the epileptogenic zone.

[The concept of schizoidia in psychiatry : From schizoidia to schizotypy and cluster A personality disorders]

From a perspective of conceptual evolution schizoidia was initially considered to describe features both of the premorbid personality of schizophrenic patients and of the personalities of non-psychotic family members (Bleuler, Kahlbaum, Kraepelin). On a psychopatholocial level a close link to the complex basic symptom of autism was stressed. From the very beginnings of modern psychiatry schizoidia was discussed within a conceptual frame of schizophrenia spectrum disorders (Kretschmer, Hoch, Polatin). Approaches to operationalize these conceptual works laid the basis for the cluster A personalities in DSM-III. Due to the prominent concept of schizotypy (Kety, Rado, Meehl) three split up diagnostic categories of schizotypal, schizoid and paranoid personality disorders resulted. Cluster A personality disorders are frequent in community-based epidemiological studies. Health-care seeking behaviour due to primary personality-related problems, however, seems to be less paramount compared to cluster B and C personality disorders. Many family- and twin-based genetic studies convincingly stress a close link between schizotypal personality disorder and schizophrenia. This link is less pronounced for paranoid personality disorder, and even vanishingly low for schizoid personality disorder. From a perspective of schizophrenia spectrum disorders a vast amount of data from molecular genetic, neurobiological, neuropsychological and psychosocial research has impressingly confirmed this link for schizotypal personality disorder. Major research deficits, however, have to be noticed for paranoid and schizoid personality disorder.

Repetitive TMS on Left Cerebellum Affects Impulsivity in Borderline Personality Disorder: A Pilot Study

The borderline personality disorder (BPD) is characterized by a severe pattern of instability in emotional regulation, interpersonal relationships, identity and impulse control. These functions are related to the prefrontal cortex (PFC), and since PFC shows a rich anatomical connectivity with the cerebellum, the functionality of the cerebellar-PFC axis may impact on BPD. In this study, we investigated the potential involvement of cerebello-thalamo-cortical connections in impulsive reactions through a pre/post stimulation design. BPD patients (n = 8) and healthy controls (HC; n = 9) performed an Affective Go/No-Go task (AGN) assessing information processing biases for positive and negative stimuli before and after repetitive transcranial magnetic stimulation (rTMS; 1 Hz/10 min, 80% resting motor threshold (RMT) over the left lateral cerebellum. The AGN task consisted of four blocks requiring associative capacities of increasing complexity. BPD patients performed significantly worse than the HC, especially when cognitive demands were high (third and fourth block), but their performance approached that of HC after rTMS (rTMS was almost ineffective in HC). The more evident effect of rTMS in complex associative tasks might have occurred since the cerebellum is deeply involved in integration and coordination of different stimuli. We hypothesize that in BPD patients, cerebello-thalamo-cortical communication is altered, resulting in emotional dysregulation and disturbed impulse control. The rTMS over the left cerebellum might have interfered with existing functional connections exerting a facilitating effect on PFC control.

Longitudinal and Sex Measurement Invariance of the Affective Neuroscience Personality Scales

The Affective Neuroscience Personality Scales (ANPS) is a personality instrument based on six evolutionary-related brain systems that are at the foundation of human emotions and behaviors: SEEKING, CARING, PLAYFULNESS, FEAR, ANGER, and SADNESS. We sought to assess for the short and long versions of the ANPS: (a) the longitudinal measurement invariance and long-term (4-year) stability and (b) the sex measurement invariance. Using data from a Canadian cohort ( N = 518), we used single-group confirmatory factor analysis to assess longitudinal invariance and multiple-group confirmatory factor analysis to assess sex invariance, according to a five-step approach evaluating five invariance levels (configural, metric, scalar, residual, and complete). Results supported full longitudinal invariance for both versions for all invariance levels. Partial residual invariance was supported for sex invariance. The long-term stability of both versions was good to excellent. Implications for personality assessment and ANPS development are discussed.

Aberrant DNA Methylation of rDNA and PRIMA1 in Borderline Personality Disorder

Borderline personality disorder (BPD) is a serious psychic disease with a high risk for suicide. DNA methylation is a hallmark for aberrant epigenetic regulation and could be involved in the etiology of BPD. Previously, it has been reported that increased DNA methylation of neuropsychiatric genes is found in the blood of patients with BPD compared to healthy controls. Here, we analyzed DNA methylation patterns of the ribosomal RNA gene (rDNA promoter region and 5′-external transcribed spacer/5′ETS) and the promoter of the proline rich membrane anchor 1 gene (PRIMA1) in peripheral blood samples of 24 female patients (mean age (33 ± 11) years) diagnosed with DSM-IV BPD and in 11 female controls (mean age (32 ± 7) years). A significant aberrant methylation of rDNA and PRIMA1 was revealed for BPD patients using pyrosequencing. For the promoter of PRIMA1, the average methylation of six CpG sites was 1.6-fold higher in BPD patients compared to controls. In contrast, the methylation levels of the rDNA promoter region and the 5′ETS were significantly lower (0.9-fold) in patients with BPD compared to controls. Thus, for nine CpGs located in the rDNA promoter region and for four CpGs at the 5′ETS decreased methylation was found in peripheral blood of patients compared to controls. Our results suggest that aberrant methylation of rDNA and PRIMA1 is associated with the pathogenesis of BPD.

Understanding recovery in the context of lived experience of personality disorders: a collaborative, qualitative research study

BACKGROUND

Concepts of recovery increasingly inform the development and delivery of mental health services internationally. In the UK recent policy advocates the application of recovery concepts to the treatment of personality disorders. However diagnosis and understanding of personality disorders remains contested, challenging any assumption that mainstream recovery thinking can be directly translated into personality disorders services.

METHODS

In a qualitative interview-based study understandings of recovery were explored in extended, in-depth interviews with six people purposively sampled from a specialist personality disorders' service in the UK. An interpretive, collaborative approach to research was adopted in which university-, clinical- and service user (consumer) researchers were jointly involved in carrying out interviews and analysing interview data.

RESULTS

Findings suggested that recovery cannot be conceptualised separately from an understanding of the lived experience of personality disorders. This experience was characterised by a complexity of ambiguous, interrelating and conflicting feelings, thoughts and actions as individuals tried to cope with tensions between internally and externally experienced worlds. Our analysis was suggestive of a process of recovering or, for some, discovering a sense of self that can safely coexist in both worlds.

CONCLUSIONS

We conclude that key facilitators of recovery - positive personal relationships and wider social interaction - are also where the core vulnerabilities of individuals with lived experience of personaility disorders can lie. There is a role for personality disorders services in providing a safe space in which to develop positive relationships. Through discursive practice within the research team understandings of recovery were co-produced that responded to the lived experience of personality disorders and were of applied relevance to practitioners.

Protein kinase C is essential for kainate-induced anxiety-related behavior and glutamatergic synapse upregulation in prelimbic cortex

AIM

Anxiety is one of common mood disorders, in which the deficit of serotonergic and GABAergic synaptic functions in the amygdala and prefrontal cortex is believed to be involved. The pathological changes at the glutamatergic synapses and neurons in these brain regions as well as their underlying mechanisms remain elusive, which we aim to investigate.

METHODS

An agonist of kainate-type glutamate receptors, kainic acid, was applied to induce anxiety-related behaviors. The morphology and functions of glutamatergic synapses in the prelimbic region of mouse prefrontal cortex were analyzed using cellular imaging and electrophysiology.

RESULTS

After kainate-induced anxiety is onset, the signal transmission at the glutamatergic synapses is upregulated, and the dendritic spine heads are enlarged. In terms of the molecular mechanisms, the upregulated synaptic plasticity is associated with the expression of more protein kinase C (PKC) in the dendritic spines. Chelerythrine, a PKC inhibitor, reverses kainate-induced anxiety and anxiety-related glutamatergic synapse upregulation.

CONCLUSION

The activation of glutamatergic kainate-type receptors leads to anxiety-related behaviors and glutamatergic synapse upregulation through protein kinase C in the prelimbic region of the mouse prefrontal cortex.

Neuroimaging for psychotherapy research: current trends

OBJECTIVE

This article reviews neuroimaging studies that inform psychotherapy research. An introduction to neuroimaging methods is provided as background for the increasingly sophisticated breadth of methods and findings appearing in psychotherapy research.

METHOD

We compiled and assessed a comprehensive list of neuroimaging studies of psychotherapy outcome, along with selected examples of other types of studies that also are relevant to psychotherapy research. We emphasized magnetic resonance imaging (MRI) since it is the dominant neuroimaging modality in psychological research.

RESULTS

We summarize findings from neuroimaging studies of psychotherapy outcome, including treatment for depression, obsessive compulsive disorder (OCD), and schizophrenia.

CONCLUSIONS

The increasing use of neuroimaging methods in the study of psychotherapy continues to refine our understanding of both outcome and process. We suggest possible directions for future neuroimaging studies in psychotherapy research.

Personality disorders, attachment and psychodynamic psychotherapy

While attachment has been a fruitful and critical concept in understanding enduring individual templates for interpersonal relationships, it does not have a well-understood relationship to personality disorders, where impairment of interpersonal functioning is paramount. Despite the recognition that attachment disturbances do not simply reflect nonoptimal caretaking environments, the relationship of underlying temperamental factors to these environmental insults has not been fully explored. In this paper we provide an alternate model for the role of neurobiological temperamental factors, including brain circuitry and neuropeptide modulation, in mediating social cognition and the internalization and maintenance of attachment patterns. The implications of these altered attachment patterns on personality disorders and their neurobiological and environmental roots for psychoanalytically based treatment models designed to ameliorate difficulties in interpersonal functioning through the medium of increased access to mature forms of mentalization is discussed.

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.

Mentalizing-based treatment with adolescents and families

In this article, the process of mentalizing, its components, and role in self-regulation and attachment are reviewed. An examination is presented of the neurodevelopmental changes affecting the adolescent's capacity to mentalize and the role of such compromised mentalizing in the adolescent's vulnerability to adaptive breakdown and psychopathology, in general, and to emerging personality disorders, in particular. The principles, objectives, and core features of mentalizing-based treatment and its application to adolescents and families are discussed.

A new look at borderline personality disorder and related disorders: hyper-reactivity in the limbic system and lower centers

Borderline Personality Disorder (BPD) has been often described recently as a condition characterized by emotional dysregulation. Several other conditions share this attribute; namely, Bipolar Disorder (BD), Attention-Deficit/Hyperactivity Disorder (ADHD), Intermittent Explosive Disorder (IED), and Major Depressive Disorder (MDD). The dysregulation is not always in the same direction: BPD, BD, ADHD, and IED, for example, show over-reactivity or "hyperactivity" of emotional responses, whereas patients with MDD show emotional sluggishness and underactivity. At the clinical/descriptive level the "over-reactive" conditions appear separate and distinct. BPD constitutes a large domain within the psychopathological arena, appearing to contain within it a variety of etiologically diverse subtypes. Among the latter is a type of BPD linked closely with Bipolar Disorder; family studies of either condition show an overrepresentation of both: BPD patients with bipolar relatives; Bipolar patients with BPD relatives. A significant percentage of children with ADHD go on to develop either BPD or BD as they approach adulthood. If one shifts the spotlight to neurophysiology, as captured by MRI studies, however, it emerges that an important subtype of BPD, and also BD, ADHD, and IED-share common features of abnormalities and peculiarities in the limbic system and in the cortex, especially the prefrontal cortex. Deeper subcortical regions such as the periaqueductal gray may also be implicated in strong emotional reactions. The diversity of clinical "over-reactive" conditions appear to harken back to a kind of unity at the brain-change level. There are therapeutic implications here, such as the advisability of mood stabilizers in many cases of BPD, not just for Bipolar Disorder.

Toward a definition of affective instability

Affective instability is a psychophysiological symptom observed in some psychopathologies. It is a complex construct that encompasses (1) primary emotions, or affects, and secondary emotions, with each category having its own characteristics, amplitude, and duration, (2) rapid shifting from neutral or valenced affect to intense affect, and (3) dysfunctional modulation of emotions. Affective instability is often confused with mood lability, as in bipolar disorders, as well as with other terms. To clarify the concept, we searched databases for the term affective instability and read related articles on the topic. In this article we situate the term within the current affective nomenclature and human emotional experience, explore its psychophysiological features, and place it within the context of psychopathology. We explain why the term can potentially be confused with mood pathology and then define affective instability as an inherited temperamental trait modulated by developmental experience.

mGluR₁,5 activation improves network asynchrony and GABAergic synapse attenuation in the amygdala: implication for anxiety-like behavior in DBA/2 mice

Anxiety is a prevalent psychological disorder, in which the atypical expression of certain genes and the abnormality of amygdala are involved. Intermediate processes between genetic defects and anxiety, pathophysiological characteristics of neural network, remain unclear. Using behavioral task, two-photon cellular imaging and electrophysiology, we studied the characteristics of neural networks in basolateral amygdala and the influences of metabotropic glutamate receptor (mGluR) on their dynamics in DBA/2 mice showing anxiety-related genetic defects. Amygdala neurons in DBA/2 high anxiety mice express asynchronous activity and diverse excitability, and their GABAergic synapses demonstrate weak transmission, compared to those in low anxiety FVB/N mice. mGluR_1,5 activation improves the anxiety-like behaviors of DBA/2 mice, synchronizes the activity of amygdala neurons and strengthens the transmission of GABAergic synapses. The activity asynchrony of amygdala neurons and the weakness of GABA synaptic transmission are associated with anxiety-like behavior.

Aggressive behaviour in schizophrenic patients after abrupt treatment discontinuation

OBJECTIVE

This retrospective study examined the demographic, clinical and pharmacological factors associated with aggressive behaviour after abrupt discontinuation of medication in schizophrenic patients.

METHOD

The study reports on a survey of 402 schizophrenic patients, who had abruptly discontinued their medication and had been involuntarily hospitalized to Psychiatric Hospital of Attika. The survey utilized the Discontinuation-Emergent Signs and Symptoms Checklist (DESS) to assess the signs and symptoms that patients exhibited (Rosenbaum et al., Biol Psychiatry 1998;44:77), as well the Aggression Scale (Delgado-Escueta et al., New England J Med 1981;305:711) to estimate the aggressive behaviour. Demographic and clinical variables as well as variables related to pharmacological treatment have been also investigated.

RESULTS

Analyses revealed that the presence of aggressive behaviour after abrupt drug discontinuation was associated positively with previous history of aggression, male gender , abrupt discontinuation of anticholinergics, delusions, nervousness or anxiety, elevated mood, irritability and negatively with negative symptoms. These predictors can correctly classify 76.3% of patients with aggressive behaviour and 64.0% of patients without aggressive behaviour.

CONCLUSION

These findings suggest that abrupt discontinuation of medication in schizophrenic patients may lead to aggressive behaviour, being connected at least in the acute phase with particular demographic, clinical and pharmacological parameters.

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

BACKGROUND

Borderline Personality Disorder (BPD) patients are characterized by increased levels of aggressivity and reduction of impulse control, which are behavioural dimensions mainly sustained by hippocampus and dorsolateral prefrontal cortex (DLPFC). In this study we aimed at investigating whether hippocampus and DLPFC anatomy may sustain impulsive and aggressive behaviours in BPD.

METHODS

Fifteen DSM-IV BPD patients (11 females, 4 males) and fifteen 1:1 matched healthy controls (11 females, 4 males) were studied with a 1.5T magnetic resonance imaging (MRI) and underwent a psychopathological assessment in order to measure the severity of aggressive and impulsive traits.

RESULTS

Right hippocampal volumes were significantly reduced in BPD patients compared to healthy subjects (p=0.027), particularly in those with a history of childhood abuse (p=0.01). Moreover, in patients but not in controls, right hippocampal volumes significantly inversely correlated with aggressiveness and DLPFC grey matter volumes significantly inversely associated with impulsiveness (p<0.05).

CONCLUSIONS

Our results provide evidence that hippocampus and DLPFC play a separate and unique role in sustaining the control of impulse and aggressive behaviours in BPD patients.

On the formation of figurative representations: An integrative psychoanalytic-neurobiological framework

This article approaches the process of symbolization with a formalized framework that aims to integrate psychoanalytic and neurobiological findings. The authors propose a framework consisting of unconscious and conscious areas. Each of the areas provides networks for storing memories. Psychoanalytically, mental networks contain memories either unconscious or conscious. Neurobiologically, there are subunits of neuronal networks crucial for the storage and recall of memories. Communication between these networks is based on selective memory recall in order to form, for example, figurative representations.

Current status of the scientific study of the personality disorders: an overview of epidemiological, longitudinal, experimental psychopathology, and neurobehavioral perspectives

Research on the nature and development of personality disorders has grown immensely over the past thirty years. A selective summary overview is given of the current status of the scientific study of the personality disorders from several perspectives, including the epidemiological, longitudinal, experimental psychopathology, and neurobehavioral perspectives. From this research, we now know that approximately 10 percent of the general population suffer from a diagnosable personality disorder. Moreover, contrary to nearly a century of theory and clinical pedagogy, modern longitudinal studies clearly suggest that personality disorders decrease in severity over time. The mechanisms by which this change occurs are not understood at present, though it is not likely that change in underlying normal personality systems drives the change in personality disorder. The methods of the experimental psychopathology laboratory, including neuroimaging approaches, are being brought to bear on the nature of personality disorders in efforts to relate neurobiological and neurocognitive functions to personality disorder symptomatology. A model that links personality disorder feature development to underlying, interacting brain-based neurobehavioral systems is reviewed in brief. Current issues and findings illustrative of these developments are given using borderline personality disorder as an exemplar. Finally, areas of intersection between psychoanalytic treatment approaches and the growing science of personality disorder are highlighted.

The relationship of DSM-IV personality disorders to nicotine dependence-results from a national survey

This study examined the prevalence of nicotine dependence (ND) and its associations with DSM-IV personality disorders (PDs) among current smokers (n=7078), controlling for sociodemographic characteristics and comorbid Axis I and II disorders. Data were derived from a nationally representative sample of the U.S. population. Although all PDs were significantly associated with ND when sociodemographic factors were controlled, only schizotypal, borderline, narcissistic and obsessive-compulsive PDs were associated with ND after adding controls for Axis I and other Axis II disorders. These associations remained significant after controlling for degree of smoking exposure. The results suggest that both shared and PD-specific pathogenetic factors underlie these PD-ND associations. Implications are also discussed in terms of the relationship between personality features of schizotypal, borderline, narcissistic and obsessive-compulsive PDs and the self-medication hypothesis and the role of neurotransmission.

An attachment perspective on borderline personality disorder: advances in gene-environment considerations

Accumulating evidence points to severe relationship dysfunction as the core epigenetic expression of borderline personality disorder (BPD). In adulthood, BPD is typified by disorganization within and across interpersonal domains of functioning. When interacting with their infants, mothers with BPD show marked withdrawal and frightening or frightened behavior, leading to disorganized infant-mother attachments. Linked to both infant disorganization and BPD is a maternal state of mind typified by unresolved mourning regarding past loss or trauma. Early risk factors for BPD in adulthood include maternal withdrawal in infancy and separation of 1 month or more from mother in the first 5 years of life. Likely contributing biological factors include genes linked to dopamine, serotonin, the hypothalamic-pituitary-adrenal axis, and neuropeptides. The complex gene-environment picture emerging confers risk or protection against BPD pathology in ways consistent with infants varying biological sensitivity to context. This line of research may refine early risk assessment and preventive mental health services.

The interpersonal dimension of borderline personality disorder: toward a neuropeptide model

Borderline personality disorder is characterized by affective instability, impulsivity, identity diffusion, and interpersonal dysfunction. Perceived rejection and loss often serve as triggers to impulsive, suicidal, and self-injurious behavior, affective reactivity, and angry outbursts, suggesting that the attachment and affiliative system may be implicated in the disorder. Neuropeptides, including the opioids, oxytocin, and vasopressin, serve a crucial role in the regulation of affiliative behaviors and thus may be altered in borderline personality disorder. While clinical data are limited, the authors propose alternative neuropeptide models of borderline personality disorder and review relevant preclinical research supporting the role of altered neuropeptide function in this disorder in the hope of stimulating more basic research and the development of new treatment approaches.