Borderline Personality Disorder

Etiology

The current hypothesis is that BPD is caused by an interaction between genetic factors and adverse childhood experiences affecting brain development via neuropeptides and hormones.[7] The relative importance of these factors is unclear.[8]

Genetic studies propose a hereditary component of personality disorders, including BPD. The estimated heritability of BPD is approximately 40%.[8] In a Swedish population, the familial association of BPD was highest for monozygotic twins, then dizygotic twins, then full siblings, then half-siblings.[9] A caveat is that twin studies may overestimate the genetic effect on personality disorders, as twins are generally raised in a shared family environment.[10] Meta-analyses have not supported the proposed association of BPD with the serotonin transporter gene, the tryptophan hydroxylase 1 gene, or the serotonin 1B receptor gene, and there are no identified single-nucleotide variants associated with BPD.[8][11] 

Multiple factors within social and family domains contribute to increased risk for BPD, although none are disorder-specific. Indices of broader social risk include low socioeconomic status, family adversity, maternal psychopathology, parental substance use, low warmth/harsh punishment, child abuse, neglect, and low cognitive function. Studies also show links between temperament factors and later BPD.[12][13]

BPD must be distinguished from personality traits arising from other medical conditions. Conditions associated with personality changes include head trauma, cerebrovascular accident, CNS neoplasms, epilepsy, neurosyphilis, multiple sclerosis, endocrine disorders, heavy metal poisoning, and HIV-associated neurocognitive disorders.[14] 

Psychoanalytic approaches to BPD focus on unconscious processes, early childhood experiences, and the influence of internal conflicts.[15] Psychoanalyst Wilhelm Reich introduced the concept of "character armor," referring to defense mechanisms individuals develop to alleviate cognitive conflict arising from internal impulses and interpersonal anxiety.[16] Defense mechanisms associated with BPD are projection, splitting, and acting out, which are related to insecure attachment.[17][18] The term "splitting" refers to the defense mechanism in which the patient cannot form a realistic view of another person. At any given time, the other person is viewed as entirely good or entirely bad. This inability to view others as having both positive and negative attributes impairs personal relationships. Otto Kernberg theorized that lack of integration in the early maternal relationship led to BPD.[19] Kernberg hypothesized that the infant experiences the maternal figure in a dichotomous framework: the loving and nurturing mother who provides for the child and the punishing, hateful mother who deprives the child. This contradiction causes intense anxiety and, if not integrated into a more moderate unitary concept, leads to splitting. Kernberg also points out that BPD is complex and warns of reductionist shortcuts in searching for etiology.[19]

Personality is a unique pattern of behaviors that an individual adopts in response to constantly changing internal and external stimuli. It is a complex summation of biological, psychological, social, and developmental factors. Each personality is unique, even among those people grouped and labeled with a personality disorder. This uniqueness is broadly described as temperament, a heritable and innate psychobiological characteristic. Cloninger describes the 4 dimensions of temperament as harm avoidance, novelty seeking, reward dependence, and persistence, which are independently heritable.[20] Harm avoidance involves a bias towards inhibiting behavior that would result in punishment or non-reward.[21] Individuals with BPD may have higher harm avoidance and fearful, anxiety-prone traits.[22][23] Novelty seeking is an inherent desire to initiate novel activities likely to produce a reward signal. Individuals with BPD tend to have a high amount of novelty-seeking behaviors.[22][23] Temperament is further shaped through life experiences such as trauma and socioeconomic conditions; these are adaptive etiological factors in personality development.[24][25] 

Epidemiology

Nationwide epidemiologic studies estimate the prevalence of BPD in the general population between 0.7% and 2.7%, with symptoms usually manifesting in early adulthood.[26][27][28] In primary care, the prevalence is 6%, and the rate is 11% to 12% in outpatient psychiatric clinics and 22% for psychiatric inpatients.[29] Although women have a slightly higher rate of BPD than men (3% versus 2.4%), in outpatient psychiatric settings, there are higher rates of BPD in women (78% versus 28%).[30][31][32]

Pathophysiology

Current neurobiological models of BPD link findings across neuroendocrinology, structural neuroimaging, and functional neuroimaging. Specific genes may be involved with disruptions in the hypothalamic-pituitary-adrenal axis consistent with stress-related changes and chronic elevation of cortisol, affecting emotional regulation and impulse control.[33] Neuroimaging studies have identified differences in the amygdala, hippocampus, and medial temporal lobes in patients with BPD, which may also be related to self-reported childhood trauma.

Top-down control abnormalities are seen in BPD, showing that cortical activity to moderate the amygdala (and other limbic areas) is impaired. Instead, behavior is driven from the bottom-up, meaning that amygdala activation is unmoderated by higher-level cortical functions.[34] Studies also suggest that patients with BPD may misattribute negative emotions (fear, anger, disgust) to neutral faces more than control patients despite having the perception of happy and upset faces equivalent to those groups.[35] On neuropsychological testing, patients with BPD have impaired cognitive flexibility and increased impulsivity. No correlation was found between BPD symptom severity and cognitive functions.[36][37]

History and Physical

The presentation of BPD is variable. Obtaining a thorough psychiatric history, medical history, social history, developmental history, and history of family dynamics is essential for diagnosis. The features of BPD may start emerging in adolescence, and impulsive and dangerous behaviors may increase through early adulthood. The presence of affective instability identifies most patients with BPD, who describe fluctuating moods throughout the day depending on circumstances and interactions with others. This mood instability is different than a depressive episode or manic episode, both of which have more consistent mood symptoms.[38] Individuals with BPD display wide emotional lability, including the potential to react strongly and become angry, violent, or suicidal.

Inquiring about the patient's relationships with family, friends, and romantic partners can help diagnose patients with suspected BPD. Splitting is common, viewing others as "all good" or "all bad" from moment to moment. Individuals with BPD can become dependent on others but also have dramatic shifts in their feelings when feeling abandoned or disregarded.[39] Men with BPD are more impaired, impulsive, and aggressive than women with BPD and may be at higher risk of dying by suicide.[40] People with BPD describe chronic feelings of "emptiness" related to hopelessness, loneliness, and isolation.[41] Maladaptive coping is inherent in the diagnosis of BPD. It can present as substance use, impulsive spending, high-risk sexual behavior, binge eating, reckless driving, self-harm, or self-sabotaging behaviors. Body modification by excessive piercings, tattoos, or scarification can represent identity diffusion and low self-concept clarity and may be connected to BPD.[42] 

Self-harming behavior can be either nonsuicidal self-harm or suicidal behavior (with the intent to die). Nonsuicidal self-harm can be expressed by deliberate cutting among women and hitting one's own body in men. Suicide methods include hanging oneself, shooting oneself, jumping off a tall structure, substance overdose, and refusing fluids and food. Nonsuicidal self-harm and suicidal behavior are interrelated, and self-harming behavior is a risk factor for future suicide. Any self-harming behavior should be carefully assessed for intent to die.[43][44] Suicidal behaviors tend to remit over time, but suicidality may continue when BPD symptoms are untreated or severe or if the patient is poorly functioning. Another risk factor for suicide is comorbid major depressive disorder.[45] 

The mental status examination is crucial in assessing individuals for BPD. The specific elements and findings of the examination can vary depending on each case of BPD. Assessment of patients should include the following:

• Appearance: Individuals with BPD may have excessive tattoos, piercings, or scarification. The patient should be assessed for scars from cutting.[42]                                                                                                
• Behavior: Splitting behavior may be present, and the clinician should be sensitive to this dynamic. Patients with BPD may be angry, antagonistic, or violent.                                                                                  
• Affect: Patients with BPD may present with constricted, dysphoric, or angry affect.                                               
• Thought content: Assess for thoughts of self-harm, suicidality, or thoughts of harming others. Transient psychosis may be present.                                                                                                                              
• Thought process: Individuals with BPD are usually clear and coherent but may dissociate at times.                                     
• Cognition: Individuals with BPD are usually cognitively intact and oriented to person, place, and date.                                      
• Insight: Typically, individuals with BPD have a poor understanding of how their behaviors are related to their feelings, dysregulated emotions, and interpersonal difficulties.                                                                        
• Judgment and impulse control: Poor judgment and poor impulse control are common in patients with BPD. 

Evaluation

Diagnosis of BPD is based on the longitudinal observation of a patient's behaviors to assess functioning over time. The symptoms of a personality disorder may overlap with symptoms observed during acute psychiatric conditions such as mood disorders. If possible, personality disorders should be diagnosed when other psychiatric conditions are quiescent.[46] BPD can also significantly contribute to the exacerbation of another psychiatric illness and lead to hospitalization.[47] 

Clinicians often develop a psychological reaction to patients with BPD, which is known as "countertransference." This occurs due to the nature of the encounters, as patients may be difficult, aggressive, self-harming, or suicidal.[48] Clinicians must recognize signs of countertransference, which may negatively affect patient care.[49] When clinicians feel frustrated with patients who may be suffering from a personality disorder, it is helpful to use those feelings as an evaluation tool to guide diagnosis and treatment.[50][51]

Evidence-based assessment of BPD can include a self-report inventory, such as the 10-item, true-false McLean Screening Instrument for BPD. A score of 7 or more yields both good sensitivity and specificity for diagnosing BPD. The Zanarini rating scale is another common tool used to screen for BPD.[52]

Psychological testing can help diagnose personality disorders but is not generally needed for a diagnosis of BPD when a sufficient history is available. The Minnesota Multiphasic Personality Inventory-2 and the Rorschach Perceptual Thinking Index may be used to verify the presence of a personality disorder.[53][54][55] Individuals must meet the diagnostic criteria specified in the DSM-5-T to formally diagnose BPDR. The diagnosis requires a thorough evaluation that considers multiple sources of information, including personal history, collateral information, and a mental status examination. A comprehensive assessment allows clinicians to assess the individual's symptoms, functioning, and overall presentation to see if diagnostic criteria are met.

DSM-5-TR Categorical Criteria for BPD

A pervasive pattern of instability of interpersonal relationships, self-image, and affects, and marked impulsivity beginning by early adulthood and present in a variety of contexts, as indicated by 5 or more of the following:

1. Frantic efforts to avoid real or imagined abandonment                                                                                         
2. A pattern of unstable and intense interpersonal relationships characterized by alternating between extremes of idealization and devaluation                                                                                                         
3. Identity disturbance: markedly and persistently unstable self-image or sense of self                                                 
4. Impulsivity in at least 2 areas that are potentially self-damaging, for example, spending, substance abuse, reckless driving, sex, or binge eating                                                                                                                 
5. Recurrent suicidal behavior, gestures, or threats, or self-mutilating behavior                                                                                                         
6. Affective instability due to a marked reactivity of mood, for example, intense episodic dysphoria, anxiety, or irritability, usually lasting a few hours and rarely more than a few days                                                                                                                                        
7. Chronic feelings of emptiness                                                                                                                                
8. Inappropriate, intense anger or difficulty controlling anger, for example, frequent displays of temper, constant anger, or recurrent physical fights                                                                                                                                                          
9. Transient, stress-related paranoid ideation or severe dissociative symptoms                                      

DSM-5-TR Alternative Dimensional Model for Diagnosing BPD

To preserve continuity with the categorical diagnostic model, the DSM-5-TR includes a hybrid dimensional-categorical model that defines personality disorders in terms of personality functioning and pathological traits. This approach acknowledges that individuals do not usually present with symptoms of just 1 personality disorder.

The proposed diagnostic criteria for BPD include 2 sets of characteristic difficulties. First, there is moderate or greater impairment in personality functioning manifested by problems in 2 or more areas: identity, self-direction, empathy, or intimacy. Second, 4 or more of the following personality traits must be present: emotional lability, anxiousness, separation insecurity, depressivity, impulsivity, risk-taking, or hostility. At least 1 must be impulsivity, risk-taking, or hostility.  

Treatment / Management

The first-line treatment for BPD is psychotherapy.[56][57] BPD-tailored therapies are effective for patients with BPD compared to treatment as usual. In clinical trials, psychotherapy improved psychosocial functioning, reduced the severity of BPD symptoms, and may reduce self-harm and depression. The efficacy of psychotherapy for adolescents is not known due to the lack of high-quality studies.[7](A1)

Mentalization-based treatment (MBT) is a complex attachment-based psychological therapy program that helps patients with BPD regulate emotions by increasing their mentalizing capacity and reflective functioning. Patients can then understand and recognize their feelings and the feelings they evoke in others. MBT combines individual therapy and group therapy.[7]

Dialectical behavioral therapy (DBT) is a highly structured psychological therapy that combines mindfulness practices with concrete interpersonal and emotion regulation skills based on cognitive behavioral therapy. DBT aims to change behavior and enable the patient to tolerate distressing feelings by skill-building in emotion regulation, mindfulness, and interpersonal behavior. DBT combines individual therapy, group therapy, and weekly team consultations for the therapists.[7]

Transference-focused psychotherapy (TFP) uses the patient-therapist relationship to develop the patient's awareness of problematic interpersonal dynamics. The therapist uses clarification, confrontation, and transference interpretation within the relationship between the patient and the therapist.[7]

The goal of schema therapy (ST) is the development of a healthy adult. ST addresses 4 dysfunctional life schemas characteristic of BPD: the abandoned/abused child, the angry/impulsive child, the detached protector, and the punitive parent. Cognitive-behavioral, psychodynamic, attachment, and emotion-focused approaches characterize ST.[7]

There is no evidence that pharmacotherapy is efficacious for BPD core symptoms, yet contrary to guidelines, up to 96% of patients with BPD receive at least 1 psychotropic medication, and polypharmacy is common.[58] No medications are FDA-approved for the treatment of BPD.[56] Medications such as serotonin reuptake inhibitors (SRIs), mood stabilizers, and antipsychotic medications show limited effectiveness in trials aimed at the control of transient symptoms of anxiety, sleep disturbance, depression, or agitation.[59] Pharmacotherapy is only recommended for the treatment of comorbid disorders such as severe depression or anxiety, transient psychotic symptoms, severe agitation, or aggressive behavior.[7]

Polypharmacy can be associated with iatrogenic harm and contribute to functional impairment. Consider reducing patients' high-risk polypharmacy regimens when determining the risks and benefits of a treatment regimen.[60](B3)

Self-injurious behavior, boundary issues, suicidality, and substance use present challenges in the treatment of patients with BPD.

Patients with BPD do not typically require hospitalization; however, inpatient care may be necessary in certain situations as follows:

• Overt suicidal ideation with imminent risk of high lethality behavior                                                                                 
• Intense negative thoughts, agitation, or transient psychosis                                                                                              
• Rapid escalation in the severity of self-harm                                                                                                        
• Exacerbation of comorbid psychiatric disorders or substance use disorders

Differential Diagnosis

BPD often co-occurs with depressive or bipolar disorders, which should be diagnosed if the criteria for those disorders are met. Exacerbations of BPD can mimic mood disorders, so the diagnosis of BPD should only be made based on documented long-standing patterns of behavior. 

Both separation anxiety and BPD are characterized by fear of abandonment, but problems with impulsivity, identity, and interpersonal functioning are needed to diagnose BPD.

Personality disorders have overlapping features and can be confused with BPD. It is essential to distinguish BPD by its characteristic features. If an individual meets the criteria for more than 1 personality disorder, the other personality disorders can be diagnosed.

Dissociative identity disorder is characterized by 2 or more personality states that are each distinct and with an enduring pattern of behavior. In BPD, there are problems with identity and self-image, but these are transient, unstable, and fluctuate. 

Persistent substance use can lead to symptoms that mimic BPD.

BPD must be distinguished from personality traits arising from another medical condition. Conditions associated with personality changes include head trauma, cerebrovascular accident, CNS neoplasms, epilepsy, neurosyphilis, multiple sclerosis, endocrine disorders, heavy metal poisoning, and HIV-associated neurocognitive disorders.[14] 

Pertinent Studies and Ongoing Trials

There are significant limitations to existing models for describing personality disorders, including BPD. The "cluster" system is commonly used due to its implementation in the DSM. Similar patterns of behavior are classified into syndromes known as personality disorders; however, the uniqueness of each person remains a problem for the diagnosis and research into each specific personality disorder as patterns overlap and diverge.[6] 

Experts in personality disorders suggest switching to a dimensional model of personality. Dimensional models generally describe temperament, utilization of defense mechanisms, and pathological personality traits to diagnose personality disorders.[61] 

The DSM-5-TR Alternative Dimensional Model for Diagnosing BPD preserves continuity with the categorical diagnostic model with a hybrid dimensional-categorical model that defines personality disorders in terms of personality functioning and pathological traits. This approach also acknowledges that individuals do not usually present with symptoms of just 1 personality disorder.

The paradigm will likely shift further towards a dimensional model as research informs evolving clinical guidelines about diagnosis and treatment. In addition, high-quality head-to-head trials of the major forms of psychotherapy and studies of the nature of mechanisms of change are needed.

Prognosis

Patients with BPD have a fair prognosis, and studies demonstrate that BPD psychopathology improves more than generally expected but that psychosocial functioning often remains impaired. Systematic meta-analysis with 5- to 15-year follow-up periods showed mean remission rates of 60%.[62]

Despite high rates of remission and low rates of relapse, patients with BPD have severe and persistent impairment in functional and social recovery. This is consistent with the theory that with stable supports and avoidance of interpersonal stressors, patients with BPD remit clinically. Patients with persistent BPD were more likely to have had inpatient treatment and had more comorbid borderline psychopathology.[63][64][65]

Complications

Patients with BPD have a higher rate of suicide (5.9%) than patients with other personality disorders (1.4%). In 1 study, more than 75% of patients with BPD had suicide attempts.[7][66] Other complications of BPD include comorbid medical conditions such as obesity, diabetes, gastrointestinal disease, cardiovascular disease, hypertension, chronic pain, and sexually transmitted diseases. There is a strong association between BPD and all other personality disorders, mood disorders, eating disorders, posttraumatic stress disorder, and substance use disorders. People with BPD have a poorer life expectancy than others and struggle to negotiate the health care system.[7][67][68]