Narcissistic Personality Disorder

Etiology

There are very limited investigations and understandings of the etiology of NPD. A few behavioral genetic studies have demonstrated that NPD (and other cluster B personality disorders) is highly heritable.[9][10] Medical conditions are often associated with personality disorders or personality changes, specifically including those with pathology that may damage neurons. This includes but is not limited to head trauma, cerebrovascular diseases, cerebral tumors, epilepsy, Huntington disease, multiple sclerosis, endocrine disorders, heavy metal poisoning, neurosyphilis, and AIDS.[11]

Psychoanalytic factors contribute to the development of personality traits and disorders; however, narcissistic qualities are not implicity pathological, as narcissistic traits are a normal part of human development. Narcissism manifests around age 8, increases in adolescence, and decreases in adulthood.[12] Still, individuals with a high degree of narcissism early in life tend to maintain a high degree of narcissism in later years.[13] 

Psychoanalyst Wilhelm Reich described "character armor" as defense mechanisms that develop with personality types to relieve cognitive conflict from internal impulses and interpersonal anxiety (eg, those with narcissistic tendencies have fantasy, projection defense, and splitting mechanisms).[14] Negative developmental experiences such as being rejected as a child and ego fragility during early childhood may contribute to the development of NPD in adulthood.[15] In contrast, excessive praise in childhood, including the belief that a child may have extraordinary abilities, may also develop into a lifetime need for constant praise and admiration.[16] 

Personality is a complex summation of biological, psychological, social, and developmental factors; therefore, each personality is unique, even amongst those labeled with a personality disorder. Personality is a pattern of behaviors that an individual adapts uniquely to address constantly changing internal and external stimuli. This is more broadly described as temperament, which is a heritable and innate psychobiological characteristic.[17][18] However, temperament is further shaped through epigenetic mechanisms, namely through life experiences such as trauma and socioeconomic conditions, referred to as adaptive etiological factors in personality development.[19][20] Temperament traits include harm avoidance, novelty seeking, reward dependence, and persistence.

Harm Avoidance 

Harm avoidance involves a bias towards inhibiting behavior that would result in punishment or nonreward.[21] Individuals with NPD have relatively low harm avoidance; instead, they may act in general disregard for the consequences of their actions or view the potential gain from risky behavior as far outweighing the gamble of any potential harm that may result. Further, individuals with NPD are generally outgoing and have few social inhibitions.

Novelty Seeking 

Novelty seeking describes an inherent desire to initiate novel activities likely to produce a reward signal.[22] Individuals with NPD have moderate-to-high novelty-seeking behaviors. They tend to be hot-tempered and social; some are thrill-seeking.

Reward Dependence 

Reward dependence describes the amount of desire to cater to behaviors in response to social reward cues.[23] Individuals with NPD have high reward dependence, to the point of demanding praise when completing tasks or forming new relationships. Individuals with NPD try to be social but for the sake of receiving praise or being seen in association with others of high status, which provides them with internal reward and validation.

Persistence 

Persistence describes the ability to maintain behaviors despite frustration, fatigue, and limited reinforcement. Interestingly, individuals with NPD are quite persistent, with an extreme desire to seek out a reward. They will persist in certain behaviors; however, this is generally one of their most major maladaptive traits, particularly when combined with their tendency for low harm avoidance. These individuals strive for higher accomplishments and social status worthy of praise.[23]

Epidemiology

There are significant challenges in diagnosing NPD, as these individuals may not often present for psychiatric evaluation. High-quality and multipopulation measures are lacking. Prevalence rates from United States community samples have been estimated from 0% to 6.2% of the population.[24] Interviews of 34,653 adults who participated in the Wave 2 National Epidemiologic Survey on Alcohol and Related Conditions revealed a lifetime prevalence for NPD of 6.2% (7.7% for men, 4.8% for women).[2] 

Pathophysiology

There are limited investigations for neuroimaging in persons diagnosed with NPD. A voxel-based morphometry (VBM) study conducted in Germany with a small sample size showed gray matter decreased volumes in the prefrontal and insular regions.[25] Another voxel-based morphometry and diffuse tensor imaging study showed grey matter reduction in the right prefrontal and anterior cingulate cortices.[26] Notably, these brain regions are associated with empathy, compassion, cognition, and emotional regulation processing. 

There is also a limited understanding of the psychological pathology in NPD. There are 2 proposed subtypes of NP: grandiose NPD and vulnerable NPD.[27] The grandiose subtype includes overt grandiosity, aggression, a profound lack of empathy, exploitation, and boldness. The vulnerable subtype presents with hypersensitivity and defensiveness and may be overlooked; these individuals may be more susceptible to affective disorders due to a fragile ego.[28]

History and Physical

The presentation of NPD is highly variable. Persons with NPD generally speak from a place of self-importance and may demand or expect special treatment. In the clinical setting, amongst physicians, managers, and other high-ranking professionals, a patient with NPD may present as friendly while simultaneously presenting as cruel and bitter towards other staff not viewed as high-ranking. They may try to brag about their credentials and friends they view as having high status (ie, name-dropping). They are generally unable to handle criticism from peers or staff and frequently become enraged.[29][30] 

The clinical history is likely to reveal tumultuous relationships. Often, these individuals become increasingly isolated as they grow older due to others having difficulty maintaining their friendships with those who suffer from severe NPD. Additionally, legal charges are often present in the clinical history, as individuals with NPD have difficulty following rules (or believing rules apply to them).[30] Descriptions of empathy are limited when discussing failed relationships. Although many individuals with NPD deny feelings of depression or any signs of perceived weakness, they often suffer symptoms of depression due to an underlying fragile ego perpetuated by socio-occupational impairment from their maladaptive behaviors.[31]

The mental status examination is completed in psychiatric evaluations and varies amongst each case of NPD. Still, the following areas should be carefully considered in the psychiatric evaluation of NPD.[32] 

• Appearance: The clinician should note the patient's general grooming and fashion choices. Clothing, accessories, hairstyles, or tattoos that are provoking may suggest NPD, as there is a sense of grandiosity and attention-seeking behavior characteristic of the disorder. 
• Behavior: The clinician should monitor for disinhibited behaviors, grandiose postures, smirking, and scoffing. The context of the patient's cooperation should be paid particular attention to, as it may vary greatly depending on who the individual interacts with (depending on their perceived status). 
• Speech: NPD may present with an increased amount of speech due to feelings of needing to prove oneself or brag about achievements and friendships, but there are no expected concerns with speech initiation, volume, or vocabulary.
• Affect: Affect is highly variable but may fluctuate greatly depending on the conversation topic, particularly if the patient with NPD feels challenged or threatened by the interviewer. More lability is expected than usual, with more frequent irritability. 
• Thought content: It is essential to assess for delusions in patients with NPD. The level of grandiose thought may border between nondelusional grandiose thoughts and delusional (psychotic) grandiose thoughts. Although this distinction does not impact the treatment plan, it does help the clinician assess the severity of NPD.
• Thought process: The thought process in NPD is generally concrete, with grandiosity being unchallengeable. Still, individuals with NPD have the capability for linear and logical thought, often used to achieve their initial accomplishments (higher education, careers, relationships of status).  
• Cognition: General cognition and orientation are not expected to be impaired in NPD but should be evaluated to rule out other psychiatric conditions.
• Insight: NPD is an egosyntonic disorder; therefore, a patient's understanding of their NPD is generally poor. Accepting self-deficit is usually not congruent with NPD.
• Judgment: The severity of NPD will impact a patient's judgment. This can often be assessed by inquiring of the patient's legal and relationship histories.
• Impulse control: The underlying temperament of NPD is classic for high reward dependence and low harm avoidance behaviors, which generally results in poor impulse control. This can also be assessed by inquiring about past legal and relationship history. 

Evaluation

Diagnosis of a personality disorder benefits from longitudinal observation of a patient's behaviors over various circumstances to give a broader understanding of long-term functioning. Because many personality disorder features overlap with symptoms during another acute psychiatric condition, personality disorders should generally be diagnosed when no acute psychiatric process is concurrently occurring.[33] However, this is not always possible or required, as in the cases of an underlying personality disorder contributing significantly to hospitalizations or relapse of another psychiatric condition (ie, major depressive episode).[34] Still, it may take several visits with a patient to finally establish a firm diagnosis of NPD. 

Patients with cluster B personality disorders often display transference, which is a projection of their prior conflicts onto the clinician. Clinicians often develop counter-transference, which is when the clinician projects unresolved conflicts onto the patient. This frequently occurs due to the nature of the patient encounters for individuals who have personality disorders, as they may be aggressive, unreasonable to logic, or rude.[35]

Clinicians must recognize signs of counter-transference when they occur to remove any treatment bias that may impact the clinical care of a patient with NPD.[36] Sublimation is a psychological defense mechanism that helps individuals transform unwanted or unhelpful impulses into less harmful or helpful ones. When clinicians begin to feel frustrated with patients who may be suffering from a personality disorder, it is useful (when possible) to sublimate the negative feelings of counter-transference and use those feelings instead as an evaluation tool to guide the differential diagnosis towards a personality disorder, which may ultimately direct the treatment plan. [37]

Various structured interviews and inventories have been developed to assist in evaluating NPD. Otto Kernberg's structured clinical interview, created in 1981, has continued to undergo revisions and restructuring as a structured clinical interview for personality disorders. The current version is a semistructured diagnostic interview with questions about personality organization, defenses, object relations, and coping skills. This interview focuses on interpersonal relationships. The Personality Institute at the Weill Cornell Institute copyrights the current version. The interview is based on psychodynamic principles and is expected to be used by persons with previous training in psychoanalytical work.[38] 

Other instruments may measure the severity of NPD, such as the five-factor narcissism inventory that looks at the 5 aspects of general personality. There are about 148 questions on the measure.[39] Another measure that may be useful is the Narcissistic Personality Inventory.[40] For formal diagnosis, the conglomerate of information provided by personal history, collateral information, mental status examination, and psychometric tools, individuals must meet the DSM-5-TR diagnostic criteria for NPD.

NPD DSM-5-TR Criteria 

In interpersonal settings, there is a pervasive pattern of grandiosity, need for admiration, and lack of empathy. This pattern of behaviors onsets in early adulthood and persists through various contexts. Clinical features include at least 5 of the following:

• Having a grandiose sense of self-importance, such as exaggerating achievements and talents, expecting to be recognized as superior even without commensurate achievements
• Preoccupation with fantasies of success, power, beauty, and idealization
• Belief in being "special" and that they can only be understood by or associated with other high-status people (or institutions)
• Demanding excessive admiration
• Sense of entitlement
• Exploitation behaviors
• Lack of empathy
• Envy towards others or belief that others are envious of them
• Arrogant, haughty behaviors and attitudes [1]

Treatment / Management

Individuals with NPD may not recognize their illness as it is generally egosyntonic. The presentation is commonly at the behest of a first-degree relative or friend. Typically, this occurs after maladaptive behaviors have created stress on another rather than internal distress from the individual with NPD. Therefore, assessing the treatment goals in each specific NPD case is essential. As NPD is unlikely to remit with or without treatment, the focus of therapy may be aimed at reducing interpersonal conflict and stabilizing psychosocial functioning.[41] 

There is minimal evidence that pharmacotherapy helps treat NPD unless there is a comorbid psychiatric illness. There are no FDA-approved medications for the treatment of NPD[42]. Psychotherapy is likely the most preferable treatment for NPD despite there also being limited evidence for its efficacy. Transfered-focused therapy may have more success than other types of therapies.[43][44] Case management can help assist patients with NPD in maintaining income, shelter, and connection to medical and mental health services, as well as assistance with other basic needs.(B3)

Differential Diagnosis

NPD should be considered when a long-term pattern of rigid behaviors is observed over various internal and external stimuli. Many behaviors observed in NPD may overlap with symptoms of other psychiatric illnesses, so it is crucial to assess if NPD occurs in isolation or conjunction with another psychiatric condition. Grandiosity, irritability, and increased goal-directed activities are common symptoms of a manic or hypomanic episode in bipolar spectrum illness. However, there is no decreased need for sleep in isolated NPD. Additionally, manic and hypomanic episodes are acute episodes that are relatively short-lived and respond to medication treatment. In contrast, NPD is chronic and rigid and does not respond well to medication treatments.[27]

Other differential diagnoses include the other cluster B personality disorders, antisocial personality disorder, histrionic personality disorder, and borderline personality disorder. It bears mention that persons with NPD do not show overt signs of impulsivity and self-destructiveness associated with borderline personality disorder.[45] Similarly, apparent emotional responses are associated with histrionic personality disorder. NPD is most similar to antisocial personality disorder, with a lack of empathy and superficial charm. However, people with an antisocial personality disorder would show a lack of morals compared with people with NPD and have a past diagnosis of conduct disorder from adolescence.[46]

Pertinent Studies and Ongoing Trials

There is a generally limited understanding of NPD, with high-quality population studies lacking. Most of our current knowledge is based on small sample-size investigations, case reports, or case series. Additionally, there are significant limitations to the existing models for describing all personality disorders. The cluster system has been most commonly utilized due to its implementation in the DSM. Despite behavioral similarity patterns that have been best attempted to be classified into syndromes (personality disorders), the individual uniqueness of each personality remains a problem for the diagnosis and research into each specific personality disorder.[8] 

Experts in personality disorders have suggested switching to a dimensional model of personality rather than a cluster model. The proposed dimensional models describe temperament, utilization of defense mechanisms, and identification of pathological personality traits.[47] Although the DSM-5 did not incorporate these recommendations due to the sudden radical change it would imply for clinical use, the paradigm will likely shift in the coming decades as further research solidifies in congruence with evolving clinical guidelines. This evolution is particularly evident as the DSM-5-TR incorporated this research into publication under the "emerging measures and models" section. Notably, in this section of the DSM-5-TR, some of the cluster model personality disorders have been removed, but NPD remains a named personality disorder.

Prognosis

Limited studies report and predict the outcome of NPD, although there is a consensus that the disorder usually lasts for life.[27] An investigation from DSM-III era criteria found that NPD was less likely to have long-term impairment of global functioning compared to schizoid, antisocial, borderline, histrionic, and avoidant personality disorders.[48] Ultimately, NPD is unlikely to resolve on its own or with treatment. Still, interventions to optimize quality of life, including reducing psychiatric comorbidity and stabilizing social factors, are likely to improve the prognosis of NPD.[42]

Complications

Substance use disorders are common among personality disorders but with limited implications into which specific personality disorders pose the most risk for a particular substance use disorder.[49] Personality disorders have an increased likelihood of suicide and suicide attempts compared to those without personality disorders, and individuals with NPD should be screened for suicidal ideation regularly.[42][50]