Narcissistic personalities are more likely to respond with anger or aggressiveness when presented with rejection. Because they are sensitive to perceived criticism or defeat, people with NPD are prone to feelings of shame, humiliation, and worthlessness over minor incidents of daily life and imagined, personal slights, and usually mask such feelings from people, by feigning humility, responding with outbursts of rage and defiance, or seeking revenge.The DSM-5 indicates that: "Many highly successful individuals display personality traits that might be considered narcissistic. Only when these traits are inflexible, maladaptive, and persisting, and cause significant functional impairment or subjective distress, do they constitute narcissistic personality disorder." Given the high-function sociability associated with narcissism, some people with NPD might not view such a diagnosis as a functional impairment to their lives. Although overconfidence tends to make people with NPD very ambitious, such a mindset does not necessarily lead to professional high achievement and success, because they refuse to take risks, in order to avoid failure or the appearance of failure. Moreover, the psychological inability to tolerate disagreement, contradiction, and criticism, makes it difficult for persons with NPD to work cooperatively or to maintain long-term, professional relationships with superiors and colleagues. Differential diagnosis
The occurrence of narcissistic personality disorder presents a high rate of comorbidity with other mental disorders. People with NPD are prone to bouts of psychological depression, often to the degree that meets the clinical criteria for a co-occurring depressive disorder. NPD is associated with the occurrence of bipolar disorder and substance use disorders, especially cocaine use disorder.
Generally, the symptoms of NPD also impair the persons psychological abilities to function socially, either at work or at school, or within important societal settings. The DSM-5 indicates that, in order to qualify as symptomatic of NPD, the persons manifested personality traits must substantially differ from social norms. ICD-11 and ICD-10
In the International Statistical Classification of Diseases and Related Health Problems, 11th Edition ICD-11 of the World Health Organization (WHO), all personality disorders are diagnosed under a single title called "personality disorder". The criteria for diagnosis are mainly concerned with assessing dysfunction, distress and maladaptive behavior as opposed to attributing specific personality traits. In the previous edition, the ICD-10, narcissistic personality disorder (NPD) is listed under the category of "other specific personality disorders". This means similarly to the ICD-11, the ICD-10 required that cases otherwise described as NPD in the DSM-5 would only need to meet a general set of diagnostic criteria. Associated features
People with NPD exaggerate their skills, accomplishments, and their degree of intimacy with people they consider high-status. A sense of personal superiority may lead them to monopolize conversations, look down on others or to become impatient and disdainful when other persons talk about themselves. This behavior correlates to an overall worse functioning in areas of life like work and intimate romantic relationships.People with NPD have been observed to use psychosocial strategies, such as the tendency to devalue and derogate and to insult and blame other people, usually with anger and hostility towards peoples responses to their anti-social behavior.