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.
Glycerol phenylbutyrate (USAN), trade name  Ravicti, is a medication used in the treatment of certain inborn urea cycle disorders. The medication works by preventing the harmful buildup of ammonia in the body. It is an FDA-approved prescription drug in the US. It is approved for anyone over 2 months of age. It was developed by Hyperion Therapeutics based on the existing drug Buphenyl, and received approval on February 1, 2013. Hyperion has been criticized for setting a high price for the drug. The price was set at US$250,000–290,000. In 2014, the drug generated $30.8 million in net sales, far behind the older and less expensive Buphenyl ($113.6 million in sales). In March 2015, Horizon Pharma acquired Hyperion Therapeutics and thus Raviciti. References
External links
"Glycerol phenylbutyrate". Drug Information Portal. U.S. National Library of Medicine.