Other personality disorders such as antisocial personality disorder, borderline personality disorder, histrionic personality disorder, and schizotypal personality disorder are also common in people with NPD. Substance use disorders are among the most comorbid conditions.

NPD may coexist with other mental disorders rendering its diagnosis challenging. Prevalence rates can be from 1% to 15% of the United States population. However, in clinical settings, NPD appears to be more prevalent. Prevalence rates from community samples have been from 0.5% to 5% of the US population. Given the challenges of diagnosing narcissistic personality disorder, there have been varying reports of prevalence in the United States of America( USA). This paper aims to cover the gap and incite more research on NPD. Due to NPD comorbidity with other mental disorders and its elevated medical, social, and psychiatric complications, and a gap of knowledge about the disorder, understanding NPD is warranted. Experts such as Otto Kernberg and Eve Caligor have introduced more standardized evaluation tools to understand the disorder. NPD has been associated with the concept of ' development.' 'Development' has been central to studies that have been done to understand the psychopathology and etiology of NPD. Cluster B typically presents with overtly emotional and unpredictable behavior. Given the limited research on the same and differences in the diagnosis of the disease, it was initially going to be discontinued from the DSM.NPD is under the umbrella of Cluster B personality disorders, which include antisocial personality disorder, histrionic personality disorder, and borderline personality disorder. NPD is highly prevalent in society however, there has been limited research on the same.

Persons with NPD can often present with impairment in maintaining work and relationships. The disorder is classified in the dimensional model of 'Personality Disorders.'NPD is highly comorbid with other disorders in mental health. Narcissistic personality disorder (NPD) is a pattern of grandiosity, need for admiration, and lack of empathy per the Diagnostic and Statistical Manual of Mental Disorders ( DSM–5).

What is the meaning of narcissist