Narcissistic personality disorder (NPD) is one of 10 diagnosable personality disorders that appear in the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5), all of which are retained from the fourth edition of the manual. NPD is grouped with antisocial personality disorder, borderline personality disorder, and histrionic personality disorder to form the cluster B personality disorders, which share the features of extreme affect, theatricality, and unpredictability. The general criteria for NPD are an exaggerated and unrealistic sense of superiority, a need for admiration, and an inability to understand the feelings of others, starting by early adulthood and present in different areas of functioning. To diagnose NPD, at least five of the nine specific following criteria must be met: inflated and unjustified self-regard, with expectations that others will concur; an inordinate focus on having success, power, and unrealistic relationships; belief that one is superior and can only be understood by persons or institutions with the same superior standing; a constant demand for attention and extreme praise; belief that one deserves special treatment above and beyond others, and that others should unquestioningly carry out any request; an exploitative view of relationships; failure to acknowledge or understand the feelings or needs of others; belief that others are envious of one, or being envious of others; and exhibiting arrogance in interpersonal interactions. The grandiosity and beliefs of a person with NPD may manifest as either fantasy or actual behavior. Furthermore, such fantasies and beliefs are different from the bizarre delusions associated with psychotic disorders in that the fantasies and beliefs are possible, in principle, no matter how embellished or distorted.
Although they are not included in the DSM-5, there are two subtypes of NPD recognized in the clinical setting: grandiose, or overt, and vulnerable, or covert. Individuals with the grandiose subtype of NPD tend more toward overt displays of self-importance, entitlement, fantasies of admiration, denial of weakness, and exploitative behavior,whereas those with the vulnerable subtype tend more toward hypersensitivity to insult; self-criticism; feelings of shame, helplessness, or inadequacy; and social withdrawal. It is theorized that the subtypes develop because of the different approaches of earlier caregiver(s): overly indulgent with extravagant praise versus cold with excessive expectations. Both approaches adversely affect attachment and development of healthy self-esteem.