How is narcissistic personality disorder diagnosed?
The diagnosis of NPD can be made by a mental and behavioral health professional using DSM-5 diagnostic guidelines. There are no laboratory tests to diagnose any of the identified personality disorders. Instead, a careful interview and/or standardized questionnaires are used by the healthcare professional to obtain information, with a focus on the identification of long-term patterns of thinking, feeling, behaving and interacting that have caused ongoing distress or problems in relationships and life situations. The healthcare professional will determine if the key symptoms of NPD are present, while identifying and/or ruling out other mental health disorders that may be present. A medical history, physical exam and the use of various diagnostic tests — such as blood tests — are often important to rule out physical health problems as a cause of the symptoms.