Narcissistic personality disorder is a personality disorder that is shown by having a grandiose state of mind in young adults. The number of people with this disorder is highly disputed with some theories stating that it can be as high as one percent of the population. However, most experts agree that this is not the case and the actual statistics are much lower. Narcissistic personality disorder is also disputed as the cause. There are two basic theories. One being that the disorder is caused by early trauma causing developmental disorders. Another theory is that it is learned behavior that has no basis in a clinical cause. If the origin of the disease is clinical in nature and caused by early developmental issues, the hope for treatment is not good. Because it is not a psychological issue and there are no known medical treatments for the disease, if it is a physical issue, there may not be anything or much that can be done to treat it. However, if the disease is psychological in nature, there is hope for treatment. The behavior can be relearned to something that is more socially acceptable. However, those who are in treatment for this disease show slow progress if any at all. The reason for this is narcissists by their nature have an inflated view of themselves. Therefore they rarely think there is a problem. Even if they are in treatment, studies show it takes years to make any significant progress. Health insurance companies have varying policies on coverage for this disorder but for the length of time treatment is needed in order to be successful, there will likely need to be a significant out of pocket expense. Narcissistic personality disorder will cause problems at home and in a career. A narcissist will not be able to sustain a healthy relationship for very long and will also have significant problems in productive activities like work or school. They will believe they have a grand life with lots of friends and an unending opportunity for wealth or fame. They will react offensively when the reality of a situation intrudes and have a tendency to blame others for anything negative that may happen in their lives.