Personality disorders often go untreated because the person suffering them does not realize they have a problem. For instance, if everything Trump does gets rewarded in some way (failed businesses, international banks prop him up; rapes ex-wife, gets new model wife), there is no incentive for him to seek treatment. That being said, there is no existing pharmacologic or non-pharmacologic effective treatment for NPD. I am not making a diagnosis here, but can provide legitimate information here regarding treatment. And regarding the post above deligitimizing psychology as a profession — you should do some reading on the lack of reliability of many medical tests, especially radiology. Most tests psychologists use currently have well over .80 reliability. DSM-5 does need some work, that’s for certain, but you obviously haven’t kept up with the science of psychology — sounds like you are reading some 1970’s texts and cite a single article from 1994. In all fairness, the main group making the diagnosis against the Goldwater standard was a group of psychiatrists from Harvard, not psychologists.