What is the youngest someone can be to get diagnosed with a personality disorder?

Early Adulthood On: For a formal diagnosis of pd the features have to extend back to late adolescence or early adulthood. But they need to have become stable over years. So, at first it is thought of as a provisional dx. Personality development disorder is a term used for younger people who are seen as likely to develop a pd. Milder forms might be called traits instead of disorders.