Everyone has a personality with character traits such as stinginess, generosity, arrogance and independence. But when these traits are rigid and self-defeating, they may interfere with functioning and even lead to psychiatric symptoms. Personality traits are formed by early adulthood, persist throughout life and affect every aspect of day to day behavior. Individuals with personality disorders often blame others for their problems.
Although professionals identify distinct personality disorders (anti-social, borderline, schizotypal, et al), some personality disordered individuals may not fit in a particular category and yet may clearly deserve this label.
Although classified as mental disorders they may be classified separately and distinguished from the Axis I Clinical Syndromes for some purposes.