Personality disorders involve inflexible and mal adaptive patterns of behavior, that can and most often make a person become a misfit in the society. Some examples: persons who are aloof, have few or no friends, are indifferent to praise or criticism (schizoid personality) persons who have an overblown sense of self importance, require constant attention, and are likely to exploit others (Narcissistic personality) and persons who show chronic irresponsibility, lack of concern for others, and no remorse after a wrong doing (antisocial personality).
These conditions require psychological testing, diagnosis and treatment. The professionals involved in identifying, collecting information are social worker, testing, diagnosing by clinical psychologist and treating them is by psychiatrist.