The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (American Psychiatric Association, 1994, pg. 641) describes Schizoid Personality Disorder as a pervasive pattern of detachment from social relationships and a restricted range of expression of emotions in interpersonal settings, beginning by early adulthood and present in a variety of contexts, as indicated by four (or more) of the following:
* neither desires nor enjoys close relationships, including being part of a family;
* almost always chooses solitary activities;
* has little, if any, interest in having sexual experiences with another person;
* takes pleasure in few, if any, activities;
* lacks close friends or confidants other than first-degree relatives;
* appears indifferent to the praise or criticism of others;
* shows emotional coldness, detachment, or flattened affectivity.
