schizoid personality disorder is under cluster a (the odd eccentric cluster)
diagnostic criteria
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 to no interest in having sexual experiences with another person
.takes pleasure in little to no activities
.lacks close friends other than first degree relatives
.appears indifferent to the praise or criticism of others
.shows emotional coldness, detachment, or flattened affectivity
subtypes
languid - They experience a marked inertia and generally deficient activation level. They appear intrinsically phlegmatic, lethargic, weary, leaden, lackadaisical, exhausted, and enfeebled. They often are unable to act with spontaneity or seek the simplest pleasures, may experience profound angst, yet lack the vitality to express it strongly
remote - They appear distant and removed: inaccessible, solitary, isolated, disconnected, secluded, and aimlessly drifting. Tough, they are often peripherally occupied. This subtype is seen among people who would have been otherwise capable of developing normal emotional life but having been subjected to intense hostility lost their innate capability to form bonds. Some residual anxiety regarding this hostility is present.
depersonalized - They are disengaged from others and themselves. They see their “self” as a disembodied or distant object. Their body and mind are sundered, cleaved, dissociated, disjoined, or entirely eliminated eliminated. Often seen as simply staring into the empty space or being occupied with something substantial while actually being occupied with nothing at all.
affectless - They appear passionless, unresponsive, unaffectionate, chilly, uncaring, unstirred, spiritless, lackluster, unexcitable, unperturbed, and cold; all emotions having seemingly been diminished. They have a strong preference for rigid structures and unemotional logic.