schizoid personality disorder

Schizoid personality disorder (/ˈskɪtsɔɪd, ˈskɪdzɔɪd, ˈskɪzɔɪd/, often abbreviated as SzPD or ScPD) is a personality disorder characterized by a lack of interest in social relationships, a tendency toward a solitary or sheltered lifestyle, reservedness, emotional coldness, detachment, and apathy. Affected individuals may be unable to form intimate attachments to others and simultaneously possess a rich and elaborate but exclusively internal fantasy world. Other associated features include stilted speech, a lack of deriving enjoyment from most activities, feeling as though one is an "observer" rather than a participant in life, an intolerance towards meeting emotional expectations of others, apparent indifference when praised or criticized, being on the asexual spectrum, and idiosyncratic moral or political beliefs.

Symptoms typically start in late childhood or adolescence. The cause of SzPD is uncertain, but there is some evidence of links and shared genetic risk between SzPD, other cluster A personality disorders, and schizophrenia. Thus, SzPD is considered to be a "schizophrenia-like personality disorder". It is diagnosed by clinical observation, and it can be very difficult to distinguish SzPD from other mental disorders or conditions (such as autism spectrum disorder, with which it may sometimes overlap).