Schizotypal Personality Disorder 655
are in remission. When an individual has a pe rsistent psychotic diso rder (e.g., schizophre-
nia) that was preceded by schizoid person ality disorder, schizoid personality disorder
should also be recorded, followe d by “premorbid” in parentheses.
Autism spectrum disorder. There may be great difficulty di fferentiating individuals with
schizoid personality disorder from those with milder forms of autism spectrum disorder,
which may be differentiated by more severely  impaired social inte raction and stereotyped
behaviors and interests.
Personality change due to another medical condition. Schizoid personality disorder
must be distinguished from personality ch ange due to another medical condition, in
which the traits that emerge ar e attributable to the effects of another medical condition on
the central nervous system. 
Substance use disorders. Schizoid personality disorder must also be distinguished
from symptoms that may develop in a ssociation with persistent substance use.
Other personality disorder s and personality traits. Other personality disorders may be
confused with schizoid personality disorder because they have certain features in com-
mon. It is, therefore, import ant to distinguish among these disorders based on differences
in their characteristic features. However, if an individual has personality features that
meet criteria for one or  more personality disorders in addition to schizoid personality dis-
order, all can be diagnosed. Although characteri stics of social isolation and restricted af-
fectivity are common to schizoid, schizotypal, and paranoid personality disorders,
schizoid personality disorder can be distin guished from schizotypa l personality disorder
by the lack of cognitive and perceptual dist ortions and from paranoid personality disorder
by the lack of suspiciousness and paranoid ideation. The social isolation of schizoid per-