658 Personality Disorders
Gender-Related Diagnostic Issues
Schizotypal personality disorder may be slightly more common in males.
Differential Diagnosis
Other mental disorders with psychotic symptoms. Schizotypal personality disorder
can be distinguished from de lusional disorder, schizophrenia , and a bipolar or depressive
disorder with psychotic features because thes e disorders are all characterized by a period
of persistent psychotic symptoms (e.g., delu sions and hallucinations). To give an addi-
tional diagnosis of schizotypal personality disorder, the personality disorder must have
been present before the onset of psychoti c symptoms and persis t when the psychotic
symptoms are in remission. Wh en an individual has a persist ent psychotic disorder (e.g.,
schizophrenia) that was preceded by schizo typal personality disorder, schizotypal per-
sonality disorder should also  be recorded, followed by “premorbid” in parentheses.
Neurodevelopmental disorders. There may be great difficulty differentiating children
with schizotypal personality disorder from the heterogeneous group of solitary, odd chil-
dren whose behavior is characterized by mark ed social isolation, eccentricity, or peculiar-
ities of language and whose diagnoses woul d probably include milder forms of autism
spectrum disorder or language communicat ion disorders. Commun ication disorders may
be differentiated by the primacy and severity of the disorder in language and by the char-
acteristic features of impaired language found in a specialized language assessment.
Milder forms of autism spectrum disorder are differentiated by the even greater lack of so-
cial awareness and emotional reciprocity and stereotyped behaviors and interests.
Personality change due to another medical condition. Schizotypal personality disor-
der must be distinguished from personality change due to another medical condition, in