(See also Overview of Personality Disorders.)
In schizotypal personality disorder, cognitive experiences reflect a more florid departure from reality (eg, ideas of reference, paranoid ideas, bodily illusions, magical thinking) and a greater disorganization of thought and speech than occurs in other personality disorders.
Reported prevalence of schizotypal personality disorder varies, but estimated prevalence is about 3.9% of the general US population. This disorder may be slightly more common among men.
Comorbidities are common. Over half of patients with schizotypal personality disorder have had ≥ 1 episode of major depressive disorder, and 30 to 50% of them have major depressive disorder when schizotypal personality disorder is diagnosed. These patients often also have a substance use disorder.
Etiology of schizotypal personality disorder is thought to be primarily biologic because it shares many of the brain-based abnormalities characteristic of schizophrenia. It is more common among 1st-degree relatives of people with schizophrenia or another psychotic disorder.
Patients with schizotypal personality disorder do not have close friends or confidants, except for 1st-degree relatives, They are very uncomfortable relating to people. They interact with people if they have to but prefer not to because they feel like they are different and do not belong. However, they may say their lack of relationships makes them unhappy. They are very anxious in social situations, especially unfamiliar ones. Spending more time in a situation does not ease their anxiety.
These patients often incorrectly interpret ordinary occurrences as having special meaning for them (ideas of reference). They may be superstitious or think they have special paranormal powers that enable them to sense events before they happen or to read other people's minds. They may think that they have magical control over others, thinking that they cause other people to do ordinary things (eg, feeding the dog), or that performing magical rituals can prevent harm (eg, washing their hands 3 times can prevent illness).
Speech may be odd. It may be excessively abstract or concrete or contain odd phrases or use phrases or words in odd ways. Patients with schizotypal personality disorder often dress oddly or in an unkempt way (eg, wearing ill-fitting or dirty clothes) and have odd mannerisms. They may ignore ordinary social conventions (eg, not make eye contact), and because they do not understand usual social cues, they may interact with others inappropriately or stiffly.
Patients with schizotypal personality disorder are often suspicious and may think others are out to get them.
For a diagnosis of schizotypal personality disorder, patients must have
This pattern is shown by the presence of ≥ 5 of the following:
Ideas of reference (notions that everyday occurrences have special meaning or significance personally intended for or directed to themselves) but not delusions of reference (which are similar but held with greater conviction)
Odd beliefs or magical thinking (eg, believing in clairvoyance, telepathy, or a sixth sense; being preoccupied with paranormal phenomena)
Unusual perceptional experiences (eg, hearing a voice whispering their name)
Odd thought and speech (eg, that is vague, metaphorical, excessively elaborate, or stereotyped)
Suspicions or paranoid thoughts
Incongruous or limited affect
Odd, eccentric, or peculiar behavior and/or appearance
Lack of close friends or confidants, except for 1st-degree relatives
Excessive social anxiety that does not lessen with familiarity and is related mainly to paranoid fears
Also, symptoms must have begun by early adulthood.
The primary diagnostic challenge is to differentiate schizotypal personality disorder from
Differential diagnosis also includes the following:
General treatment of schizotypal personality disorder is the same as that for all personality disorders.
Schizotypal personality disorder is commonly treated with drugs. Atypical antipsychotics lessen anxiety and psychotic-like symptoms; antidepressants may also help lessen anxiety in patients with schizotypal personality disorder.
Cognitive-behavioral therapy that focuses on acquiring social skills and managing anxiety can help. Such therapy can also increase patients' awareness of how their own behavior may be perceived.
Supportive psychotherapy is also useful. The goal is to establish an emotional, encouraging, supportive relationship with the patient and thus help the patient develop healthy defense mechanisms, especially in interpersonal relationships.