Persons with schizotypal Personality Disorder lack social and interpersonal skills. They are not able to have close social relationships and feel discomfort in social situations. To the people around a person with a Schizotypal Personality Disorder, the person shows strange, bizarre behaviour with a tendency to social retraction.

Furthermore they suffer from distortions of perception and cerebration, which is quite similar to cognitive defects occurring in Schizophrenia (More). This is why people with schizotypal Personality Disorder have a higher risk of developing Schizophrenia (More).

These symptoms are for example:

• Paranoid ideas
• Depersonalisation (More info)
• Derealisation
• Superstitiousness
• Etc.

Because of these schizophrenical Symptoms, in the ICD-10 this disorder is classified under Schizophrenia (More).

Additionally, this Personality Disorder often co-occurs with Borderline Personality Disorder (More).

Diagnostic Criteria of DSM-IV

The DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) describes Schizotypal Personality Disorder as a pervasive pattern of social and interpersonal deficits marked by acute discomfort with, and reduced capacity for, close relationships as well as by cognitive or perceptual distortions and eccentricities of behaviour, beginning in early adulthood and present in a variety of contexts, as indicated by five (or more) of the following:

• ideas of reference (excluding delusions of reference);
• odd beliefs or magical thinking that influences behaviour and is inconsistent with subcultural norms (e.g., superstitiousness, belief in clairvoyance, telepathy, or "sixth sense"; in children and adolescents, bizarre fantasies or preoccupations);
• unusual perceptual experiences, including bodily illusions;
• odd thinking and speech (e.g., vague, circumstantial, metaphorical, over-elaborate, or stereotyped);
• suspiciousness or paranoid ideation;
• inappropriate or constricted affect;
• behaviour or appearance that is odd, eccentric, or peculiar;
• lack of close friends or confidants other than first-degree relatives;
• excessive social anxiety that does not diminish with familiarity and tends to be associated with paranoid fears rather than negative judgments about self.

To justify this diagnosis, the symptoms should not occur exclusively during the course of Schizophrenia (More), a Mood Disorder With Psychotic Features, another Psychotic Disorder, or a Pervasive Developmental Disorder (more).