The exact cause of SPD is unknown. Many factors may be involved:

• Genetic -- SPD seems to be more common among relatives of people with SPD. Studies have shown that some gene variants are found more often in people with SPD.
• Psychological -- A person's personality, ability to deal with stress, and handle relationships with others may contribute to SPD.
• Environmental -- Emotional trauma as a child and chronic stress may also play roles in developing SPD.

SPD should not be confused with schizophrenia. People with SPD can have odd beliefs and behaviors, but unlike people with schizophrenia, they are not disconnected from reality and usually do not hallucinate. They also do not have delusions.

People with SPD may be very disturbed. They may also have unusual preoccupations and fears, such as fear of being monitored by government agencies.

More commonly, people with this disorder behave oddly and have unusual beliefs (such as believing in aliens). They cling to these beliefs so strongly that they have difficulty forming and keeping close relationships.

People with SPD may also have depression. A second personality disorder, such as borderline personality disorder, is also common. Mood, anxiety, and substance use disorders are also common among people with SPD.

Common signs of SPD include:

• Discomfort in social situations
• Inappropriate displays of feelings
• No close friends
• Odd behavior or appearance
• Odd beliefs, fantasies, or preoccupations
• Odd speech

SPD is diagnosed based on a psychological evaluation. The health care provider will consider how long and how severe the person's symptoms have been.

Talk therapy is an important part of treatment. Social skills training can help some people cope with social situations. Medicines may also be a helpful addition if mood or anxiety disorders are also present.

SPD is usually a long-term (chronic) illness. The outcome of treatment varies based on the severity of the disorder.

Complications may include:

• Poor social skills
• Lack of interpersonal relationships

See your provider or a mental health professional if you or someone you know has symptoms of SPD.

There is no known prevention. Awareness of risk, such as a family history of schizophrenia, may allow early diagnosis.

Personality disorder - schizotypal

American Psychiatric Association. Personality disorders. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR). Washington, DC: American Psychiatric Association Publishing; 2022.

Blais MA, Rivas-Vazquez RA, Ruchensky JR, Stein MB. Personality and personality disorders. In: Stern TA, Wilens TE, Fava M, eds. Massachusetts General Hospital Comprehensive Clinical Psychiatry. 3rd ed. Philadelphia, PA: Elsevier; 2025:chap 37.

Rosell DR, Futterman SE, McMaster A, Siever LJ. Schizotypal personality disorder: a current review. Curr Psychiatry Rep. 2014;16(7):452. PMID: 24828284 pubmed.ncbi.nlm.nih.gov/24828284/.

Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.