Schizotypal personality disorder (STPD or SPD), also known as schizotypal disorder, is a mental and

behavioral Behavior (American English) or behaviour (British English) is the range of actions and mannerisms made by individuals, organisms, systems or artificial entities in some environment. These systems can include other systems or organisms as we ...

disorder Disorder may refer to randomness, non-order, or no intelligible pattern. Disorder may also refer to: Healthcare * Disorder (medicine), a functional abnormality or disturbance * Mental disorder or psychological disorder, a psychological pattern ...

. DSM classification describes the disorder specifically as a

personality disorder Personality disorders (PD) are a class of mental disorders characterized by enduring maladaptive patterns of behavior, cognition, and inner experience, exhibited across many contexts and deviating from those accepted by the individual's cultu ...

characterized by

thought disorder A thought disorder (TD) is any disturbance in cognition that adversely affects language and thought content, and thereby communication. A variety of thought disorders were said to be characteristic of people with schizophrenia. A content-though ...

paranoia Paranoia is an instinct or thought process that is believed to be heavily influenced by anxiety or fear, often to the point of delusion and irrationality. Paranoid thinking typically includes persecutory beliefs, or beliefs of conspiracy c ...

, a characteristic form of

social anxiety Social anxiety is the anxiety and fear specifically linked to being in social settings (i.e., interacting with others). Some categories of disorders associated with social anxiety include anxiety disorders, mood disorders, autism spectrum disor ...

derealization Derealization is an alteration in the perception of the external world, causing those with the condition to perceive it as unreal, distant, distorted or falsified. Other symptoms include feeling as if one's environment is lacking in spontaneity, ...

, transient

psychosis Psychosis is a condition of the mind that results in difficulties determining what is real and what is not real. Symptoms may include delusions and hallucinations, among other features. Additional symptoms are incoherent speech and behavi ...

, and unconventional beliefs. People with this disorder feel pronounced discomfort in forming and maintaining social connections with other people, primarily due to the belief that other people harbor negative thoughts and views about them. Peculiar speech mannerisms and socially unexpected modes of dress are also characteristic. Schizotypal people may react oddly in conversations, not respond, or talk to themselves. They frequently interpret situations as being strange or having unusual meaning for them;

paranormal Paranormal events are purported phenomena described in popular culture, folk, and other non-scientific bodies of knowledge, whose existence within these contexts is described as being beyond the scope of normal scientific understanding. Not ...

and superstitious beliefs are common. Schizotypal people usually disagree with the suggestion their thoughts and behaviors are a 'disorder', and seek medical attention for depression or anxiety instead. Schizotypal personality disorder occurs in approximately 3% of the general population and is more commonly diagnosed in males.

History

The term "schizotype" was first coined by Sandor Rado in 1956 as a

portmanteau A portmanteau word, or portmanteau (, ) is a blend of wordspheno''type''". STPD is classified as a

cluster A Personality disorders (PD) are a class of mental disorders characterized by enduring maladaptive patterns of behavior, cognition, and inner experience, exhibited across many contexts and deviating from those accepted by the individual's culture ...

personality disorder, also known as the "odd or eccentric" cluster. STPD as a proper diagnosis was first introduced in 1980, with the release of the DSM-III. The diagnosis was created to fill the gap between

Borderline Personality Disorder Borderline personality disorder (BPD), also known as emotionally unstable personality disorder (EUPD), is a personality disorder characterized by a long-term pattern of unstable interpersonal relationships, distorted sense of self, and strong ...

(BPD) and moderate schizophrenia-like symptoms. Because of this, many early studies were either seeking to distinguish it from other diagnoses, specifically BPD, or identify its utility in recognizing non-clinical people who were genetically predisposed to schizophrenia. Very few changes were made from the DSM-IV-TR to the DSM-V in terms of the diagnostic criteria.

Causes

Genetic

Schizotypal personality disorder is widely understood to be a "

schizophrenia spectrum A spectrum disorder is a mental disorder that includes a range of linked conditions, sometimes also extending to include singular symptoms and traits. The different elements of a spectrum either have a similar appearance or are thought to be cause ...

" disorder. Rates of schizotypal personality disorder are much higher in relatives of individuals with schizophrenia than in the relatives of people with other mental illnesses or in people without mental illness. Technically speaking, schizotypal personality disorder may also be considered an "

extended phenotype ''The Extended Phenotype'' is a 1982 book by the evolutionary biologist Richard Dawkins, in which the author introduced a biological concept of the same name. The main idea is that phenotype should not be ''limited'' to biological processes suc ...

" that helps geneticists track the familial or genetic transmission of the genes that are implicated in

schizophrenia Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social w ...

pathogenesis. But there is also a genetic connection of STPD to mood disorders and depression in particular. Prediction of schizophrenia based on schizotypal traits has a higher accuracy for individuals with high genetic risk for STPD.

Social and environmental

Unique environmental factors, which differ from shared sibling experiences, have been found to play a role in the development of STPD and its dimensions. There is now evidence to suggest that parenting styles, early separation, trauma/maltreatment history (especially early childhood neglect) can lead to the development of schizotypal traits. Neglect or abuse, trauma, or family dysfunction during childhood may increase the risk of developing schizotypal personality disorder. There is also evidence indicating influenza in the prenatal environment could have an effect on development of STPD. Over time, children learn to interpret social cues and respond appropriately but for unknown reasons this process does not work well for people with this disorder. Schizotypal personality disorders are characterized by a common attentional impairment in various degrees that could serve as a marker of biological susceptibility to STPD. The reason is that an individual who has difficulties taking in information may find it difficult in complicated social situations where interpersonal cues and attentive communications are essential for quality interaction. This might eventually cause the individual to withdraw from most social interactions, thus leading to

asociality Asociality refers to the lack of motivation to engage in social interaction, or a preference for solitary activities. Asociality may be associated with avolition, but it can, moreover, be a manifestation of limited opportunities for social relat ...

Diagnosis

Screening

There are various methods of screening for schizotypal personality. The Schizotypal Personality Questionnaire (SPQ) measures nine traits of STPD using a self-report assessment. The nine traits referenced are Ideas of Reference, Excessive Social Anxiety, Odd Beliefs or Magical Thinking, Unusual Perceptual Experiences, Odd or Eccentric Behavior, No Close Friends, Odd Speech, Constricted Affect, and Suspiciousness. A study found that of the participants who scored in the top 10th percentile of all the SPQ scores, 55% were clinically diagnosed with STPD. A method that measures the risk for developing psychosis through self-reports is the Wisconsin Schizotypy Scale (WSS). The WSS divides schizotypal personality traits into 4 scales for Perceptual Aberration, Magical Ideation, Revised Social Anhedonia, and Physical Anhedonia. A comparison of the SPQ and the WSS suggests that these measures should be cautiously used for screening purposes of STPD.

STPD as a Personality Disorder

DSM-5

In the

American Psychiatric Association The American Psychiatric Association (APA) is the main professional organization of psychiatrists and trainee psychiatrists in the United States, and the largest psychiatric organization in the world. It has more than 37,000 members are invo ...

DSM-5 The ''Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition'' (DSM-5), is the 2013 update to the '' Diagnostic and Statistical Manual of Mental Disorders'', the taxonomic and diagnostic tool published by the American Psychiatri ...

, schizotypal personality disorder is defined 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 behavior, beginning by early adulthood and present in a variety of contexts." At least five of the following symptoms must be present: *

ideas of reference Ideas of reference and delusions of reference describe the phenomenon of an individual experiencing innocuous events or mere coincidences and believing they have strong personal significance. It is "the notion that everything one perceives in the ...

* strange beliefs or

magical thinking Magical thinking, or superstitious thinking, is the belief that unrelated events are causally connected despite the absence of any plausible causal link between them, particularly as a result of supernatural effects. Examples include the idea that ...

that influences behavior and is inconsistent with subcultural norms (e.g., superstitiousness, belief in clairvoyance, telepathy, or “sixth sense”, bizarre fantasies or preoccupations) * abnormal perceptual experiences, including bodily illusions * strange thinking and speech (e.g., vague, circumstantial, metaphorical, overelaborate, or stereotyped) * inappropriate or constricted affect * strange behavior or appearance * excessive social anxiety that does not diminish with familiarity and tends to be associated with paranoid fears rather than negative judgments about self These symptoms must not occur only during the course of a disorder with similar symptoms (such as schizophrenia or

autism spectrum The autism spectrum, often referred to as just autism or in the context of a professional diagnosis autism spectrum disorder (ASD) or autism spectrum condition (ASC), is a neurodevelopmental condition (or conditions) characterized by difficulti ...

disorder). The symptoms of "lacking close friends" and "suspiciousness or paranoia" have been used for diagnosing STPD by the DSM-V. These criteria overlap with symptoms for Paranoid personality disorder (PPD) and

Schizoid personality disorder Schizoid personality disorder (, often abbreviated as SzPD or ScPD) is a personality disorder characterized by a lack of interest in social relationships, a tendency toward a solitary or sheltered lifestyle, secretiveness, emotional coldness ...

(SzPD), making these symptoms not as useful when distinguishing STPD from other personality disorders.

STPD as a Clinical Disorder

ICD-10

The

World Health Organization The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level o ...

ICD-10 ICD-10 is the 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD), a medical classification list by the World Health Organization (WHO). It contains codes for diseases, signs and symptoms ...

uses the name ''schizotypal disorder'' (). It is classified as a clinical disorder associated with

, rather than a

as in

.
Schizotypal Disorder
'' in ICD-10
Clinical descriptions and guidelines.
The ICD definition is:

Diagnostic guidelines

This diagnostic rubric is not recommended for general use because it is not clearly demarcated either from simple schizophrenia or from schizoid or paranoid personality disorders, or possibly

autism spectrum disorder The autism spectrum, often referred to as just autism or in the context of a professional diagnosis autism spectrum disorder (ASD) or autism spectrum condition (ASC), is a neurodevelopmental condition (or conditions) characterized by difficulti ...

s as currently diagnosed. If the term is used, three or four of the typical features listed above should have been present, continuously or episodically, for at least two years. The individual must never have met criteria for schizophrenia itself. A history of schizophrenia in a first-degree relative gives additional weight to the diagnosis but is not a prerequisite.

Treatment

Medication

STPD is rarely seen as the primary reason for treatment in a clinical setting, but it often occurs as a comorbid finding with other mental disorders. When patients with STPD are prescribed pharmaceuticals, they are usually prescribed neuroleptics, also known as

antipsychotics Antipsychotics, also known as neuroleptics, are a class of psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), principally in schizophrenia but also in a range of ...

, of the sort used to treat

; however, the use of neuroleptic drugs in the schizotypal population is in great doubt. While people with schizotypal personality disorder and other attenuated psychotic-spectrum disorders may have a good outcome with neuroleptics in the short term, long-term follow-up suggests significant impairment in daily functioning compared to schizotypal and even schizophrenic people without neuroleptic drug exposure. Positive, negative, and depressive symptoms were shown to be improved by the used of olanzapine, a neuroleptic. Those with comorbid OCD and STPD were most positively affected by the use of

olanzapine Olanzapine (sold under the trade name Zyprexa among others) is an atypical antipsychotic primarily used to treat schizophrenia and bipolar disorder. For schizophrenia, it can be used for both new-onset disease and long-term maintenance. It is t ...

, and showed worse outcomes with the use of clomipramine, an antidepressant. Antidepressants are also sometimes prescribed, whether for STPD proper or for comorbid anxiety and depression. However, there is some ambiguity in the efficacy of antidepressants, as many studies have only tested people with STPD and comorbid obsessive-compulsive disorder or borderline personality disorder. They have shown little efficacy for treating

dysthymia Dysthymia ( ), also known as persistent depressive disorder (PDD), is a mental and behavioral disorder, specifically a disorder primarily of mood, consisting of similar cognitive and physical problems as major depressive disorder, but with l ...

and

anhedonia Anhedonia is a diverse array of deficits in hedonic function, including reduced motivation or ability to experience pleasure. While earlier definitions emphasized the inability to experience pleasure, anhedonia is currently used by researchers ...

related to STPD. Both of these medications are the most frequently prescribed medication for STPD, though the use and efficacy of them should be evaluated differently for every case. The use of stimulants have also shown some efficacy, especially for those with worsened cognitive and attentional issues. Patients that suffer from concurrent psychosis should be monitored more closely if stimulants are used as part of their treatment.

Therapy

According to

Theodore Millon Theodore Millon () (August 18, 1928 – January 29, 2014) was an American psychologist known for his work on personality disorders. He founded the '' Journal of Personality Disorders'' and was the inaugural president of the International Society ...

, schizotypal personality disorder is one of the easiest personality disorders to identify but one of the most difficult to treat with psychotherapy. Persons with STPD usually consider themselves to be simply eccentric or nonconformist; the degree to which they consider their social nonconformity a problem differs from the degree to which it is considered a problem in psychiatry. It is difficult to gain rapport with people with STPD due to the fact that increasing familiarity and intimacy usually increase their level of anxiety and discomfort. Group therapy is recommended for persons with STPD only if the group is well structured and supportive. Otherwise, it could lead to loose and tangential ideation. Support is especially important for schizotypal patients with predominant paranoid symptoms, because they will have a lot of difficulties even in highly structured groups.

Comorbidity

Schizotypal personality disorder frequently co-occurs with

major depressive disorder Major depressive disorder (MDD), also known as clinical depression, is a mental disorder characterized by at least two weeks of pervasive low mood, low self-esteem, and loss of interest or pleasure in normally enjoyable activities. Intro ...

and social phobia. Furthermore, sometimes schizotypal personality disorder can co-occur with

obsessive–compulsive disorder Obsessive–compulsive disorder (OCD) is a mental and behavioral disorder in which an individual has intrusive thoughts and/or feels the need to perform certain routines repeatedly to the extent where it induces distress or impairs general ...

, and its presence appears to affect treatment outcome adversely. Some people with a clinical diagnosis of OCD have been found to also possess many schizotypal personality traits resulting in what can be called ‘schizotypal OCD’. Without proper treatment, STPD tendencies, such as magical thinking and paranoid ideation, could worsen the symptoms of OCD in an individual. In terms of comorbidity with other personality disorders, schizotypal personality disorder has high comorbidity with schizoid and paranoid personality disorder, the other two 'Cluster A' conditions. Studies have found that cognitive impairment was worse in those with PPD or STPD, but the co-occurrence of the two had little impact. It also has significant comorbidity with borderline personality disorder and

narcissistic personality disorder Narcissistic personality disorder (NPD) is a personality disorder characterized by a life-long pattern of exaggerated feelings of self-importance, an excessive need for admiration, a diminished ability or unwillingness to empathize with oth ...

. Some schizotypal people go on to develop

, but most of them do not. There are dozens of studies showing that individuals with schizotypal personality disorder score similar to individuals with schizophrenia on a very wide range of neuropsychological tests.

Cognitive deficit Cognitive deficit is an inclusive term to describe any characteristic that acts as a barrier to the cognition process. The term may describe * deficits in overall intelligence (as with intellectual disabilities), * specific and restricted defic ...

s in patients with schizotypal personality disorder are very similar to, but quantitatively milder than, those for patients with schizophrenia. A 2004 study, however, reported neurological evidence that did "not entirely support the model that SPD is simply an attenuated form of schizophrenia".

Epidemiology

Reported prevalence of STPD in community studies ranges from 1.37% in a Norwegian sample, to 4.6% in an

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

sample.A large American study found a lifetime prevalence of 3.9%, with somewhat higher rates among men (4.2%) than women (3.7%). It may be uncommon in clinical populations, with reported rates of up to 1.9%. There is little known about the real world effect that STPD has on individuals. There does seem to be a relationship between STPD and not living on one's own or having a Bachelor's degree. People with STPD also seemed to be paid lower hours wages when compared to a healthy control group. The disorder also seems to be related to lack of employment, though this is specifically related to worsened cognitive impairment. Chance of STPD were seen highest in Black women, low socioeconomic people, and people separated from their partners, with the lowest rates in Asian men. Together with other

personality disorders, it is also very common among homeless people who show up at drop-in centers, according to a 2008 New York study. The study did not address homeless people who do not show up at drop-in centers. Adolescent cannabis users have an increased likelihood of self-reporting and possessing schizotypal personality disorder or traits consistent with STPD. Another epidemiological study on suicidal behavior in STPD found that, even when accounted for sociodemographic factors, people with STPD were 1.51 times more likely to attempt suicide. The same study found that people with childhood adversities, specifically abuse by a parent or caretaker, have a strongly significant association with lifetime STPD. Schizotypal disorder is over diagnosed in

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ...

and other

post-Soviet states The post-Soviet states, also known as the former Soviet Union (FSU), the former Soviet Republics and in Russia as the near abroad (russian: links=no, ближнее зарубежье, blizhneye zarubezhye), are the 15 sovereign states that wer ...

.Быкова А. Ю., Беккер Р. А., Быков Ю. В. О трудностях дифференциальной диагностики между первичным деперсонализационно-дереализационным расстройством и шизотипическим расстройством // Siberian Journal of Life Sciences & Agriculture. — 2022. — Т. 14. — №. 1.

References

External links

{{ICD-10 personality disorders Paranoia Cluster A personality disorders Schizophrenia