Schizotypal personality disorder
[6] They frequently interpret situations as being strange or having unusual meanings for them; paranormal and superstitious beliefs are common.
People with StPD usually disagree with the suggestion that 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.
Abnormal facial expressions are also common in people with StPD, and they can have aberrant eye movements and difficulty responding to stimuli.
[80] It is common for people with StPD to feel déjà vu or as if they can accurately predict future events due to abnormalities in the brain's memory storage.
[83][82] Its diagnosis was developed through differentiating the classifications of borderline personality disorder, of which some of the diagnosed population demonstrated schizophrenia-spectrum traits.
[83][82] When the separation of borderline personality disorder and StPD was originally suggested by Spitzer and Endicott, Siever and Gunderson opposed the distinction.
[85] Spitzer and Endicott stated "We believe, as do the authors, that the evidence for the genetic relationship between Schizotypal features and Chronic Schizophrenia is suggestive rather than proven".
[86] A large American study found a lifetime prevalence of 3.9%, with somewhat higher rates among men (4.2%) than women (3.7%).
[87] Together with other cluster A personality disorders, it is also very common among homeless people who show up at drop-in centers, according to a 2008 New York study.
[90] Traits of StPD usually remain consistently present over time,[91][92] although can fluctuate greatly in severity and stability.
[119][120] This may lead to impaired capacities for decision-making,[121] speech,[122] cognitive flexibility,[123] and altered perceptual experiences.
[141][142][143] It may lead to abnormally low levels of Glutamic acids in the NMDA receptors, which impairs memory and learning.
Higher levels of dopamine in the brain,[152][153] possibly specifically the D1 receptor,[154][155][156] might contribute to the development of StPD.
[161][162][163][164] People with StPD may also have decreased volumes of grey or white matter in their caudate nucleus,[165][166] which leads to difficulties in speech.
[180][181] StPD symptoms may also be influenced by reduced internal capsule,[182][183][184] which carries information to the cerebral cortex.
[186] People with StPD have reduced levels of gray matter in their middle frontal gyrus and Brodmann area 10.
[201][202][203][204] Unique environmental factors, which differ from shared sibling experiences, have been found to play a role in the development of StPD and its dimensions.
[205][206][207] Neglect, abuse, stress,[208] trauma,[209][210][211] or family dysfunction during childhood may increase the risk of developing schizotypal personality disorder.
[214] 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.
Another possibility is that they were excessively criticized or felt like they were constantly under threat,[216] potentially resulting in the onset of social anxiety, strange thinking patterns,[217] and blunted affect present in StPD.
[73] Children with schizotypal symptoms usually are more likely to indulge in internal fantasies,[220] more anxious, socially isolated, and more sensitive to criticism.
[227] A method that measures the risk of developing psychosis through self-reports is the Wisconsin Schizotypy Scale (WSS).
[231] In order to develop better screening tools, researchers are looking into the importance of ipseity disturbance, which is characteristic of schizophrenia spectrum disorders such as StPD but not of autism.
[236][237] 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.
[258] The antipsychotics which show promise as treatments for StPD include olanzapine,[259] risperidone,[260][261] haloperidol,[262] and thiothixene.
[264][265] 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 antipsychotic drug exposure.
[264] Those with comorbid OCD and StPD were most positively affected by the use of olanzapine, and showed worse outcomes with the use of clomipramine, an antidepressant.
[281] Support is especially important for schizotypal patients with predominant paranoid symptoms, because they may have difficulties even in highly structured groups.
