Research in Schizotypal Personality Disorder

Modern research has resulted in a better understanding of schizotypal personality disorder, which shines a better light on this often odd ailment that produces people with unique and eccentric thought processes. Schizotypal personality disorder is a Cluster A personality disorder that exhibits patterns of social and interpersonal deficits, as well as cognitive distortions and behavioral eccentricities (Butcher, Mineka & Hooley, 2010). Some of the symptoms can include ideas of reference (i.e. belief that conversations and gestures of others hold significant personal meaning), odd beliefs or magical thinking (even participating in magical rituals), unusual perceptual experiences, odd thinking and speech, suspicion or paranoia, inappropriate or extremely reserved emotional responses, odd or peculiar behavior and/or appearance, lack of close friends, and excessive social anxiety (anxiety that does not go away even after continued exposure to the stressor) (Butcher et al., 2010). Additionally, a person must not showcase these symptoms as a result of schizophrenia, mood disorder with psychotic features, pervasive developmental disorder, or any other psychotic disorder (Butcher et al., 2010). Many individuals suffering from schizotypal personality disorder tend to be introverted in their personality type, lack a large group of close friends, and are considered to be odd in their way of thinking, but not to the point that they would be labeled delusional or necessarily schizophrenic.

Schizotypal personality disorder is a disorder that in many ways is easy to misdiagnose. Symptoms like social anxiety are shared across a wide array of personality and mood disorders, while odd behavior, poor social skills and paranoia aren’t necessarily exclusive to the schizotypal diagnosis. Furthermore, the Diagnostic and Statistical Manual of Mental Disorder Text Revision Fourth Edition (DSM-IV-TR) mentions specifically that a diagnosis of schizotypal personality disorder should not be made if the symptoms are occurring during the course of other such disorders such as schizophrenia, pervasive development disorder and the others mentioned above (Butcher et al., 2010). Just the fact that the DSM-IV-TR has a criterion specially written for schizotypal personality disorder symptoms directing them to be exclusive of these other disorders shows the degree to which symptomatic behavior can overlap. Most often the diagnosis will fall to questions of magical thinking, odd beliefs, ideas of reference, peculiar behavior and other oddities that are mostly exclusive to SPD; however, one has to be careful not to confuse a person’s personal beliefs (influenced by family and culture) as symptoms of a disorder. As a result, therapists looking to diagnose someone with SPD not only have to be cautious of symptom overlap with other disorders, but also need to be conscientious and sensitive of a person’s cultural upbringing.

Etiology (Both Genetic and Environmental)

Psychology is wrought with the debate of nature versus nurture. In most cases, it seems to be the play between the two that leads to an outcome of one way or the other. As with most mental illnesses, research into schizotypal personality disorder has shown some genetic correlation. With the prevalence of schizotypal personality disorder hovering around two percent of the general population, research has classified heritability as moderate, but has shown a biological link with schizophrenia (Butcher et al., 2010). It is believed that schizotypal personality disorder is a part of the spectrum of schizophrenia that often occurs in relatives of people with schizophrenia (Butcher et al., 2010). This confirms that schizotypal personality disorder has not only shown a genetic link, but has also shown a genetic link to other mental illnesses.

When SPD was first established as a diagnostic category, biological studies of patients with the disorder were quick to spring up. These studies sought to better understand the diagnostic boundaries and effective treatments of the disorders (Siever, 1985). These studies revealed that the decreased activities of plasma amine oxidase, as well as platelet monoamine oxidase, are both correlated with SPD in families that show a history of schizophrenia (Siever, 1985). Many of these studies consistently showed the possibility of shared psychobiological abnormalities between SPD and schizophrenia (Siever, 1985). The importance in understanding the biological factors of SPD is that in uncovering the knowledge of why certain individuals remain in the more stable schizotypal personality disorder, while others end up suffering from schizophrenia, researchers may be able to find better treatment for both disorders.

Genetic inheritance, however, is not the only cause for schizotypal personality disorder or schizotypal symptoms. Psychological trauma, including early childhood trauma, has shown an increased prevalence of psychotic symptoms that may be associated with schizotypal personality disorder. Research by Berenbaum, Valera and Kerns (2003) used questionnaires and interviews to measure trauma history in women along with symptoms of SPD. As they had originally hypothesized, women with a history of trauma and maltreatment showed elevated schizotypal symptoms (Berenbaum, Valera & Kerns, 2003). The effects of trauma outside of the realm of posttraumatic stress disorder were highly correlated with schizotypal personality disorder and schizotypal symptoms.

As mentioned above, childhood trauma also shows a clear indication of being correlated with SPD and SPD symptoms. The study by Berenbaum et al. (2003) points out that childhood neglect was strongly associated with schizotypal symptoms. Furthermore, a second study by Steel, Marzillier, Fearon and Ruddle (2009) showed that there is an increasing body of evidence to suggest a correlation between childhood abuse and schizotypal symptoms. Using an Internet questionnaire, Steel et al. (2009) distinguished several different groups out of the participants, each of whom had experienced different types of childhood abuse. Individuals who had suffered physical or sexual abuse showed high levels of paranoia, suspiciousness and unusual perceptual experiences, but did not show signs of magical thinking (Steel, Marzillier, Fearon & Ruddle, 2009). Individuals who had suffered emotional abuse, on the other hand, did not show any of the signs of schizotypal behavior (Steel et al., 2009). Interestingly enough, magical thinking was found not to be associated with any form of childhood abuse at all (Steel et al., 2009). At the very least, the study by Steel et al. (2009) warrants further investigation into the various forms of abuse that a child suffers, and the onset of schizotypal personality disorder. This research, coupled with the Berenbaum et al. (2003) study mentioned earlier shows a clear indication that psychological trauma can be a cause leading to SPD.

In addition to biological and traumatic causes, SPD also has roots in some sociocultural and economic factors as well. It has long been understood that socioeconomic status has been identified as a potential risk for a variety of mood disorders (Cohen et al., 2008). Until recently, however, the development of personality disorders due to this risk had not been addressed. In longitudinal studies, Cohen et al. (2008) showed that low socioeconomic standing had a “robust modest independent effect” on both schizotypal and borderline personality disorders (p. 633). In these studies, the correlation was between parental socioeconomic status and their offspring’s symptoms of borderline or schizotypal personality disorder (Cohen et al., 2008).

In terms of cultural considerations, research is limited. Furthermore, the DSM-IV task force failed to create an even acceptance of cultural concepts during the construction of the DSM-IV-TR (Alarcon, 1996). Many cultural considerations are left out or uneven at best. For example, in regards to schizotypal personality disorder, the text on cultural aspects omits many examples derived from linguistic peculiarities, religious experiences and folk beliefs (Alarcon, 1996). With the term abnormal being such a subjective one, any clinician must be aware of cultural and religious beliefs that could, on the surface, appear to be schizotypal symptoms, such as magical thinking, participating in magical rituals, unusual perceptual experiences or odd thinking and speech. It could be very easy to look on these traits as symptoms of SPD rather than understanding them as cultural values held by the individual. The DSM-IV-TR does not provide this context in its symptomatic criteria.

Course of Treatment

Treatment of any personality disorder or mental illness in the schizophrenia spectrum can be accomplished by both medical and psychotherapeutic means. Schizotypal personality disorder is no exception. It has been noted that with schizotypal personality disorder sharing traits with the schizophrenia spectrum, individuals suffering from this disorder demonstrate increased dopamine transmission in the striatum in the brain (Woodward et al., 2010). Dopamine release in the striatum was positively correlated with overall schizotypal traits (Woodward et al., 2010). This has led to the conclusion that amphetamine-induced dopamine release may, in fact, be a useful endophenotype for further investigating the genetic aspects of schizotypal personality disorder, as well as other schizophrenia spectrum disorders (Woodward et al., 2010). A better understanding of the genetic basis for SPD and the biological aspects that make one more likely to develop the disorder is paramount to developing medications to appropriately control such conditions.

Interestingly enough, comorbidity with other disorders, such as mood disorders, can offer a look at the effectiveness of certain treatments. In a study by Fournier et al. (2008), those suffering from both depression and a personality disorder showed a greater response to antidepressant medication than those without the personality disorder. Furthermore, a sustained treatment of cognitive therapy and antidepressant medication showcased an identical response rate during a twelve month period (Fournier et al., 2010). It seems that mood altering medication can also be effective in combating personality disorder characteristics as well.

Schizotypal personality disorder is not associated with any specific track of drug treatment. Instead, most often, psychiatrists prescribe antidepressants or antipsychotics to alleviate any such associated conditions like depression and anxiety (Mayo Clinic Staff, 2010). It has been noted that risperidone and olanzapine are two medications that may, in fact, help to reduce symptoms such as distorted thinking (Mayo Clinic Staff, 2010). Additionally, amoxapine is a tricyclic antidepressant with antipsychotic properties that has been shown to be effective in improving schizophrenic-like symptoms in patients exhibiting schizotypal personality disorder (Encyclopedia of Mental Disorders, 2011). Although some drug treatments seem to be effective in combating symptoms, medication isn’t the only route.

While medication may be useful during psychotic episodes, some researchers believe that psychotherapy is still the most effective treatment. Due to the chronicity of the condition, long-term therapy becomes a necessity (Stone, 1985). Additionally, this long-term therapy often requires building a trusting relationship between the patient and the client. This bond of trust can help the SPD sufferer begin to develop trust in other interpersonal relationships (Mayo Clinic Staff, 2010). Furthermore, group therapy for support and modifications to socially awkward behavior, as well as social reeducation is a necessary addition to one-on-one psychotherapy (Stone, 1985). This group therapy could also involve family therapy, which helps in building support structures and morale – something that is also noted to help schizophrenic patients (Mayo Clinic Staff, 2010). Family and group support are known to be important structures in battling this mental illness.

In addition to a well rounded therapeutic relation, specific therapies can help with schizophrenic personality disorder. People with SPD often have deficits in social skills and behaviors. Specific behavioral therapy might help in teaching proper responses to social cues with more appropriate affect, vocal tone and/or facial expressions (Mayo Clinic Staff, 2010). Meanwhile, from a cognitive perspective, therapists might be able to help SPD sufferers identify and rectify any distorted thought patterns they might be having (Mayo Clinic Staff, 2010). The various types of therapy available all seem to offer something that can help with schizotypal personality disorder.
Standard psychotherapy also has a few ways in which it can deal with schizotypal personality disorder. In psychotherapy, the use of a more active and confrontational approach is preferred (Stone, 1985). Unlike mood disorders, which deal with an overreaction or under-reaction towards events in the real world, personality disorders such as SPD deal with patients that do not see the world in the manner in which it really exists (Stone, 1985). This can cause issues with logical reasoning skills, and with trying to get the therapist and the patient on the same page (and remaining there). This results in long-term therapy as the therapist must often repeat lessons endlessly in order to help restructure the cognitive patterns of the patient.

The Current State of Research

Recent research into schizotypal personality disorder has brought to light new advances in the understanding of the disorder. For example, new data in prosody (i.e. rhythm of speech, including stress and intonation) recognition suggests that differences between sufferers of SPD and a control group in phonological procession, IQ and executive functionality contribute to the difficulty in processing prosody in SPD sufferers (Obesity, Fitness & Wellness Week, 2010). This study actually backs up a previous study by McCarley et al. (2009) that looked at the poor prosody production in those with schizotypal personality disorder. A lot of recent research has been done in the area of sensory processing of prosody and the deficits found in those with schizotypal personality disorder.

In addition to the studies above on prosody deficits, Schizophrenia Research published quite a few articles in 2009 on related pitch, hearing and volume issues from which people with schizotypal personality disorder seem to suffer. In a study of superior temporal gyrus volumes, it was found that an auditory association area was dysfunctional in SPD sufferers, showing that patients had smaller volume than those in the control group and those suffering from borderline personality disorder (Goldstein et al., 2009). This study is important not only because of the association with superior temporal gyrus volumes, but also because of the implications that SPD sufferers do not share the deficit with the closely related borderline personality disorder. An additional study on dichotic listening showed that SPD subjects had lower accuracy scores in dichotic listening performance than a control group, but also showed that men with SPD generally suffered greater right ear performance deficits than women with SPD (Voglmaier et al., 2009). These results suggest that the left hemisphere temporal lobe may be somewhat involved in male onset SPD, but not so in women (Voglmaier et al., 2009). Understanding the reasons for this gender difference could help in future diagnosis and treatment. Finally, another study on abnormal pitch mismatch in people suffering from SPD concluded that sufferers exhibited signs of mismatch negativity compared to a control group (Niznikiewicz et al., 2009). This is in contrast to first episode schizophrenia, which often shows normal or non-significant reductions in mismatch negativity duration (Niznikiewicz, et al., 2009). Obviously this shows an important differentiation between schizophrenia and schizotypal personality disorder that can be useful in determining cause, onset and potential diagnosis. Psychologists have longed been searching for the differences and similarities between these two disorders, as well as the reasoning behind their relationship and differentiations.

All of these recent studies point to deficits in perceptual senses. The focus on physical characteristics of schizotypal personality disorder is helping to uncover biological, cognitive and sensory development issues that can help with differential diagnoses against other disorders, as well as uncover early onset indicators. This is important considering the difficult in an effective diagnosis separate from all other overlapping symptoms.

Summary and Conclusion

Schizotypal personality disorder is one of the most interesting of the personality disorders detailed in the DSM-IV-TR. Its overlapping symptoms with other personality disorders, as well as schizophrenia, make it hard to diagnose effectively, requiring the therapist to develop a detailed case and family history of the client in order to distinguish between it and possible other mental disorders (especially schizophrenia). Most often the analysis falls to examining the odd criteria of magical thinking, odd beliefs or speech, ideas of reference and other such traits that can often be misdiagnosed if a more cultural view is not taken of the patient. Diagnosis cannot rest solely on magical or odd thoughts, or else many current religious devotees, people subscribing to folk superstitions and modern occultists could quickly be lumped into a personality disorder based solely on their personal beliefs and a few odd behaviorisms. Different cultures treat what’s considered abnormal in different ways, and with the entire world becoming more and more global as a cultural melting pot, one cannot dismiss the cultural influence on an individual’s supposed odd beliefs. Even in the United States you can find odd beliefs, peculiar behavior and those that participate in magical rituals. Look at the New Age movement that was especially prevalent during the 90’s. How many of those New Age gurus would fit the criteria for schizotypal personality disorder? Does this mean that they truly have a disorder, or are we simply associating the term abnormal without something that does not normally fit into our frame of reference?

As you can see, even what was initially looked at as the simplest of schizotypal personality disorder traits to diagnose can have a trickier side of which we normally don’t think.

References

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