Schizotypal Personality Disorder

Schizotypal Personality Disorder

Definition

Schizotypal PD (STPD) is a pervasive pattern of interpersonal deficits, cognitive and perceptual aberrations, and eccentrici-ties of behavior (American Psychiatric Association, 2000). The interpersonal deficits are characterized in large part by an acute discomfort with and reduced capacity for close relationships. The symptomatology of STPD has been differentiated further into components of positive (cognitive, perceptual aberrations) and negative (social aversion and withdrawal) symptoms comparable to the distinctions made for schizophrenia. The presence of STPD is indicated by five or more of the nine diagnostic criteria listed in the DSM-IV criteria for STPD.

Etiology and Pathology

There is substantial empirical support for a genetic association of STPD with schizophrenia which is not surprising given that the diagnostic criteria were obtained from the observations of biological relatives of persons with schizophrenia. Research has indicated further that the positive and negative symptoms may even have a distinct genetic relationship with the comparable symptoms of schizophrenia. This suggests that the influence of familial etiological factors determining the expression of these symptom dimensions reaches across the boundary of psychotic illness to phenomena currently classified under the rubric of personality.

A predominant model for the psychopathology of STPD is deficits or defects in the attention and selection processes that organize a person’s cognitive–perceptual evaluation of and relat-edness to his or her environment. These defects may lead to dis-comfort within social situations, misperceptions and suspicions, and to a coping strategy of social isolation. Correlates of central nervous system dysfunction seen in persons with schizophrenia have been observed in laboratory tests of persons with STPD, including performance on tests of visual and auditory attention (e.g., backward masking and sensory gating tests) and smooth pursuit eye movement. This dysfunction may be the result of dysregulation along dopaminergic pathways, which could be serving to modulate the expression of an underlying schizotypal genotype.

Differential Diagnosis

Avoidant personality disorder and STPD share the features of social anxiety and introversion, but the social anxiety of STPD does not diminish with familiarity, whereas the anxiety of avoid-ant PD (AVPD) is concerned primarily with the initiation of a relationship. STPD is also a more severe disorder that includes a variety of cognitive and perceptual aberrations that are not seen in persons with AVPD.

An initial concern of many clinicians when confronted with a person with STPD is whether the more appropriate diagno-sis is schizophrenia. Persons with STPD closely resemble persons within the prodromal or residual phases of schizophrenia. This differentiation is determined largely by the absence of a deterio-ration in functioning. It is indicated in DSM-IV that one should note that STPD is “premorbid” if the schizotypal symptoms were present prior to the onset of schizophrenia (American Psychiatric Association, 2000). Premorbid schizotypal traits will have prog-nostic significance for the course and treatment of schizophre-nia and such traits should then be noted. However, as discussed for SZPD, in most of these cases the schizotypal PD symptoms could then be readily understood as prodromal symptoms of schizophrenia.

Epidemiology and Comorbidity

STPD may occur in as much as 3% of the general population although most studies with semistructured interviews have sug-gested a somewhat lower percentage. STPD might occur some-what more often in males. STPD cooccurs most often with the schizoid, borderline, avoidant and paranoid personality disor-ders. Common Axis I disorders are major depressive disorder, brief psychotic disorder and generalized social phobia.

Course

STPD is classified within the same diagnostic grouping as schizo-phrenia in ICD-10 (World Health Organization, 1992) because of its close relationship in phenomenology, etiology and pathology. However, it is classified as a personality disorder in DSM-IV-TR (American Psychiatric Association, 2000) because its course and phenomenology are more consistent with a disorder of person-ality (i.e., early onset, evident in everyday functioning, charac-teristic of long-term functioning and egosyntonic). Persons with STPD are likely to be rather isolated in childhood. They may have appeared peculiar and odd to their peers, and may have been teased or ostracized. Achievement in school is usually impaired, and they may have been heavily involved in esoteric fantasies and peculiar interests, particularly those that do not involve peers. As adults, they may drift toward esoteric–fringe groups that support their magical thinking and aberrant beliefs. These activities can provide structure for some persons with STPD, but they can also contribute to a further loosening and deterioration if there is an encouragement of aberrant experiences. Only a small proportion of persons with STPD develop schizophrenia. The symptomatol-ogy of STPD does not appear to remit with age. The course ap-pears to be relatively stable, with some proportion of schizotypal persons remaining marginally employed, withdrawn, and tran-sient throughout their lives.

Treatment

Persons with STPD may seek treatment for their feelings of anxiousness, perceptual disturbances, or depression. Treatment of persons with STPD should be cognitive, behavioral, sup-portive and/or pharmacologic, as they will often find the inti-macy and emotionality of reflective, exploratory psychotherapy to be too stressful and they have the potential for psychotic decompensation.

Persons with STPD will often fail to consider their social isolation and aberrant cognitions and perceptions to be particu-larly problematic or maladaptive. They may consider themselves to be simply eccentric, creative, or nonconformist. Rapport can be difficult to develop as increasing familiarity and intimacy may only increase their level of discomfort and anxiety. They are unlikely to be responsive to informality or playful humor. The sessions should be well-structured to avoid loose and tangential ideation.

Practical advice is usually helpful and often necessary. The therapist should serve as the patient’s counselor, guide, or “auxiliary ego” to more adaptive decisions with respect to every-day problems (e.g., finding an apartment, interviewing for a job and personal appearance). Persons with STPD should also receive social skills training directed at their awkward and odd behavior, mannerisms, dress and speech. Specific, concrete discussions on what to expect and do in various social situations (e.g., formal meetings, casual encounters and dates) should be provided. The rate of progress will tend to be slow, and it is helpful if there remains a continuity in the therapeutic relationship.

Most of the systematic empirical research on the treatment of STPD has been confined to pharmacologic interventions. Low doses of neuroleptic medications (e.g., thiothixene) have shown some effectiveness in the treatment of schizotypal symptoms, particularly the perceptual aberrations and social anxiousness. Group therapy has also been recommended for persons with STPD but only when the group is highly structured and sup-portive. The emotional intensity and intimacy of unstructured groups will usually be too stressful. Schizotypal patients with predominant paranoid symptoms may even have difficulty in highly structured groups.