Schizotypal disorders

Schizophreniform disorder in DSM-FV is somewhat different from schizotypal disorder in ICD-10. The diagnosis of schizophreniform disorder requires the identical criteria of schizophrenia (criterion A), except for two differences the total duration of the illness is at least 1 month, but less than 6 months (criterion B), and impaired social or occupational functioning during some part of the illness is not required. The delusional disorder in DSM-IV corresponds more or less to the category persistent delusional disorder of ICD-10, and brief psychotic disorder (DSM-IV) is similar to the ICD-10 category acute and transient psychotic disorder, whereas the shared psychotic disorder of DSM-IV corresponds to induced delusional disorder of ICD-10. 

In one single-blind study, 17 schizotypal patients were given a modest dose of halopehdol (i.e., 2 to 12 mg per day), which produced some benefit, although many were sensitive to the adverse effects of this drug (216). The study by Goldberg et al. (217) also found that thiothixene benefited both schizotypal disorder and borderline personality disorder (BPD). Similarly, low-dose antipsychotics had a modest effect in patients with both schizotypal and obsessive-compulsive personality disorders (218). 

They also developed two measures of anhedonia a 61-item Physical Anhedonia Scale (PhA Chapman, Chapman, Raulin, 1976) and a 40-item Revised Social Anhedonia Scale (RSAS Eckblad, Chapman, Chapman, Mishlove, 1982). All four measures utilize a true or false format. The PAS, the MIS, and the RSAS assess features of schizotypy that are also included in the definition of schizotypal personality disorder, while physical anhedonia is not an explicit part of the DSM criteria. With this in mind, let us review schizotypy literature. 

Fossati, A., Maffei, C., Battaglia, M., Bagnato, M., Donati, D., Donini, M., et al. (2001). Latent class analysis of the DSM-IV schizotypal personality disorder criteria in psychiatric patients. Schizophrenia Bulletin, 27, 59-71. 

Cluster A Personality Disorders (Schizotypal PD, Schizoid PD, Paranoid PD). These are the odd and eccentric personality disorders. They all share certain features in common with schizophrenia, but schizotypal PD in particular appears to be most closely related to schizophrenia. The schizophrenia-like symptoms of these personality disorders (e.g., magical thinking, paranoia, social withdrawal) are less severe and generally don t impair social or employment function as severely as schizophrenia. 

Research into the risk factors for Cluster A personality disorders has focused on genetic factors. In particular, many researchers have looked for a shared genetic linkage between these disorders and schizophrenia. Only schizotypal personality appears to be genetically linked to schizophrenia. It may be that STPD exists on a biological continuum with schizophrenia. In other words, STPD could theoretically be a far milder variant of Axis I schizophrenia. There is less evidence linking PPD or SPD to schizophrenia nevertheless, certain characteristic symptoms of these other disorders also overlap with schizophrenia. 

The limited research data available also suggests a role for antidepressants in the treatment of patients with STPD. We recommend using a SSRl/SNRl antidepressant that conld theoretically address both depressive symptoms and those of the personality disorder. In our experience, schizotypal patients can nsnally tolerate a more conventional dose increase schedule than can patients with PPD. 

Delusional Disorder and Schizotypal Personality Disorder. In onr experience, patients with BPD at times resemble those with Clnster A personality disorders or those with an Axis 1 psychotic disorder. Psychotic symptoms in the BPD patient, although intense, tend to arise in the context of some stressor and to be relatively short-lived. This usually takes the form of a brief psychotic disorder. Placing the BPD patient in a structured and supportive environment usually hastens the resolution of these psychotic symptoms. By contrast, the psychotic symptoms of a patient with a delusional disorder or a Cluster A personality disorder are long-term and potentially intractable even with antipsychotic treatment. 

Schizophrenia, Schizotypal, and Delusional Disorders (ICD-10) Schizophrenia and Other Psychotic Disorders (DSM-IV)... 

Caplan, R., Perdue, S., Tanguay, R, and Fish, B. (1990) Formal thought disorder in childhood onset schizophrenia and schizotypal personality disorder. / Child Psychol Psychiatry 31 1103-1114. 

Pervasive developmental disorder NOS is diagnosed when there is a severe and pervasive impairment in the development of reciprocal social interaction. Impairment in verbal and nonverbal communication skills and stereotyped behavior, interests, and activities may be present, but the criteria are not met for a specific PDD, schizophrenia, schizotypal personality disorder. 

Jenike MA, Surman OS, Cassem NH, et al Monoamine oxidase inhibitors in obsessive-compulsive disorder. J Clin Psychiatry 144 131-132, 1983 Jenike MA, Baer L, Minichiello WE, et al Concomitant obsessive-compulsive disorder and schizotypal personality disorder. Am J Psychiatry 143 530-533, 1986 Jenike MA, Flyman S, Baer L, et al A controlled trial of fluvoxamine in OCD. Am J Psychiatry 147 1209-1215, 1990... 

Cadenhead. K.S., Swerdlow. N R Shafer. K.M., et al Modulation of the startle response and startle laterality in relatives of schizophrenic patients and in subjects with schizotypal personality disorder, evidence of inhibitory deficits. Am. J. Psychiatry 157, 1660-1668, 2000. 

In one series of nine patients who received open antipsychotic augmentation of fluvoxamine (with or without lithium), those who had co-morbid tic disorder or schizotypal personality disorder were further benefited. In another nine patients who did not have either of these disorders, only two were helped by antipsychotic augmentation (237). 

BPD can be life-threatening with a stormy course, at times necessitating inpatient hospitalization, or it can be a milder disorder managed on an outpatient basis. Thus, because one sample of patients may be more severely disturbed or has more psychotic features than another, discrepancies in outcome among studies may be due to these differences. In addition, because several studies combine schizotypal and BPDs, it is important to separate these patients when analyzing the results. 

Hymowitz P, Frances A, Jacobsberg L, et al. Neuroleptic treatment of schizotypal personality disorder. Compr Psychiatry 1986 27 267-271. 

Goldberg SC, Schulz SC, Schulz PM, et al. Borderline and schizotypal personality disorders treated with low-dose thiothixene vs placebo. Arch Gen Psychiatry 1986 43 680-686. 

Markowitz PJ, Calabrese JR, Schulz SC, et al. Fluoxetine treatment of borderline and schizotypal personality disorder. Am J Psychiatry 1991 148 1064-1067. 

Several studies have looked at schizophrenia spectrum disorders and results have been less clear than for first-degree relatives. For instance, coherent motion thresholds, PI amplitude, contrast sensitivity, and form and trajectory discrimination were not impaired (Farmer et al., 2000 O Donnell et al., 2006 Vohs et al., 2008) in schizotypal personality disorder. However, a backward masking deficit was found in schizotypal personality disorder (Cadenhead et al., 1999). 

Cadenhead KS, Perry W, Shafer K, Braff DL. 1999. Cognitive functions in schizotypal personality disorder. Schizophr Res 37 123-132. 

Farmer CM, O Donnell BF, Niznikiewicz MA, Voglmaier MM, McCarley RW, et al. 2000. Visual perception and working memory in schizotypal personality disorder. Am J Psychiatry 157 781-788. 

O Donnell BF, Bismark A, Hetrick WP, Bodkins M, Vohs JL, et al. 2006. Early stage vision in schizophrenia and schizotypal personality disorder. Schizophr Res 86 89-98. 

Vohs JL, Hetrick WP, Kieffaber PD, et al. 2008. Visual event-related potentials in schizotypal personality disorder and schizophrenia. J Abnorm Psychol 117 119-131. 

Dickey CC, McCarley RW, Voglemaier MM, Frumin M, Niznikiewicz MA, et al. 2002. Smaller left Heschl s gyrus volume in patients with schizotypal personality disorder. Am J Psychiatry 159(9) 1521-1527. 

Fukuzako H, Kodama S, Fukuzako T. 2002. Phosphorus metabolite changes in temporal lobes of subjects with schizotypal personality disorder. Schizophr Res 58 201-203. 

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