Schizophrenia spectrum personality disorders in psychometrically identified schizotypes at two-year follow-up.

Earlier (Bolinskey et al., 2015), we reported that psychometrically identified schizotypes displayed greater symptom levels and higher incidences of schizophrenia spectrum (schizotypal, schizoid, paranoid, and avoidant) personality disorders (PDs). In this study, 49 schizotypes and 39 matched controls participated in follow-up assessments after two years. Participants were previously identified as schizotypes or controls based on scores on the Chapman Psychosis Proneness Scales (CPPS), and were interviewed at baseline and follow-up with the Personality Disorder Interview for DSM-IV (PDI-IV). At follow-up, schizotypes displayed significantly higher symptom levels compared to controls, with medium to large effects, and appeared to meet criteria for diagnosis of each PD more often than controls, although significant differences were only observed for paranoid PD. Overall, schizotypes were more likely to have met criteria for a diagnosis at either baseline or follow-up. Finally, we observed a widening disparity over time between schizotypes and controls in avoidant and schizoid PDs. These results suggest that schizophrenia spectrum PDs, as well as subthreshold symptoms of these disorders, can represent a greater liability for schizophrenia in individuals identified as at-risk on the basis of psychometric means only. Furthermore, these findings demonstrate that such differences persist, and in some cases increase, over time.

Further examination of the factor structure of the Chapman Psychosis Proneness Scales (CPPS).

Results of recent analyses of the Chapman Psychosis Proneness Scales (CPPS) have been inconsistent with regard to their factor structure. This inconsistency has involved whether the Revised Social Anhedonia Scale (SocAnh) reflects only the negative or both the negative and positive dimensions of schizotypy, along with the degree of correlation between these two dimensions. In the present study, confirmatory factor analysis was used to compare models created by Chan et al. and Kwapil et al.; a third model was constructed based on adjustments to these prior models and consideration of the schizotypy construct. Following Kwapil et al., our model allowed for bi-loading of SocAnh scale, but eliminated the correlation between positive and negative factors. Although fitness for each of the previously offered models was adequate, RMSEA and chi-square indicators suggested ideal fit for the model proposed by Kwapil and our new model, which redirects variance thought to be shared among the positive and negative dimensions to its specific source, SocAnh. The implications of these competing models with regard to our conceptualization of schizotypy are addressed. It is suggested that the cross loading of SocAnh reflects the notion of social anhedonia as the core of schizotypic personality organization.

Revisiting the blurry boundaries of schizophrenia: spectrum disorders in psychometrically identified schizotypes.

Certain Personality Disorders (PDs) have been found to be present in the prodromal phase of schizophrenia at a higher rate than other personality disorders. Although schizotypal, paranoid, and schizoid PDs are traditionally viewed as spectra for schizophrenia, research suggests that avoidant PD should be included in this group (e.g., Fogelson et al., 2007). The present study examines whether a sample of psychometrically identified schizotypes (SZT) have higher incidence of schizophrenia-spectrum PDs, as well as more symptoms of these PDs, in general, than does a matched comparison (MC) sample. Eighty-five SZT and 78 MC participants were administered the Personality Disorder Interview for DSM-IV (PDI-IV) to assess PD symptoms and diagnoses. Results indicate that the SZT group evidenced significantly more symptoms of avoidant, schizoid, paranoid, and schizotypal PDs than did the MC group. Further, there were significant differences in the incidence of these PDs between the groups.

Using the MMPI-2-RF to discriminate psychometrically identified schizotypic college students from a matched comparison sample.

This study investigates the extent to which the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF) profiles of 52 individuals making up a psychometrically identified schizotypes (SZT) sample could be successfully discriminated from the protocols of 52 individuals in a matched comparison (MC) sample. Replication analyses were performed with an additional 53 pairs of SZT and MC participants. Results showed significant differences in mean T-score values between these 2 groups across a variety of MMPI-2-RF scales. Results from discriminant function analyses indicate that schizotypy can be predicted effectively using 4 MMPI-2-RF scales and that this method of classification held up on replication. Additional results demonstrated that these MMPI-2-RF scales nominally outperformed MMPI-2 scales suggested by previous research as being indicative of schizophrenia liability. Directions for future research with the MMPI-2-RF are suggested.