Differentiation of Psychotic From Nonpsychotic Psychiatric Inpatients: The Rorschach Perceptual Thinking Index

Abstract

The aim of the study was to investigate the validity of the Rorschach Perceptual Thinking Index (PTI) to detect psychotic perceptual and thought disturbance in a sample of Slovene psychiatric inpatients. Using a sample of 275 adult psychiatric inpatients of both sexes, we examined the differences between patients with psychosis (PP) and patients with no psychotic features (NP) from various diagnostic groups on the global PTI and its subcomponent variables. PPs obtained significantly higher PTI scores, indicating more disturbed perception and more thinking disturbance, than NPs. No differences were found for diagnostic differences within the PP and NP groups. Results are in accordance with previous studies of the PTI as a valid cross-cultural index of perceptual and thinking disturbance.

Relationship between the Rorschach Perceptual Thinking Index (PTI) and the Positive and Negative Syndrome Scale (PANSS) in psychotic patients: A validity study

“…This suggests that these two abilities, when impaired in schizophrenia, remained largely stable (Exner et al, 1985). Our findings, together with the previous data, demonstrating the power and sensitivity of the PTI (Exner et al, 1985;Frank, 1990;Kleiger, 1999;Rosenbaum et al, 2012;Benedik et al, 2013), suggest that the PTI could be a reliable instrument in detecting the underlying deficits of psychotic disorders in reality testing, regardless of overt positive symptoms. Moreover, the structural difference between the Rorschach test and the PANSS scale could contribute to theoretically understanding this finding.…”

“…As hypothsized, the Rorschach PTI variables showed no significant differences between the acute and chronic psychosis groups. Previous studies have already demonstrated that the PTI variables are able to be used to differentiate between psychotic patients and healthy controls both in adults (Dao and Prevatt, 2006;Dao et al, 2008;Ilonen et al, 2010;Mihura et al, 2013;Benedik et al, 2013), and in adolescents (Smith et al, 2001); and that the PTI total score and the PANSS total score are significantly correlated (Dao and Prevatt, 2006). Moreover, previous meta-analyses reported high consistency of the Rorschach variable scores over time in longitudinal testing (Grønnerød, 2003;Grønnerød, 2006).…”

“…Several lines of evidence have suggested that the PTI may be useful in differentiating between psychotic and non-psychotic patients, even when comparing cross-culturally (Smith et al, 2001;Ritsher, 2004;Dao and Prevatt, 2006;Hilsenroth et al, 2007;Dao et al, 2008;Ilonen et al, 2010;Mihura et al, 2013;Benedik et al, 2013). Smith and colleagues demonstrated that the Rorschach variable M-, used to calculate the PTI, was a predictor of thought disorder (Smith et al, 2001), as it was correlated with the scores of the Behavior Assessment System for Children (Reynolds and Kamphaus, 1992) and Personality Inventory for Youth (Lachar and Gruber, 1995).…”

Cognitive-perceptual deficits and symptom correlates in first-episode schizophrenia

“…This finding would appear at first sight to be contradictory, since accurate form perception on the Rorschach is also viewed as a measure of reality testing. 12 Consequently, the question arises as to why subjects who achieved higher scores on measures of good form perception also scored higher on PANSS positive items that relate to delusions and hallucinations. Firstly, it is possible that individual items in the PANSS factor domain were responsible for the finding.…”

Rorschach Comprehensive System (RCS) for assessing disordered thought and perception.

“…With respect to its interpretive significance, a PTI positive for three of these five criteria begins to suggest difficulties in thinking logically and perceiving the world accurately, and the presence more than three is likely to identify an extent of cognitive dysfunction associated with schizophrenia spectrum or other psychotic disorders (Benedik et al, 2013;Biagiarelli et al, 2017;Dao & Prevatt, 2006;Hilsenroth et al, 2007). As shown in Table 8.1, a PTI > 3 rarely occurs in nonpatient adults (2%), adolescents (1%), and senior adults (3%).…”