The Rorschach Perceptual-Thinking Index (PTI): An Examination of Reliability, Validity, and Diagnostic Efficiency

Abstract

This study investigates the reliability, validity, and diagnostic efficiency of the Rorschach Perceptual-Thinking Index (PTI) in relation to the accurate identification of psychotic disorder (PTD) patients. The PTI is a revision of the Rorschach Schizophrenia Index (SCZI), designed to achieve several criteria, including an increase in the diagnostic utility of the Rorschach for assessing thought disorder and to increase clinical focus on the dimensional aspects of impaired perceptions and thoughts (Exner, 2000a; 2000b). Seventy-eight patients who met DSM-IV criteria for a PTD or Axis II disorder [PTD = 33; borderline personality disorder (BPD) = 23; cluster A personality disorders (CA) = 9; cluster C personality disorders (CC) = 13] and 40 non-patients were compared on the PTI. The results of this study indicate that the PTI can be reliably scored and is internally consistent. In addition, the PTI can be used to effectively differentiate PTD patients from a non-patient sample as well as from personality disorder patients characterized by moderate to, at times, severe perceptual thought disorder. Finally, the PTI can also be employed for classification purposes in ways that are clinically meaningful in the diagnosis of a psychotic disorder. Conceptual and methodological issues are discussed in relation to the assessment of psychosis.

Keywords:

• borderline personality disorder
• perceptual–thinking index
• psychometric features
• psychotic disorder
• rorschach
• schizophrenia

Notes

^a XA (Extended Form Appropriate) % = all responses with FQ+, FQo, or FQu divided by R (where R = number of responses).

^b WDA (W, D Appropriate) % = all W, WS, D, and DS responses with FQ+, FQo, or FQu divided by the sum of all W, WS, D, or DS responses.

^c If R < 17: for ages 5 to 7, WSum6 > 16, for ages 8 to 10, WSum6 > 15, for ages 11 to 13, WSum6 > 14.

^d If R > 16: for ages 5 to 7, WSum6 > 20, for ages 8 to 10, WSum6 > 19, for ages 11 to 13, WSum6 > 18.

^a XA (Extended Form Appropriate) % = sum of FQ+, FQo, and FQu responses divided by R (where R = number of responses).

^b WDA (W, D Appropriate) % = sum of W, WS, D, and DS responses with FQ+, FQo, or FQu divided by the sum of all W, WS, D, or DS responses.

^c X+ (Conventional Form) % = sum of FQ+ and FQo responses divided by R.

^d X− (Distorted Form) % = sum of FQ- responses divided by R.

^e S− (White Space Distortion) % = sum of FQ- responses with white space divided by sum of FQ- responses.

^f FQ− = sum of FQ− responses.

^g FQu = sum of FQu responses.

^h FQo/+ = sum of FQo/+ responses.

ⁱ LVL2 = sum of Level 2 special scores.

^j FAB2 = number of FABCOM Level 2 special scores.

^k Raw Sum6 = total number of all special scores.

^l Weighted SUM6 = weighted sum of all special scores.

^m M− = number of human movement responses with FQ−.

ⁿ GHR = number of Good Human Representations scores.

^o PHR = number of Poor Human Representations scores.

^p EII-2 = Ego Impairment Index.

^q SCZI = Schizophrenia Index.

^r PTI = Perceptual-Thinking Index.

*** p < .0001.

* = p < .05,

** = p < .005,

*** p < .0001.

^a XA (Extended Form Appropriate) % = sum of FQ+, FQo, and FQu responses divided by R (where R = number of responses).

^b WDA (W, D Appropriate) % = sum of W, WS, D, and DS responses with FQ+, FQo, or FQu divided by the sum of all W, WS, D, or DS responses.

^c X+ (Conventional Form)% = Sum of FQ+ and FQo responses divided by R.

^d X− (Distorted Form) % = sum of FQ- responses divided by R.

^e S− (White Space Distortion) % = sum of FQ- responses with white space divided by sum of FQ- responses.

^f FQ− = sum of FQ− responses.

^g FQu = sum of FQu responses.

^h FQo/+ = sum of FQo/+ responses.

ⁱ LVL2 = sum of Level 2 special scores.

^j FAB2 = number of FABCOM Level 2 special scores.

^k Raw Sum6 = total number of all special scores.

^l Weighted SUM6 = weighted sum of all special scores.

^m M− = number of human movement responses with FQ−.

ⁿ GHR = number of Good Human Representations scores.

^{a o} PHR = number of Poor Human Representations scores.

^p EII-2 = Ego Impairment Index.

^q SCZI = Schizophrenia Index.

^r PTI = Perceptual-Thinking Index.

^a R = number of responses.

^b XA (Extended Form Appropriate) % = sum of FQ+, FQo, and FQu responses divided by R (where R = number of responses).

^c WDA (W, D Appropriate) % = sum of W, WS, D, and DS responses with FQ+, FQo, or FQu divided by the sum of all W, WS, D, or DS responses.

^d X+ (Conventional Form) % = sum of FQ+ and FQo responses divided by R.

^e X− (Distorted Form) % = sum of FQ− responses divided by R.

^f S− (White Space Distortion) % = sum of FQ− responses with white space divided by sum of FQ− responses.

^g FQ− = sum of FQ− responses.

^h FQu = sum of FQu responses.

ⁱ FQo/+ = sum of FQo/+ responses.

^j LVL2 = sum of Level 2 special scores.

^k FAB2 = number of FABCOM Level 2 special scores.

^l Raw Sum6 = total number of all special scores.

^m Weighted SUM6 = weighted sum of all special scores.

ⁿ M− = number of human movement responses with FQ−.

^o GHR = number of Good Human Representations scores.

^p PHR = number of Poor Human Representations scores.

^q EII-2 = Ego Impairment Index.

^r SCZI = Schizophrenia Index.

^s PTI = Perceptual-Thinking Index.