Objective: Lack of insight into illness is common in patients with schizophrenia diagnoses. It is supposed to reflect deficits of executive functioning that are frequently assessed with the Wisconsin Card Sorting Test. Studies on the remediability of WCST deficits in schizophrenia, however, raise doubts about its construct validity and suggest the use of a dynamic pretest-training-posttest paradigm (WCSTdyn) and single-case analysis (Reliable Change Index, RCI) in studies on insight. Moreover, a multifactorial etiology with neurocognitive and motivational factors, as suggested by Startup's (1996) model, has to be taken into consideration. The model hypothesizes a quadratic function of the relationship between insight and cognition, which means that both cognitively impaired and cognitively intact patients with low insight are to be expected. Method: Three interrelated studies on WCSTdyn and insight were conducted. In study 1, the split-half reliability of the WCST-128 was investigated in a non-psychiatric sample (N = 110). Study 2 compared different RCI single-case tests of significance of intraindividual change on data from N = 400 patients with schizophrenia diagnoses. Furthermore, a typology with three homogenous subgroups was developed and first steps toward an external validation were taken. In study 3, the three types of test-takers were compared on two measures of insight (Item G12 of the Positive and Negative Syndrome Scale [PANSS]; Osnabrueck Scale of Therapeutic Attitudes and Identification of Psychological Problems in Schizophrenia [OSSTI]). The model by STARTUP (1996) was tested by means of regression and cluster analyses including scales on coping (Freiburg Questionnaire of Coping with Illness, FKV: MUTHNY, 1989) and defensiveness (Eppendorf Schizophrenia Inventory, ESI-FR: MAß, 2001; N = 85).
Results: The WCST-64 was sufficiently stable (r_tt = .70 [Total Number Correct]). Concordances of different RCI methods were high (kappa = .72 - .90). 45 % of the sample consisted of high scorers, in 43 % a low initial score could be normalized by a short training intervention (learners), and in only 12 % of the sample the WCST deficits were not amenable to training (nonlearners). Insight of nonlearners was significantly reduced (G12: g = 0,45). Finally, three clusters were identified with configurations of insight and WCSTdyn scores consistent with the prediction by STARTUP (1996). Patients with intact neurocognition but low insight responded in a significantly more defensive manner (g = 0,38). They did not differ in self-rated coping, however. A quadratic relationship could not be confirmed. Conclusion: The RCI-based performance typology developed in studies 1 and 2 is a universally applicable analytic tool for future studies on insight-limiting neurocognitive deficits with the WCSTdyn. Results from study 3 point in the direction of a multifactorial etiology of lack of insight in schizophrenia with differential contributions of neurocognitive deficits (e.g., interference control) and defensiveness.
| Identifer | oai:union.ndltd.org:uni-osnabrueck.de/oai:repositorium.ub.uni-osnabrueck.de:urn:nbn:de:gbv:700-201012136727 |
| Date | 13 December 2010 |
| Creators | Waldorf, Manuel |
| Contributors | Prof. Dr. Karl H. Wiedl, apl. Prof. Dr. Henning Schöttke |
| Source Sets | Universität Osnabrück |
| Language | German |
| Detected Language | English |
| Type | doc-type:doctoralThesis |
| Format | application/pdf, application/zip |
| Rights | http://rightsstatements.org/vocab/InC/1.0/ |
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