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The etiopathogenetic mechanisms of lack of insight in patients with schizophrenia are to date unknown, although several hypotheses have been suggested. At first, lack of insight was understood as a denial of illness (for example, as an abnormal coping mechanism or an abnormal psychological defense) (1). A neuropsychological approach has also been described, and finally, an alternative clinical hypothesis has been proposed, based on the independence of lack of insight from positive and negative schizophrenia symptoms. This hypothesis considers that lack of insight arises directly from the illness process and can be considered as a “primary” and “basic” symptom, in Bleulerian terminology (2). The idea of a complex relation between insight and neuropsychological function induced some investigators, using the Wisconsin Card Sort Test (WCST), to explore insight impairment in subjects with schizophrenia, with positive findings (3–5). Conversely, other research groups did not find a significant relation between insight and neuropsychological performance (6–8). Evidence has also accumulated suggesting that this clinical issue can be identified in bipolar disorder (BD); impairment in insight may be a common feature of patients with BD (9).
Several studies have examined insight in mood disorders (9–12), and all show that lack of insight is relevant in BD at a level either equivalent to or slightly less pronounced than that found in schizophrenia. However, few studies have investigated the possible relation between neuropsychological indexes and the lack of insight in BD (3,6,8,13). In this study, we further explore the hypothesis that there is a relation between illness awareness and neuropsychological performance in patients with psychosis who suffer from either schizophrenia or BD. MethodsSubjects Procedure All subjects were administered the WCST, a measure of executive function and potential frontal lobe impairment (17); we used this task because of its well-known sensitivity to impairment in concept formation, cognitive flexibility, and abstract thought (4). We also evaluated the sample with the Scale for the Assessment of Positive Symptoms (SAPS) (18) and the Scale for the Assessment of Negative Symptoms (SANS) (19). We used Spearman’s rank correlation to establish the association between insight scores and the neuropsychological test results. To evaluate between-group differences, we used the Mann–Whitney U test, Student’s t-test, and 1-way analysis of variance (ANOVA). All analyses yielding a P-value of 0.05 were considered significant (20). ResultsTable 1 presents data on SAPS, SANS, SUMD, and WCST variables. The 2 groups did not differ significantly on any demographic variable. We found no differences between the 2 groups in SAPS mean global score, although schizophrenia patients showed a higher SANS mean global score (t = –3,66; df = 54; P = 0.001). Insight scores did not differ between the sexes or among the 2 diagnostic groups. Similarly, WCST scores did not differ between the 2 groups. One-way ANOVA comparisons of the 2 clinical groups and our WCST normal control subject data showed that both patient groups demonstrated cognitive impairment, although this was more relevant in the sample of schizophrenia patients (Table 1). Insight scores did not correlate with age, years of education, duration of illness, or neuroleptic dosages. None of the correlations between SANS, SAPS, WCST, and SUMD item scores were significant (P < 0.05), either for the total group or for the 2 groups, separately analyzed. DiscussionWe further explored the issue of the correlation between insight and neuropsychological function, adding evidence that lack of insight and performance on the WCST are independent. This finding is in line with some previous reports (for example, 21) but not with others, both in cases of schizophrenia and in cases of BD (2,21). The WCST may not specifically measure frontal lobe function, since frontal symptoms do not necessarily imply the presence of a frontal lesion but may rather be a common consequence of global cerebral impairment (22,23). However, if this test does measure frontal lobe impairment in patients with psychosis, the 3 insight dimensions (that is, awareness of mental disorder, awareness of social consequences of mental disorder, and awareness of benefits of medication) do not appear to be associated with frontal impairment. Conversely, because lack of insight is independent from positive and negative symptoms and from cognitive performance, the clinical hypothesis of insight mentioned above is reinforced. A possible limitation of the study is that we evaluated the patients in the remission phase of their illness, thereby probably lowering variance in both insight and symptoms and decreasing the chances of finding significant correlations. Interestingly, in an earlier evaluation of patients during an index acute psychotic episode (24), we found that lack of insight was more related to positive symptoms in the BD patients and more related to negative symptoms in the schizophrenia patients. Not surprising is the lack of difference in insight and WCST scores between the 2 sample groups: several studies suggest that BD patients with psychotic features are difficult to distinguish from schizophrenia patients, at least in a cross-sectional perspective (24–27). Further, we may have selected a sample of patients with particularly severe BD with psychotic symptoms, owing to the tertiary referral features of our centre. This sample may share features of cognitive dysfunction with the schizophrenia patients (28). Given the profound implications of lack of insight for the management of psychosis, this domain merits further research along phenomenological and neurobiologic lines of inquiry and is therefore the object of our ongoing research. References1. McGorry PD, McConville SB. Insight in psychosis: an elusive target. Compr Psychiatry1999;40:131–42. 2. Cuesta MJ, Peralta V. Lack of insight in schizophrenia. Schizophr Bull 1994;20:359–66. 3. Young DA, Zakzanis K, Bailey C, Davila R, Griese J, Sartory G, and others. Further parameters of insight and neuropsychological deficit in schizophrenia and other chronic mental disease. J Nerv Ment Dis 1998;186:44–50. 4. Lysaker PH, Bell MD, Bryson G, Kaplan E. Neurocognitive function and insight in schizophrenia: support for an association with impairments is executive function but not with impairments in global function. Acta Psychiatr Scand 1998;97:297–301. 5. Marks KA, Fastenau PS, Lysaker PM, Bond GR. Self-Appraisal of Illness Questionnaire (SAIQ): relationship to researcher rated insight an neuropsychological function in schizophrenia. Schizophr Res 2000;45:203–11. 6. Cuesta MJ, Peralta V, Caro F, de Leon J. Is poor insight in psychotic disorders associated with poor performance on the Wisconsin Card Sorting Test? Am J Psychiatry 1995;152:1380–2. 7. Collins A, Remington GJ, Coulter K, Birkett K. Insight, neurocognitive function and symptom clusters in chronic schizophrenia. Schizophr Res 1997;27:33–44. 8. Sanz M, Constable G, Lopez-Ibor I, Kemp R, David AS. A comparative study of insight scales and their relationship with psychopathological and clinical variables. Psychol Med 1998;28:437–46. 9. Pini S, Cassano GB, Dell’Osso L, Amador XF. Insight into illness in schizophrenia, schizoaffective disorder, and mood disorder with psychotic features. Am J Psychiatry 2001;158:122–5. 10. Michalakeas A, Skatas C, Charalambous A, Persteris A, MarinosV, Keramari E, and others. Insight in schizophrenia and mood disorders and its relation to psychopathology. Acta Psychiatr Scand 1994;90:46–9. 11. Ghaemi NS, Stoll AL, Pope HG. Lack of insight bipolar disorder. J Nerv Ment Dis 1995;183:464–7. 12. Peralta V, Cuesta MJ. Lack of insight in mood disorders. J Affect Disord 1998;49:55–8. 13. Ghaemi NS, Hebben N, Stoll A, Pope HG. Neuropsychological aspects of lack of insight in bipolar disorder: a preliminary report. Psychiatry Res 1996;65:113–20. 14. American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 4th ed. Washington (DC): American Psychiatric Association, 1994. 15. Kessler KA, Waletzky JP. Clinical use of the antipsychotics. Am J Psychiatry 1981;138:202–9. 16. Amador XF, Flaum M, Andreasen NC, Strauss DH, Yale SA, Clark SC, and others. Awareness of illness in schizophrenia and schizoaffective and mood disorders. Arch Gen Psychiatry1994;51:826–36. 17. Heaton RK. The Wisconsin Card Sorting Test manual Odessa (FL): Psychological Assessment Resources; 1981. 18. Andreasen NC. Scale for the assessment of positive symptoms (SAPS). Iowa City (IA): University of Iowa; 1984. 19. Andreasen NC. Scale for the assessment of negative symptoms (SANS). Iowa City (IA): University of Iowa; 1984. 20. Norusis MJ. SPSS for windows: base system user’s guide. Release 5.0. Chicago (IL): SPSS Inc; 1992. 21. David AS “To see ourselves as others see us” Aubrey Lewis’s insight. Br J Psychiatry 1999;175:210–6. 22. Robinson AL, Heaton RK, Lehman RA, Stilson DW. The utility of the Wisconsin Card Sorting Test in detecting and localizing frontal lobe lesions. J Consult Clin Psychol 1980;48:605–14. 23. Anderson SW, Damasio H, Jones RD, Tranel D. Wisconsin Card Sorting Test performance as a measure of frontal lobe damage. J Clin Exp Neuropsychol 1991;13:909–22. 24. Daneluzzo E, Arduini L, Rinaldi O, Di Domenico M, Petruzzi C, Kalyvoka A, and others. PANSS factors and scores in schizophrenic and bipolar disorders during an index acute episode: a further analysis of the cognitive component. Schizophr Res 2002;56:129–36. 25. Fennig S, Bromet EJ, Karant MT, Ram R, Jandorf L. Mood-congruent versus mood-incongruent symptoms in first-admission patients with affective disorder. J Affect Disord 1996;37:23–9. 26. Toomey R, Kremen WS, Simpson JC, Samson JA, Seidman LJ, Lyons MJ, and others. Revisiting the factor structure for positive and negative symptoms: evidence from a large heterogeneous group of psychiatric patients. Am J Psychiatry 1997;154:371–7. 27. Ratakonda S, Gorman JM, Yale SA, Amador XF. Characterization of psychotic conditions. Arch Gen Psychiatry 1998;55:75–81. Author(s)Manuscript received July 2002, revised, and accepted January 2003. 1. Physician, Clinical Psychological Unit, University of L’Aquila at Villa Serena, Città Angelo Pescara, Italy. 2. Physician, Institute of Experimental Medicine, University of L’Aquila, L’Aquila, Italy. 3. Physician, Deparment of Psychiatry, San Salvatore Hospital, L’Aquila, Italy. Address for Correspondence: Dr A Rossi, Dipartimento di Medicina Sperimentale, Via Vetoio, Coppito 67100, L’Aquila (AQ), Italy e-mail: rossi.aq@tin.it
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