The main finding was that the psychometric properties of both subscales of the BCIS were acceptable for the schizophrenia and for the bipolar group. The scores of the controls, however, can not be compared to patient scores without excluding items referring to psychotic experiences. Furthermore, the two subscales self-reflectiveness and self-certainty showed low or moderate correlation for the three groups, indicating that they represent two different dimensions of cognitive insight.
Internal consistency for each subscale of the BCIS was consistent across groups, somewhat higher for self-reflectiveness than for self-certainty. Previous findings for the schizophrenia group [2
] were thereby replicated. These findings are also in line with the results by Warman et al.
] which point out that the factor loadings and internal consistencies of the BCIS were similar for healthy controls and the two groups of inpatients in Beck's original paper. To our knowledge the psychometric properties of the BCIS have not previously been published for a bipolar sample.
The psychometric properties of the BCIS were similar for normal controls to what we found in schizophrenia and bipolar disorder. However, the self-reflectiveness scores in the two patient groups were actually higher than in the control group, although not statistically significant.Similar findings concerning scores on subscale self-reflectiveness was found in a recent study by Warman et al.
] comparing scores of undergraduate students with patients diagnosed with schizophrenia or schizoaffective disorder. In this study the controls scored non-significantly lower on self-reflectiveness and significantly lower on self-certainty than subjects in the schizophrenia group. Similarly, in a study by Eric Granholm (personal communication) middle aged and older controls obtained self-reflectiveness and self-certainty scores that were lower than the patient scores in the Beck study.
We wanted to investigate if different scoring profiles were present in the three groups. Comparing scores across these groups on component I which includes "unusual experiences" disclosed a significantly lower score for controls than both patient groups. This discrepancy indicates that the control subjects interpret the statements of these particular items rather differently from the patients, which is understandable due to lack of psychotic experiences in this group. Control subjects and patients seem to have a different reference point for 4 out of the 9 items in self-reflectiveness. This implies that comparison of scores between control subjects and patients should be carried out only for component II. On the other hand, the two components within self-reflectiveness were fairly strongly correlated for all groups, and consequently, there was no clear indication that they constitute two separate dimensions. Provided that the scores of the controls are not compared with patients whose interpretation of items involving "unusual experiences" are likely to be different, all items in subscale self-reflectiveness might be applicable for controls for means of investigating relations between cognitive insight and other domains such as psychopathology.
We also investigated the scores on each of these components in our bipolar sample and found that the patients with and without previous psychotic episodes did not come out differently. This could be considered as additional support to the applicability of the scale in bipolar samples.
Self-reflectiveness and self-certainty were weakly or moderately intercorrelated in the groups suggesting that they represent different dimensions. Self-certainty showed a highly significant positive correlation with G12 scores in the schizophrenia group, indicating that mental inflexibility is possibly associated with poor clinical insight of illness. For self-reflectiveness a significant negative correlation was found for this group, suggesting that the capacity to reflect on anomalous experiences is linked to insight of illness. Further exploration of self-certainty could expand our knowledge of cognitive processes involved in insight of illness in general, and in particular comprehending patients' lack of insight related to treatment need. The relationship between poor mental flexibility and both symptoms and cognition are not known, and investigating these associations could represent important topics for future studies.