Clinical Dimensions of Delusional Beliefs: A Factor-Analytic Study

Abstract

We investigated the factorial composition as well as the demographic, anamnestic and clinical correlates of 13 features of delusional beliefs in a sample of 127 psychiatric inpatients with active delusions at the time of their assessment: Six factors were extracted, jointly accounting for 67.3% of the variance, which were interpreted as the dimensions of cognitive disintegration, volitional dyscontrol, doxastic strength, distress, incongruence and expansiveness, respectively. Moreover, most factors exhibited distinctive profiles of demographic, anamnestic or clinical correlates. Overall, our findings provide supportive evidence for both the clinical multidimensionality of delusional beliefs at the factor-analytic level and the – at least partial – external validity of the factorial solution obtained.

Dimensional approach to delusions in psychotic depression in the elderly: factor structure and clinical correlates

“…In the sole available study of psychotic depressives this factor was devoid of any significant correlates (Meyers et al, 2006). This factor was extracted in all relevant factor analytic studies, however conducted in patients suffering mainly from psychotic disorders (Kendler et al, 1983;Garety and Hemsley, 1987;Appelbaum et al, 1999;Oulis et al, 2000).…”

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“…Item C1 assesses the level of affect aroused by delusional experiences. Negative affect related to delusions has been enquired about in previous studies: concern [21], worry and unhappiness [22,23], anxiety [23], anger [23], and emotional impact [26]. In Item C2, the level of preoccupation with the experience is assessed.…”

“…In Item C2, the level of preoccupation with the experience is assessed. This characteristic has also been included in previous studies [21][22][23][24][25][26]. In Item C3, degree of inability to stop or be distracted from delusional thoughts is assessed.…”

“…Among current descriptive studies of psychotic experiences, Kendler et al [21] and others [22][23][24][25][26] conducted a series of investigations to identify basic features of delusions usable for PLOS ONE comprehending the experience. Characteristics assessed in these studies included conviction, preoccupation, extension (generalization), affective response (anxiety, unhappiness, etc.)…”

“…and systematization. In addition, Kendler et al [21] and Oulis et al [26] performed factor analytic studies on delusion characteristics, and extracted a number of principal features, such as those representing influence by delusion and disturbed thought process; however, the results of these two studies did not converge well. With the aim of bringing order to the vast variety of delusional symptoms, Spitzer [9] proposed a distinction between delusions about external reality and those concerning happenings within the patient's mind.…”