Disturbed Experience of Self: Psychometric Analysis of the Self-Experience Lifetime Frequency Scale (SELF)

Background: Schizophrenia is characterized by positive and negative symptoms, but recently anomalous self-experiences, e.g. exaggerated self-consciousness (hyperreflectivity), receive more attention as an important symptom domain in schizophrenia patients. The semi-structured interview, the Examination of Anomalous Self-Experience (EASE) [Psychopathology 2005; 38: 236-258], examines experiences of a disturbed sense of self in a sophisticated but time-consuming manner. Therefore, we proposed the Self-Experience Lifetime Frequency scale (SELF), an instrument intended to screen for self-disturbance phenomena. Here we compared scores of patients, their siblings and healthy controls on the SELF. Methods and Sampling: The SELF is composed of a validated screener for symptoms of depersonalization complemented by questions covering several other domains of self-disturbance. A total of 426 patients with a psychotic disorder, 526 of their unaffected siblings, and 297 healthy controls completed the SELF. Patients' scores on the 12 items of the SELF were subjected to an explorative principal axis factor analysis (PAF); composite scores on factor components were compared between the three participant groups. Results: The PAF revealed two components, explaining 43.9 and 9.5% of variance, respectively. The first component represents a disturbance of self-awareness; the second component reflects (milder forms of) diminished self-affection or depersonalization. The two components of the SELF revealed good internal consistency (component 1, alpha = 0.88; component 2, alpha = 0.79; rho = 0.85). Patients showed significantly higher scores on both factor components in comparison with both siblings and controls. No significant differences were found between siblings and controls. Conclusions: The findings of the current study suggest that the SELF comprises two components of self-disturbance. Patients reported more (severe) symptoms of self-disturbance on both components, suggesting that it is feasible to screen for self-disturbance phenomena in patients with psychotic disorders with the SELF. Screening for symptoms of self-disturbance is important since these symptoms are associated with suffering and, moreover, these phenomena may mark the transition from intact to aberrant reality testing.