Assessment of self-disorders in a non-clinical population: Reliability and association with schizotypy

This study explores whether self-disorders occur and can be assessed reliably in a non-clinical sample, and whether the prevalence of these anomalies depends upon the degree of psychometrically defined schizotypy. Participants with either high (n=30) or low (n=20) schizotypy scores were interviewed using a modified version of the Examination of Anomalous Self-Experience (EASE). The degree to which interviewees experienced self-disorder symptoms was rated by the interviewer and an independent rater. Inter-rater reliability was calculated for each item, domain scores and the total score. For the total, sample most items (=66) showed substantial or perfect agreement (κ>0.61), with a few (=6) showing moderate agreement (κ>0.41). Reliability scores were only slightly lower when just the more homogeneous group of individuals with high Schizotypal Personality Questionnaire (SPQ) scores were examined. As expected, high SPQ scores were associated with a high level of self-disorders. In sum, the results suggest that self-disorders can be measured reliably in non-clinical samples and are particularly frequent in individuals with pronounced schizotypical traits.