Correlation between attenuated psychotic experiences and depressive symptoms among Japanese students

Aims: To examine the emergence of attenuated psychotic experiences, self-disturbance or affective symptoms among younger subjects in the general population and to investigate the intergroup differences on each symptom between adolescents and post-adolescents. Methods: A total of 781 participants, 496 university students (mean age: 19.3 +/- 1.1 years) and 285 high school students (mean age: 16.0 +/- 0.3 years), were administered self-reported questionnaires. Psychotic prodromal symptoms were evaluated using the PRIME Screen-Revised (PS-R), a 12-item self-reported questionnaire. To measure the cognitive, emotional and physical symptoms associated with depression, the Zung Self-rating Depression Scale (ZSDS), a 20-item self-reported questionnaire, was administered. Results: There were no intergroup differences on the factor score of the PS-R, except the self-demarcation factor (post-adolescents > adolescents), whereas there were significant differences in the factor score of the ZSDS, except for the anxiety factor. Among the post-adolescents, the factors of the PS-R showed a moderate correlation to the cognitive factor on the ZSDS; among the adolescents, the PS-R factors showed a greater correlation to the anxiety factor on the ZSDS than other factors. There were no differences in the distribution of each item of the PS-R between the two groups. Conclusions: The disturbance of self results in difficulty to precisely objectify, especially among adolescents, which would induce more primitive reactions such as agitation, irritability or anxiety; probably, the self disturbance would become an explicit symptom from an implicit experience with advancing age of the subject. Although these data are only preliminary, they could explain the pathway of progression prior to the onset of psychosis, from disturbance within the self to exaggerated self-absorption.