Clinical correlates of hierarchically modeled perceptions of self & others in psychosis

Abstract

Introduction: The connection between self and psychosis has been qualitatively noted for centuries, but left relatively neglected in the field of quantitative psychology research. Some targeted studies have shown that self-concept is different in patients with psychosis than healthy volunteers. Studies of individuals have established a specific relationship between distortions of self and the content of delusions. Recent studies have begun to collect evidence of changes of self in the early stages of psychosis. Research suggests that delusions and self-concept have various shared cognitive mechanisms and neuroanatomy, particularly with respect to persecutory delusions. Changes in self-concept are apparent in persons at ultra high risk for developing psychosis, suggesting that it precedes specific symptomatology and could be at the root of delusion formation. Therefore, we identify where the two domains intersect while overcoming the limitations of past studies such as considering only persecutory delusions, minimally defining self, and including patients with a wide range of diagnoses.

Methods: We consider delusions and self-concept in a patient group, consisting of 22 persons with first-episode schizophrenia spectrum disorders, and a group of 22 healthy volunteers. Delusional ideation is measured through the Peters et al Delusion Inventory (PDI) which derives a total, three subscores- Distress, Preoccupation, Conviction- and seven factor scores based on delusion content. Self-concept is quantified using hierarchical classification (HICLAS) analysis which generates numeric and visual outputs. It is important to specify that self is a deceivingly broad topic of which we will focus on the trait level- that is, which adjectives individuals use to describe their selves and others who are close to them. In addition to PDI and HICLAS evaluations, patients undergo clinical diagnoses and symptom ratings.

Results: While there was no diagnostic group difference in the PDI total or subscores, patients had more delusional ideation with respect to three types of content, as determined by the factor scores. HICLAS did not show group differences. However, patients and controls had different relationships between PDI and HICLAS measures, with patients showing a greater overall connection between the two domains. The specific results are discussed, including two qualitative case studies.

Conclusion: We conclude that the relationship between self-concept and schizophrenia is specific to delusions rather than general symptomatology. Relationships are drawn between the cognitive theories underlying each domain. The findings are important to theoretical understandings of self and delusions. Furthermore, it is hoped that advanced understanding of these topics can likely lead to new, targeted psychotherapeutic treatment approaches.