Psychotic-like anomalous self-experiences in feeding and eating disorders: Their role in eating psychopathology through the mediation of body uneasiness and embodiment and identity disorders

Early Interv Psychiatry. 2024 Apr 13. doi: 10.1111/eip.13527. Online ahead of print.

Abstract

Background: Psychotic-like anomalous self-experiences (ASEs) are core and early features of schizophrenia spectrum disorders, which have been recently also postulated to underlie embodiment disturbance in feeding and eating disorders (FEDs). The present study was aimed at investigating the interplay between ASEs and specific psychopathology in FED.

Methods: Ninety persons with Anorexia Nervosa and 41 with Bulimia Nervosa were evaluated with the inventory of psychotic-like anomalous self-experiences (IPASE), identity and eating disorders (IDEA), body uneasiness test (BUT), and eating disorder examination questionnaire (EDE-Q). The same assessment was performed for 92 subjects recruited from the general population. Structural equation modelling was employed to test the role of embodiment/identity disorders in mediating the relationship between ASEs and ED psychopathology.

Results: Patients with FED displayed high scores on IPASE, comparable with people with schizophrenia spectrum disorders. A significant correlation was also demonstrated between IPASE, BUT and EDE-Q. All IPASE domains were strongly related to feeling extraneous from one's own body by IDEA. All IPASE domains demonstrated a high relationship with BUT Depersonalization scale. A strong correlation was also reported between total scores of IPASE and IDEA. The mediation model confirmed that ASEs impact on FED symptomatology through the mediation of both embodiment/identity disorders and body image.

Discussion: Anomalous interoceptive processes may represent the first step of a maladaptive process-impairing embodiment, selfhood, and identity in FED. Assessment of ASEs might be a valid tool to identify an early-shared vulnerability of severe disorders characterized by embodiment alterations.

Keywords: anorexia nervosa; bulimia nervosa; clinical staging models; eating disorders; phenomenology.