The psychosis spectrum and underlying factors in female youth with eating disorders: a cross-sectional observational experience sampling methodology study

Objective Recent reviews indicated that the psychosis spectrum co-occurs with disorders on the eating disorder (ED) spectrum, which might elucidate the low recovery rates. Consequently, the ED field is encouraged to better understand the interplay between these two spectra. This study examined whether female youth with EDs experience higher levels of psychotic phenomena than controls, including associations between different levels of (subclinical) psychosis and the factors negative affect (NA), self-esteem, stress, and ED severity. Method A cross-sectional study using experience sampling methodology (ESM) for 10 days involved 50 young female individuals with EDs and 50 controls. Subclinical psychotic experiences (PE), psychotic symptoms, and disorders were assessed using ESM, Community Assessment of Psychic Experiences, Positive and Negative Syndrome Scale, and Mini-International Neuropsychiatric Interview. ED severity was assessed with the Eating Disorder Examination-Questionnaire. Mixed effects, logistic, and linear regression models were used for the analyses. Results The ED group had significantly more momentary PE (B = 1.57, p <.001), lifetime PE (B = 0.50, p <.001), psychotic symptoms (B = 17.21, p <.001) and lifetime psychotic disorders (B = 2.83, p <.001) than controls. In the ED group, momentary PE were associated with momentary NA, self-esteem, stress, and EDE-Q; lifetime PE were associated with momentary NA, stress, and EDE-Q; and psychotic symptoms were associated with momentary NA. Discussion All levels of psychosis were common in female youth with an ED, and these (subclinical) psychotic phenomena were associated with transdiagnostic factors such as momentary NA, self-esteem, and stress and/or ED severity. The findings have relevance for clinical practice and inform future transdiagnostic studies on the mechanism and treatment of individuals with EDs and (comorbid) psychosis.