Themes and prevalence of ideas/delusions of reference in early psychosis

Abstract

Background: Recent emphasis on a symptom dimension and continuum approach in understanding psychosis has resulted in a need for more refined description of common psychotic symptoms. While Ideas/delusions of reference (I/DOR) were reported in two-thirds of schizophrenic patients, not much is known beyond this earlier observation. This descriptive study provides more details.

Methods: Structured interviews were conducted in a consecutive sample of 137 outpatients with early psychosis by trained raters using an I/DOR scale validated in Hong Kong Chinese. General symptoms were rated by patients' psychiatrists using Positive and Negative Syndrome Scale (PANSS), Scale for the Assessment of Positive Symptoms (SAPS), Scale for the Assessment of Negative Symptoms (SANS), Calgary Depression Scale for Schizophrenia and Scale to Assess Unawareness of Mental Disorder.

Results: During the study period, I/DOR was present in 43 cases and subsided in 47, giving a point prevalence of 31.4% and a prevalence of 65.7%. It is equally represented in both sexes, across diagnoses and sociodemographic factors. I/DOR is associated with auditory hallucination, persecutory delusions and circumstantiality in SAPS (r = 0.39, 0.28 and 0.34), impersistence at work/school and inability to feel intimacy and closeness in SANS (r = 0.26 and 0.25), and depression (r = 0.24; all p < 0.01). Insight was not affected. The most commonly reported themes were “being talked/laughed at” (73% of I/DOR cases), “being followed” (30%), “being gazed upon” (29%) and “being depicted in mass media” (28%). Of note, 17% (18/106) of remitted patients (defined using PANSS criteria) were currently experiencing IOR.

Conclusions: Our study confirmed previous prevalence findings. I/DOR is a common experience in early psychosis, unexplained by individual patient characteristics. It covariates with a number of positive and negative symptoms, but does not affect insight. Patterns of association between individual I/DOR themes and psychotic symptoms are explored. This study suggests possible directions for future pathogenesis studies. Implications of subthreshold I/DOR in remitted patients despite otherwise adequate disease control also call for attention.