Distinguishing delusional beliefs from overvalued ideas in Anorexia Nervosa: An exploratory pilot study

Abstract

Background Characterised by the belief that more weight needs to be lost—despite emaciation, failing organs, medical instability and prospect of death—Anorexia Nervosa (AN) is a condition in which irrational, and highly-skewed, beliefs can be of delusional intensity. However, the nexus between delusion and rational awareness and how this is related to body image acceptance and perception has yet to be examined in AN. The current study aims to investigate the relationship between body dissatisfaction and beliefs of delusional intensity in an adult AN inpatient sample. Methods Twenty-one adults (n(women) = 20; n(men) = 1), with a mean age of 27 years old (SD = 10), presenting for inpatient treatment for AN (ranging in severity from mild to severe; M(Body Mass Index) = 17 kg/m2; M(Length of Stay) = 22 days) participated in the study. Participants’ dominant beliefs (related to AN) and level of insight (delusional; overvalued idea; or fair insight) were measured using either the Brown Assessment of Beliefs Scale (BABS) or the Nepean Beliefs Scale (NBS). The degree of body dissatisfaction was determined by examining the discrepancy between “perceived” and “ideal” body perception. To determine subjective and objective beliefs both the Contour Drawing Rating Scale (subjective) and computerised Body Image Assessment Software (objective) were used. Results Almost one quarter (23.7%; n = 5) of participants appeared to have beliefs of delusional intensity related to their body shape (M = 27.4; SD = 23.03). Although a positive linear trend was indicated, there were no significant differences in body dissatisfaction scores between level-of-insight. Individuals whose belief was categorised as delusional were more likely to hold a negative affective body image state based on their ratings on the body image state survey when compared to the group who had good/fair insight (95% CI [0.53, 18.19]; p = 0.03). Conclusions The current exploratory pilot study concurs with others in the published literature that demonstrate that approximately 25 percent of participants with AN may have delusional ideas. The implications for treatment in similar samples warrant attention. Future research should also seek to understand the clinical significance of this delusional categorisation, the benefits of its utility in this population, and its relation to the severity of AN or stage of illness.

Reliability and validity of the Nepean Beliefs Scale for delusions and overvalued ideas in chronic schizophrenia: analysis of a preliminary pilot study

“…The mean NBS total score in acute hospitalized psychosis in Rajendran et al ( 5 ) was 15.99, and in anorexia nervosa in Barton et al ( 4 ) was 14.30; therefore, the present mean of 14.93 is reasonable compared to these previous studies. In Barton et al ( 4 ), six participants had “good/fair insight,” 10 participants had “overvalued idea,” and five participants were “delusional,” whereas in the present study, in order, four, nine, and 15, and the proportion of “delusional” among the number of participants was high. This also seems to be a reasonable result given the differences in disorders.…”

“…Following the findings of Barton et al ( 4 ), the NBS total score was classified into three levels: 0–10: “good/fair insight,” 11–15: “overvalued idea,” and 16–20: “delusional,” with four respondents having “good/fair insight,” nine having “overvalued idea,” and 15 having “delusional.”…”

“…Although initially developed to examine obsessions, NBS has been suggested to be reliable and valid when used to assess overvalued ideas in anorexia nervosa ( 4 ) and delusions and pathological beliefs in acute psychosis ( 5 ). In particular, the subjects in Rajendran et al’s study were diverse, including those with schizophrenia, schizoaffective disorder, bipolar affective disorder, delusional disorder, substance/drug-induced psychotic disorder, and short-term psychotic disorder.…”

Delusions in Anorexia Nervosa

“…Several studies have attempted to quantitively assess these differences in belief strength by employing the BABS, concluding that while some patients exhibit strong enough conviction in their body size beliefs to be considered delusional, most do not hold their beliefs with delusional strength, instead being classified as holding overvalued ideas, or exhibiting good insight (Barton et al, 2022;De Young et al, 2022;Hartmann, Thomas, Wilson, & Wilhelm, 2013;Kambanis et al, 2022;Konstantakopoulos, Ioannidi, Patrikelis, & Gonidakis, 2020;Konstantakopoulos et al, 2012;G. McKenna, Fox, & Haddock, 2014;Mountjoy, Farhall, & Rossell, 2014;Şenay & Yücel, 2022;Steinglass, Eisen, Attia, Mayer, & Walsh, 2007).…”

“…(De Young et al, 21;Kambanis et al, 2022). Unfortunately, some studies do not report the prompt they used (Hartmann et al, 2013;McKenna et al 2014;Barton et al, 2022) and only three report the kinds of belief-content that were studied. 3 The lack of standardisation in the prompts used when administering the BABS has lead to mixed results, which obscure the true nature of belief strength associated with AN.…”