Is orthorexia nervosa a feature of obsessive–compulsive disorder? A multicentric, controlled study

Purpose: The term orthorexia nervosa (ON) was coined to describe altered thoughts and behaviours related to healthy eating. The prevalence of ON was found to scale up to almost 90% among high-risk populations (ballet dancers, athletes, and health workers). ON seem to share psychopathological aspects with both Eating Disorders (ED) and Obsessive–Compulsive Disorder (OCD). The aim of the study was to analyse the frequency and intensity of ON symptoms among subjects diagnosed with OCD, hypothesising that they would be higher than in two control groups (subjects with anxiety-depressive disorders and general population). Methods: We conducted a multi-centre, observational, controlled study. Subjects filled in a socio-demographic questionnaire including questions related to life-style and two psychometric instruments: ORTO-15, for ON symptoms, and OCI-R, for OCD symptoms. Post hoc analysis of the dataset was performed using the revised version of ORTO-15, the ORTO-R. Results: In the final sample of 328 subjects, the overall prevalence of ORTO-15-ON was 59.5%, mean score 37.9 ± 4.2. The mean score at the ORTO-R was 16.6 ± 4.6. No statistically significant differences were found in the prevalence of ON or in the mean ORTO-15 score among OCD patients and the two control groups, and this was confirmed by the multiple regression analysis. At the ORTO-R re-scoring, OCD patients scored significantly lower than the two clinical subgroups (p =.0005) and a lower ORTO-R score was associated to positivity at the OCI-R, confirming the initial hypothesis of the study. Conclusions: ON symptoms do seem to be more prevalent among subjects suffering from OCD. The psychometric properties of tools available to calculate ON symptoms, namely ORTO-15 vs. ORTO-R, play a relevant role in explaining such finding. ORTO-R seems to be a valid alternative able to overcome such difficulties, though further studies are needed to confirm this.