Where does purging disorder lie on the symptomatologic and personality continuum when compared to other eating disorder subtypes? Implications for the DSM.

Objectives: To assess the clinical significance and distinctiveness of purging disorder (PD) from other eating disorder (ED) diagnoses.

Method: Participants included 3127 women consecutively admitted to an ED treatment centre (246 PD, 465 anorexia nervosa restrictive [AN-R], 327 AN-binge purging [AN-BP], 1436 bulimia nervosa [BN], 360 binge eating disorder [BED], 177 atypical AN and 116 unspecified feeding or eating disorder [UFED]) who were diagnosed according to DSM-5 criteria. Additionally, 822 control participants were recruited from the community. All participants completed measures assessing ED symptoms (EDI-2), general psychopathology (SCL-90-R) and personality (TCI-R).

Results: Patients with PD, when compared to controls, scored significantly higher on the EDI-2 and SCL-90-R, and most TCI-R dimensions. Most of the significant differences between PD and the other ED diagnoses emerged between PD and AN-R, followed by Atypical-AN, UFED, AN-BP and BED, with patients with PD typically reporting higher scores on the EDI-2 and SCL-90-R subscales. Significant differences between PD and BN were also present, but to a lesser extent. The findings for personality varied amongst the different ED diagnoses.

Conclusions: PD is a clinically significant disorder, which seems to be more similar to BN than it is to AN and the other ED subtypes.