The validity and utility of subtyping bulimia nervosa.
OBJECTIVE
To review the evidence for the validity and utility of subtyping bulimia nervosa (BN) into a purging (BN-P) and a nonpurging subtype (BN-NP), and of distinguishing BN-NP from binge eating disorder (BED), by comparing course, complications, and treatment.


METHODS
A literature search of psychiatry databases for studies published in peer-reviewed journals that used the DSM-definitions of BN and BED, and included both individuals with BN-NP and individuals with BN-P and/or BED.


RESULTS
Twenty-three studies compared individuals with BN-NP (N = 671) to individuals with BN-P (N = 1795) and/or individuals with BED (N = 1921), two of which reported on course, 12 on comorbidity and none on treatment response-the indicators for validity and clinical utility. The differences found were mainly quantitative rather than qualitative, suggesting a gradual difference in severity from BN-P (most severe) through BN-NP to BED (least severe).


CONCLUSIONS
None of the comparisons provided convincing evidence for the validity or utility of the BN-NP diagnosis. Three options for the position of BN-NP in DSM-V were suggested: (1) maintaining the BN-NP subtype, (2) dropping nonpurging compensatory behavior as a criterion for BN, so that individuals currently designated as having BN-NP would be designated as having BED, and (3) including BN-NP in a broad BN category.
van Hoeken
Daphne
D
Department of Research, Parnassia Bavo Psychiatric Institute, The Hague, The Netherlands.
Veling
Wim
W
Sinke
Sjoukje
S
Mitchell
James E
JE
Hoek
Hans W
HW
D002032:Bulimia / Q000145:classification / Q000175:diagnosis; D052018:Bulimia Nervosa / Q000145:classification* / Q000175:diagnosis; D039721:Diagnostic and Statistical Manual of Mental Disorders; D006801:Humans; D014839:Vomiting / Q000523:psychology