Psychological Medicine

The epidemiology and classification of bulimia nervosa

P. F. SULLIVAN a1c1, C. M. BULIK a1 and K. S. KENDLER a1
a1 From the Department of Psychiatry, Virginia Commonwealth University/Medical College of Virginia and Virginia Institute for Psychiatric and Behavioral Genetics, Richmond, VA, USA


Background. We sought to determine whether there was empirical support for the diagnostic thresholds of DSM-IV bulimia nervosa (BN) and whether an empirically derived typology resembled the diagnostic categories of DSM-IV.

Methods. Detailed information about bulimic behaviours were assessed via personal interview in a population-based sample of 1897 Caucasian female twins. We assessed the lifetime prevalence of the component bulimic behaviours and DSM-IV and DSM-III-R BN. Latent class analysis of nine separate bulimic symptoms was used to develop an empirical typology of bulimic behaviour.

Results. Although the lifetime prevalences of bingeing (23·6%) and vomiting (4·8%) were relatively common, DSM-IV BN was distinctly uncommon (0·5%). The criterion that specified the frequency and duration of bingeing and vomiting was an important limiting condition. Analysis of alternative thresholds found little support for the DSM-IV thresholds requiring an average of twice per week for 3 months. Latent class analysis yielded an interpretable four class solution that had little overlap with the DSM-IV typology.

Conclusions. As in other studies of unselected samples of women, the lifetime presence of bulimic behaviours are relatively high. Our results suggest that the DSM-IV approach to categorizing bulimic behaviour inadequately captures the spectrum of lifetime bulimic behaviours in the general population.

c1 Address for correspondence: Dr Patrick F. Sullivan, Department of Psychiatry, Virginia Institute for Psychiatric and Behavioral Genetics, PO Box 980126, Richmond, VA 23298-0126, USA.