Longitudinal comparison of anorexia nervosa subtypes.

OBJECTIVE: To compare patients with restricting anorexia nervosa (ANR) and binge/purge anorexia nervosa (ANBP) on measures of impulsivity, course, and outcome.

METHODS: One hundred thirty-six treatment-seeking women with AN followed prospectively for 8-12 years were reclassified at intake as 51 ANRs and 85 ANBPs according to the DSM-IV subtyping classification. Lifetime Axis I and Axis II disorders were assessed using structured interviews; follow-up interviews were conducted at 6-12-month intervals to collect weekly data on eating disorder symptomatology.

RESULTS: Women with ANR and ANBP did not differ on history of substance abuse, kleptomania, suicidality, or borderline personality diagnosis at intake, or on rates of recovery, relapse, or mortality. By 8 years of follow-up, 62% of women with ANR crossed over to ANBP prospectively and only 12% of women with AN never reported regular binge/purge behaviors.

CONCLUSIONS: The findings on impulsivity, course, and outcome do not support the current subtyping system. The high crossover rate in our sample from ANR to ANBP suggests that ANR represents a phase in the course of AN rather than a distinct subtype.