Residential eating disorder outcomes associated with screening positive for substance use disorder and borderline personality disorder.

OBJECTIVE: We examined whether eating disorder (ED) outcome trajectories during residential treatment differed for patients screening positive for comorbid borderline personality disorder (BPD) and/or substance use disorders (SUDs) than those who do not.

METHOD: We examined data from patients in a residential ED treatment program. Patients completed validated self-report surveys to screen for SUDs and BPD on admission, and the ED Examination-Questionnaire (EDE-Q) on admission and every 2 weeks until discharge (N = 479 females).

RESULTS: Fifty-four percent screened positive for at least one co-occurring condition. At admission, patients screening positive for SUD and/or BPD had significantly greater eating pathology than patients screening negative for both (t[477] = 8.23, p < .001). Patients screening positive for SUD (independent of BPD screening status) had a significantly faster rate of symptom improvement during the initial 4 weeks than patients screening positive for BPD only and those with no comorbidities.

DISCUSSION: Screening positive for SUD and/or BPD was common in residential ED treatment, and associated with more severe ED symptoms. Screening positive for SUD was associated with faster ED symptom improvement than screening positive for BPD. These findings suggest that intensive ED treatment, even in the absence of intensive SUD treatment, may enhance patient outcomes for those with SUDs.