Original Articles

Patterns of co-morbidity of eating disorders and substance use in Swedish females

T. L. Root^a1, E. M. Pisetsky^a1, L. Thornton^a1, P. Lichtenstein^a2, N. L. Pedersen^a2a3 and C. M. Bulik^a1a4 c1

^a1 Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA

^a2 Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden

^a3 Department of Psychology, University of Southern California, Los Angeles, CA, USA

^a4 Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA

Abstract

Background Little is known about the association of eating disorder subtypes across multiple categories of substance use in population-based samples. We examined the association between eating disorders and substance use in a large population-based sample.

Method Female participants (n=13 297) were from the Swedish Twin Registry [Lichtenstein et al., Twin Research and Human Genetics (2006) 9, 875–882]. Substance use was examined in four defined groups – (1) anorexia nervosa (AN); (2) bulimia nervosa (BN); (3) AN and BN (ANBN); and (4) binge eating disorder (BED) as well as a referent group without eating disorder (no ED). Secondary analyses examined differences between restricting AN (RAN) and binge and/or purge AN (ANBP).

Results In general, eating disorders were associated with greater substance use relative to the referent. The AN group had significantly increased odds for all illicit drugs. Significant differences emerged across the RAN and ANBP groups for alcohol abuse/dependence, diet pills, stimulants, and polysubstance use with greater use in the ANBP group. Across eating disorder groups, (1) the BN and ANBN groups were more likely to report alcohol abuse/dependence relative to the AN group, (2) the ANBN group was more likely to report diet pill use relative to the AN, BN and BED groups, and (3) the BN group was more likely to report diet pill use relative to the no ED, AN and BED groups.

Conclusions Eating disorders are associated with a range of substance use behaviors. Improved understanding of how they mutually influence risk could enhance understanding of etiology and prevention.

(Received August 22 2008)

(Revised February 16 2009)

(Accepted February 21 2009)

(Online publication April 20 2009)

Key Words:

• Alcohol;
• anorexia nervosa;
• binge-eating disorders;
• bulimia nervosa;
• tobacco

Correspondence:

^c1 Address for correspondence: C. M. Bulik, Ph.D., Department of Psychiatry, University of North Carolina at Chapel Hill, 101 Manning Drive, CB #7160, Chapel Hill, NC 27599-7160, USA. (Email: cbulik@med.unc.edu)