Marmorstein, N.R., Von Ranson, K.M., Iacono, W.G. & Succop, P.A. (2007). Longitudinal Associations Between Externalizing Behavior and Dysfunctional Eating Attitudes and Behaviors: A Community-Based Study. Journal of Clinical Child and Adolescent Psychology, 36, 87-94.
This study investigated longitudinal associations between externalizing behavior and dysfunctional eating attitudes and behaviors. Participants were girls drawn from the community-based Minnesota Twin Family Study and assessed at ages 11, 14, and 17. Cross-sectional correlations indicated that the strength of the associations between externalizing behavior and dysfunctional eating attitudes and behaviors increased over time. Mixed-model analyses indicated that earlier externalizing behavior predicted increases in weight preoccupation, body dissatisfaction, and use of inappropriate compensatory behaviors. Earlier use of inappropriate compensatory behaviors predicted increases in externalizing behavior.

Keel, P.K., Klump, K.L., Miller, K.B., McGue, M. & Iacono, W.G. (2005). Shared Transmission of Eating Disorders and Anxiety Disorders. International Journal of Eating Disorders, 38, 99-105.
ABSTRACT
Objective: Eating disorders have high comorbidity with mood, anxiety, and substance use disorders. Using twins from the population-based Minnesota Twin Family Study (MTFS), we examined comorbidity and shared transmission between eating pathology and these disorders.
Method: Female twins (N ¼ 672), ages 16–18 years, completed structured clinical interviews assessing anorexia nervosa and bulimia nervosa (as described in the 4th ed. of the Diagnostic and Statistical Manual of Mental Disorders [DSM-IV; American Psychiatric Association, 1994]), as well as mood, anxiety, and substance use disorders (as described in the 3rd Rev. ed. of the Diagnostic and Statistical Manual of Mental Disorders [DSM-III-R]). Shared transmission was examined using a discordant monozygotic (MZ) twin design.
Results: Significant comorbidity was found between eating disorders and major depression, anxiety disorders, and nicotine dependence. Within MZ twin pairs discordant for eating disorders (n ¼ 14), non–eating-disordered cotwins demonstrated increased risk for anxiety disorders compared with controls. Similarly, within MZ twin pairs discordant for anxiety disorders (n ¼ 52), non–anxiety-disordered cotwins demonstrated increased risk for eating disorders compared with controls.
Discussion: Findings support shared transmission between eating disorders and anxiety disorders. However, the nature of this shared diathesis remains unknown.

Perkins, P.S., Klump, K.L., Iacono, W.G. & McGue, M. (2005). Personality Traits In Women with Anorexia Nervosa: Evidence for a Treatment Seeking Bias? International Journal of Eating Disorders, 37, 32-37.
Objective: Several personality traits have been associated with anorexia nervosa
(AN) in treatment-seeking samples of patients. The current study used a population-based sample to compare the personality characteristics of women with AN who sought treatment versus those who did not.
Method: Participants included 27 (14 treatment-seekers, 13 non-treatmentseekers)women with threshold or subthreshold AN and 273 (64 treatment seekers, 209 non-treatment seekers) comparison women from the Minnesota Twin Family Study. Personality was assessed with the higher-order factors and primary scales of the Multidimensional Personality Questionnaire (MPQ).
Results: Non–treatment-seeking women showed lower levels of negative emotionality, stress reaction, and alienation than treatment-seeking women.
Discussion: These results suggest that personality deviations may be overestimated in treatment-seeking samples.
©2004 by Wiley Periodicals, Inc.
(Int J Eat Disord 2005; 37:32–37)

Von Ranson, K.M., Klump, K.L., Iacono, W.G. & McGue, M (2005). The Minnesota Eating Behavior Survey: A brief measure of disordered eating attitudes and behaviors. Eating Behaviors, 6, 373-392.
This article describes details of the development and psychometric characteristics of a brief self-report inventory for assessing attitudes and behaviors symptomatic of eating disorders that is currently in use in a longitudinal study of over 700 families with 11-year-old or 17-year-old twin girls. The Minnesota Eating Behavior Survey (MEBS), formerly the Minnesota Eating Disorder Inventory, is a 30-item measure developed for use with children as young as 10 years as well as adults. An examination of the MEBS’s psychometric properties in a large, community sample of girls, women, and men demonstrated good factor congruence, internal consistency reliability, three-year stability, as well as evidence of concurrent and criterion validity. This questionnaire has promise as a screening and assessment measure for eating disturbance in cross-sectional and longitudinal research involving individuals of a wide range of ages.

Klump, K.L., McGue, M., & Iacono, W.G. (2003). Differential Heritability of Eating Attitudes and Behaviors in Prepuberbertal and Pubertal Twins. International Journal of Eating Disorders, 33, 287-292.
Objective: Differential heritability of eating pathology in prepubertal, pubertal, and 17-year-old twins was examined using a population-based twin sample.
Method: Participants included 530 11-year-old (452 prepubertal, 78 pubertal twins) and 602 17-year-old female twins from the Minnesota Twin Family Study. Puberty was assessed with the Pubertal Development Scale, and general eating pathology was assessed with the total score from the Minnesota Eating Disorders Inventory (M-EDI). Klump,

K.L., Miller, K.B., Keel, P.K., McGue, M., & Iacono, W.G. (2000)."A population based twin study of anorexia and bulimia nervosa: Heritability and shared transmission with anxiety disorders."Psychological Medicine, in press.
Prior studies have found evidence for genetic influences on eating disorders, as well as evidence that adolescents with eating disorders are at increased risk for mood, anxiety, alcohol use, and nicotine use disorders.  This study, based on 16-, 17-, and 18-year-old MTFS participants, provides further support for these findings.

Von Ranson, K.M., Iacono, W.G., & McGue, M. (2001). "Disordered eating and substance use in an epidemiological sample: I. Associations within individuals." International Journal of Eating Disorders, in press.
This study made use of MTFS 17-year-old girls and the mothers of all the MTFS participants to investigate the relationship between disordered eating and substance use.  Substance use was modestly associated with restrictive as well as bulimic behaviors, and there were no significant differences in associations within substance use classes.  Some have suggested that bulimia is an example of an addictive pattern of behavior, but this study provides no evidence for this.

Klump, K.L., Miller, K.B., Keel, P.K., McGue, M., & Iacono, W.G. (2001)."Genetic and environmental influences on anorexia nervosa syndromes in a population-based twin sample." Psychological Medicine, 31, 737-740.
This study made use of MTFS 17-year-olds to measure the genetic and environmental influences on the incidence of anorexia.  In this sample, 74% of the variance was genetic in origin, and 26% was unshared environmental.  These results are comparable to those from other samples.

Klump, K. L., M. McGue, et al. (2000). "Age differences in genetic and environmental influences on eating attitudes and behaviors in preadolescent and adolescent female twins." Journal of Abnormal Psychology 109(2): 239-251.
This study made use of MTFS 11-year-old and 17-year-old females to examine age differences in genetic and environmental influences on eating disordered behaviors and attitudes and associations between body mass index and eating disorders.  Shared environmental influences on both the eating disorders and their associations with body mass index were more important for 11-year-olds, while genetic influences were more important for 17-year-olds.  Still, for the older twins, most of the genetic influences on eating disorders were independent of the genetic associations with body mass index.

Klump, K. L., A. Holly, et al. (2000). "Physical similarity and twin resemblance for eating attitudes and behaviors: A test of the equal environments assumption." Behavior Genetics 30(1): 51-58.
Twin studies are based on the assumption that identical and fraternal twin pairs share equally similar environments.  This is usually interpreted to mean that the greater physical similarity of identical twins does not cause them to share more common experiences.  This study made use of MTFS females to test this assumption with respect to eating disordered behaviors and attitudes, with the result that physical similarity was not related to similarity of eating behaviors and attitudes.

Sherman, D. K., W. G. Iacono, & Donnelly, J.M. (1995). "Development and validation of body rating scales for adolescent females." International Journal of Eating Disorders 18(4): 327-33.
This study made use of MTFS 11-year-olds and 17-year-olds to develop practical body rating scales for use in body image research with children and adolescents.