Effects of an Internet-based intervention for subthreshold eating disorders: A randomized controlled trial q Corinna Jacobi a, * , Ulrike Völker a , Mickey T. Trockel b , Craig Barr Taylor b a Technische Universität Dresden, Institut für Klinische Psychologie und Psychotherapie Chemnitzer, Straße 46, D 01187 Dresden, Germany b Stanford University School of Medicine, USA article info Article history: Received 1 April 2011 Received in revised form 15 August 2011 Accepted 29 September 2011 Keywords: Subthreshold eating disorders Internet-based prevention Randomized controlled trial abstract Background: Women reporting initial eating disorder (ED) symptoms are at highest risk for the devel- opment of an eating disorder. Preventive interventions should, therefore, be specifically tailored for this subgroup. Aims: To adapt and evaluate the effects of the Internet-based prevention program “Student BodiesÔ” for women with symptoms of disordered eating and/or subthreshold eating disorder (ED) syndromes. Method: 126 women, reporting subthreshold ED symptoms (high weight and shape concerns and below threshold bingeing, purging, chronic dieting or several of these symptoms) were randomly assigned to a Student BodiesÔþ (SBþ) intervention or a wait-list control group and assessed at pre-intervention, post-intervention, and 6-month follow-up. “Student BodiesÔ” was adapted to be suitable for subthreshold EDs. Main outcome measures were attitudes and symptoms of disordered eating. Pre- follow-up data were analyzed by ANCOVAS with mixed effects. Results: At 6-month follow-up, compared to participants in the control group, participants in the intervention group showed significantly greater improvements on ED-related attitudes. Intervention participants also showed 67% (95% CI ¼ 20e87%) greater reductions in combined rates of subjective and objective binges, and 86% (95% CI ¼ 63e95%) greater reduction in purging episodes. Also, the rates of participants abstinent from all symptoms of disordered eating (restrictive eating, binge eating and any compensatory behavior) were significantly higher in the intervention group (45.1% vs. 26.9%). Post-hoc subgroup analyses revealed that for participants with binge eating the effect on EDE-Q scores was larger than in the pure restricting subgroup. Conclusion: The adapted “SBþ” program represents an effective intervention for women with subthreshold EDs of the binge eating subtype. Ó 2011 Elsevier Ltd. All rights reserved. Introduction Eating disorders are serious conditions which can have severe physical and psychological consequences (Roerig, Mitchell, Myers, & Glass, 2002; Taylor et al., 1998). Studies examining long term outcomes of women with clinical EDs have demonstrated that about half of the patients have a rather poor outcome (Zipfel, Löwe, Reas, Deter, & Herzog, 2000). While gains have been made in preventing EDs in young women with high weight and shape concerns and very low levels of compensatory behaviors (e.g., Taylor et al., 2006), many women show more frequent and severe symptoms and behaviors that may progress to full-syndrome eating disorders (Stice, Marti, Spoor, Presnell, & Shaw, 2008). Because rates of women with ED symp- toms are much higher than those of women with full-syndrome EDs, early interventions targeting symptom progression might improve outcomes. Furthermore, recent evidence suggests that a continuum exists between subthreshold EDs and full-syndrome EDs (Gleaves, Brown, & Warren, 2004; Thomas, Vartanian, & Brownell, 2009; Williamson, Gleaves, & Stewart, 2005). While the issue of whether or not ED symptoms should be seen as continuous or dichotomous remains controversial, several authors suggest that lower level behaviors should be addressed because they can be accompanied by similar levels of impairment (Wilson & Sysko, 2009; see also www.dsm5.org). In recent years, considerable progress has been made in iden- tifying risk factors for most EDs, especially bulimia nervosa (BN), binge eating syndromes and eating disorders not otherwise q Presented at the 15th Annual Meeting of the Eating Disorders Research Society in Brooklyn, NY USA, September 24, 2009. * Corresponding author. Tel.: þ49 (0)351 463 38576; fax: þ49 (0)351 463 37208. E-mail address: cjacobi@psychologie.tu-dresden.de (C. Jacobi). Contents lists available at SciVerse ScienceDirect Behaviour Research and Therapy journal homepage: www.elsevier.com/locate/brat 0005-7967/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.brat.2011.09.013 Behaviour Research and Therapy 50 (2012) 93e99