Anorexia nervosa has, of all eating disorders, the highest chronicity and mortality rate in young women and is probably the psychiatric disorder with the highest mortality. In comparison to bulimia nervosa and binge eating disorder, few controlled psychotherapy trials for anorexia nervosa have been published, and surprisingly there is hardly any study on relapse prevention or post-hospitalization treatment of anorexia nervosa (Pike, Walsh, Vitousek, Wilson, & Bauer, 2003). Extremely high drop-out rates in clinical trials for anorexia nervosa (Halmi et al., 2005) have constituted one major problem for psychotherapy studies.
Current technological developments of communication media make new approaches to diagnostic and therapeutic interactions with persons at risk and patients possible. The internet-based primary prevention of various disorders for persons at risk and the development of new forms of therapy and relapse prevention for patients with a variety of medical or psychological illnesses represent important new developments. Thus, controlled internet-based studies for primary, secondary or tertiary prevention have been reported for diabetes mellitus (Bastelaar, Pouwer, Cuijpers, Riper, & Snoek, 2011), cardiological disorders (Kuhl, Sears, & Conti, 2006), and asthma (Runge, Lecheler, Horn, Tews, & Schaefer, 2006). Other prevention programs focused on the promotion of regular physical activity to improve health (De Bourdeaudhuij et al., 2010) or management of work-related stress (Billings, Cook, Hendrickson, & Dove, 2008).
Concerning internet-based forms of psychotherapy in a broader sense, more than 100 randomized controlled studies exist, and additionally some systematic reviews, and meta-analyses such as the one by Spek et al. (2007) concerning depression and anxiety disorders, the one by Cuijpers et al. (2009) concerning anxiety disorders and the one by Barak, Hen, Boniel-Nissim, and Shapira (2008) concerning the effectiveness of internet-based psychological interventions in general. More studies concerning internet-based psychotherapy have been conducted in the area of depression (e.g. Gerhards et al., 2010) and anxiety disorders (e.g. Rollman et al., 2005) including panic disorder, various phobias and posttraumatic stress disorder (e.g. Lange et al., 2003). For somatic as well as psychiatric disorders, internet-based interventions have been shown to be promising for the reduction of symptoms and have been shown to affect reference points for illness such as sick days, number of medical consultations, and strategies for coping with illness. Applying therapist-guided internet chat groups as relapse prevention after inpatient psychotherapy for a variety of psychosomatic disorders (e.g. mood disorder, personality disorder, somatoform disorders) resulted in a lower rate of relapse and a longer survival time until relapse (Bauer, Wolf, Haug, & Kordy, 2011). Concerning eating disorders, only a rather limited number of studies has been published. In the last two decades, there has been a larger number of controlled studies evaluating the effect of manualized and guided self-help for bulimia nervosa and some studies for binge eating disorder (Williams, Aubin, Cottrell, & Harkin, 1998). This development was a good basis for developing internet-based interventions for bulimia nervosa, and the results for controlled studies on this issue have been published by Carrard et al., 2006, Shapiro et al., 2007, Schmidt et al., 2008 and Fernandez-Aranda et al., 2008, and Sánchez-Ortiz et al. (2011). In parallel to these developments, there have been studies addressing not patients with an eating disorder but persons in the community or students at risk for eating disorder with internet-based programs (Celio et al., 2000, Jacobi et al., 2007, Paxton et al., 2007, Taylor et al., 2006 and Zabinski et al., 2003). Practically all interventions that have been evaluated for eating disorders are based on manuals of cognitive-behavior therapy. Internet-based therapies have frequently been supplemented by text messages and e-mail functions (Ljotsson et al., 2007 and Shapiro et al., 2007). For internet-based interventions, one issue pertains to their effectiveness and efficacy and another one to cost effectiveness. Internet-based programs can reach a large number of patients or persons at risk at considerably lower cost than traditional approaches. We estimate that a trained therapist needs to allot about 8 h of weekly time in order to take care of 100 active users of the program the way we designed it. Moreover, such programs can reach individuals who, due to a lack of motivation or large geographical distance, would otherwise not take part in any intervention.
The aim of our study, which to our knowledge is the first randomized controlled study of internet-based relapse prevention for anorexia nervosa, was to evaluate the efficacy of a 9-month internet-based intervention program for AN, compared to a group of AN patients receiving treatment as usual (TAU) following discharge from inpatient therapy. This RCT was registered with Current Controlled Trials (ISRCTN20173615) and in the ‘Deutsches Register Klinischer Studien’ (DRKS00000081; German Registry of Clinical Trials).
