خودیاری هدایت شونده برای اختلال تغذیه ای: کارآزمایی بالینی تصادفی

Treatment guidelines recommend evidence-based guided self-help (GSH) as the first stage of treatment for bulimia nervosa and binge eating disorder. The current randomised control trial evaluated a cognitive behavioural therapy-based GSH pack, ‘Working to Overcome Eating Difficulties,’ delivered by trained mental health professionals in 6 sessions over 3 months. It was congruent with the transdiagnostic approach and so was intended as suitable for all disordered eating, except severe anorexia nervosa. Eighty one clients were randomly allocated to either a GSH or waiting list condition. Eating disorder psychopathology (EDE-Q), key behavioural features and global distress (CORE) were measured at pre- and post-intervention, and 3- and 6-month follow-up. Results showed significant improvements in eating disorder psychopathology, laxative abuse, exercise behaviours, and global distress, with the GSH condition being superior to the waiting list on all outcomes. Treatment gains were maintained at 3 and 6 months. This study adds to the evidence supporting GSH for disordered eating, including EDNOS. However, further work is needed to establish the factors that contribute to observed therapeutic improvements and determine for whom GSH is most suitable.

Treatment guidelines place cognitive behavioural therapy (CBT) at the heart of the management of bulimia nervosa and some forms of EDNOS (APA, 2006 and NICE, 2004). However, CBT is lengthy, costly, and in relative short supply. In addition, the approach may be unnecessarily intense for some clients with mild to moderate symptoms of disordered eating. Accordingly, following an evidence-based self-help programme is the first step in the treatment of bulimia nervosa recommended by the UK National Institute for Clinical Excellence (NICE, 2004). Self-help has demonstrated comparable results to CBT delivered individually and in a group format (Bailer et al., 2004, Durand and King, 2003, Thiels et al., 1998 and Treasure et al., 1999). Self-help can be used alone (pure self-help, PSH) or with guidance from a mental health professional or layperson (guided self-help, GSH). Looking at relative effectiveness, Carter and Fairburn (1998) compared pure and guided self-help for BED, delivered by non-specialists, to waiting list controls. Remission rates for the groups were 43%, 50% and 8% respectively, with clients in the PSH group more likely to seek additional treatment. Guidance provided by non-specialists for bulimia nervosa was also effective in reducing and maintaining improvements in bingeing, vomiting and eating pathology compared to delayed treatment controls (Banasiak, Paxton, & Hay, 2005). Smaller effect sizes and higher attrition rates were found in a comparable study in Sweden, but conducted without a control group (Ghaderi & Scott, 2003). Studies have compared pure and GSH for bulimia nervosa and binge eating delivered in specialist clinics. Direct comparisons showed both were effective in reducing binge eating and related psychopathology, however GSH achieved higher remission rates and was superior in reducing binge frequency, restraint and interpersonal sensitivity (Loeb, Wilson, Gilbert, & Labouvie, 2000). Palmer, Birchall, McGrain, and Sullivan (2002) investigated two methods of delivering guidance, compared with PSH and waiting list groups. Face-to-face guidance conferred greater treatment benefits to that delivered by telephone, with little support for PSH which failed to differ from waiting list controls (Palmer et al., 2002). Interventions lasted between 12 and 17 weeks, and the amount and standard of guidance varied, along with completion rates (58–78%). Overall, evidence shows GSH to have a range of benefits compared with PSH, although compared solely on primary outcomes such as binge episodes there is less difference in effectiveness (Perkins, Murphy, Schmidt, & Williams, 2006). In addition, while intervention effects are modest in size, the evidence may be limited by the differences in guidance and the frequent absence of true control groups. Furthermore, the extent to which such interventions may be useful for mixed patterns of disordered eating, such as EDNOS, is largely unknown. The present study investigated the effectiveness of a new GSH intervention, ‘Working to Overcome Eating Difficulties’. The intervention comprised three main elements that characterise its novelty and distinguish it from previous GSH resources. First, it was a CBT-based written manual congruent with a transdiagnostic perspective, in which all eating disorders share a common core psychopathology and network of inter-related maintaining mechanisms (Fairburn et al., 2003 and Fairburn and Harrison, 2003). Accordingly, the manual included all common features of eating disorders, not just bulimic disorders, along with sub-sections specifically focussed around the four additional maintaining mechanisms outlined by Fairburn – perfectionism, low self-esteem, mood intolerance and interpersonal difficulties (Fairburn et al., 2003). For example, it included mindful breathing and eating exercises aimed at encouraging awareness and acceptance of bodily sensations and adverse mood states, which enable individuals to make adaptive choices about responding, rather than reacting to aversive experiences. Mindfulness has shown to be effective in reducing binge eating and managing emotional distress in both bulimia nervosa and BED (Baer et al., 2005, Leahey et al., 2008 and Proulx, 2008). Also in line with the transdiagnostic approach, there was little focus on specific eating disorder diagnosis. Rather, the treatment content and goals were dictated by individuals’ particular psychopathological features and maintaining factors, formulated in the early sessions and revisited throughout. With this in mind, the current manual was designed to be applicable to a range of disordered eating (including EDNOS). Second, the intervention was guided by a number of non-eating disorder specialist mental health professionals in primary and secondary care settings. Much of the existing evidence on effectiveness of GSH has been conducted either in eating disorder specialist settings or delivered by specialists. And most have only assessed the effectiveness of delivery by a small number of therapists, which tells us little about its potential to be utilised across a range of services, by a range of professionals. Third, pre-intervention mandatory training and intervention-concurrent support was provided for those acting as guides. In some existing GSH programs, guidance was provided by trained therapists such as clinical psychologists, but few describe any GSH-specific training or supervision (Grilo and Masheb, 2005, Loeb et al., 2000 and Palmer et al., 2002). Those that do, appear to have relied on instructions provided in a therapist’s manual (Carter & Fairburn, 1998), with the exception of Ghaderi and Scott (2003) who describe reviewing and discussing the manual with the students who were to provide guidance. The latter two features are concerned with utility outside of specialist settings. The intervention therefore represented a low intensity approach, directed at all disordered eating, that was delivered by a range of non-specialists who were trained and supported in its delivery. The study aim was to evaluate the intervention in a randomised controlled trial (RCT) with 6-month follow-up. Accordingly, it was hypothesised that the GSH intervention would lead to maintained reductions in eating disorder psychopathology, key behavioural symptoms, and global distress in clients with a range of disordered eating problems, including EDNOS.