Introduction
This essay will undertake a comprehensive review of the available evidence concerning the effectiveness of enhanced cognitive-behavioral therapy (CBT-E), a transdiagnostic therapeutic approach tailored for individuals with eating disorders (EDs) (Fairburn, Cooper, & Shafran, 2008). According to the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), EDs are characterized as “persistent disturbances in eating or eating-related behaviors resulting in altered food consumption or absorption, significantly impairing physical health or psychosocial functioning” (American Psychiatric Association [APA], 2013, p. 329). The most frequently diagnosed EDs include anorexia nervosa (AN), typified by body dysmorphia, restricted caloric intake, and severe weight loss; bulimia nervosa (BN), marked by episodes of binge-eating followed by compensatory behaviors aimed at preventing weight gain; and binge-eating disorder (BED), characterized by recurrent episodes of uncontrolled consumption of large quantities of food within two hours (APA, 2013). A novel addition to DSM-5 is avoidant restrictive food intake disorder (ARFID), which involves a limited intake of solid foods leading to nutritional deficiencies (APA, 2013). Individuals who do not meet all the criteria for the disorders above but experience significant distress or impairment may receive a diagnosis of ED not otherwise specified (ED-NOS) (APA, 2013); typically, this is treated according to the disorder that most closely aligns with the individual’s ED presentation (Fairburn et al., 2008).
Enhanced Cognitive-Behavioral Therapy (CBT-E):
Before the development of CBT-E, previous guidelines recommended distinct treatment approaches for each type of eating disorder: refeeding combined with psychosocial interventions for AN, CBT for BN (CBT-BN), and CBT for BED (CBT-BED) (National Collaborating Centre for Mental Health, 2004). Fairburn, Cooper, and Shafran (2003) proposed a transdiagnostic perspective for understanding and treating EDs as common mechanisms underpinned their behaviors. Building on this, Fairburn et al. (2008) introduced the concept of ‘enhanced’ cognitive-behavioral therapy (CBT-E), designed to address any form of eating disorder. It can be administered in a focused form (CBT-Ef), targeting the specific pathology of the ED, or a broad form (CBT-Eb), which also addresses psychosocial issues that often contribute to or maintain ED pathology (Fairburn et al., 2008). The National Institute for Health and Care Excellence (NICE, 2017) guidelines refer to the focused form as ‘ED-focused CBT’ (CBT-ED).
Grounded in transdiagnostic theory, CBT-E is intended for individual adults with clinically significant EDs amenable to outpatient treatment (Murphy, Straebler, Cooper, & Fairburn, 2010). For patients with a body mass index (BMI) exceeding 17.5, treatment typically involves 20 sessions over 20 weeks, while those with a BMI below 17.5 receive an extended treatment of 40 sessions over 40 weeks. The default version is employed for most patients, with the broad version reserved for individuals exhibiting marked clinical perfectionism, core low self-esteem, or interpersonal difficulties (Murphy et al., 2010). Following a collaborative assessment that includes a personalized formulation or case conceptualization, treatment begins with stage one, encompassing collaborative weekly weigh-ins, self-monitoring, psychoeducation, and the establishment of regular eating habits. Stage two addresses ongoing difficulties and barriers in a transitional phase. Stage three, the core treatment phase, targets key cognitive processes maintaining the disorder, such as overvaluation of shape and weight, dietary rules, and event-related changes in eating behaviors. For CBT-Eb, clinical perfectionism, low self-esteem, and interpersonal issues are also addressed. The final stage, stage four, involves planning to maintain progress. For underweight patients, modifications are made to address motivation, restore average body weight through a nutritional program, and, if appropriate, involve other family members in the treatment process.
An initial evaluation of CBT-Ef and CBT-Eb involved patients with a body mass index over 17.5 diagnosed with either BN, BED, or ED-NOS; individuals with AN were excluded from this study (Fairburn et al., 2009). Participants were randomly assigned to one of the two forms of CBT, either beginning treatment immediately or after an 8-week waiting period. Those on the waiting list displayed no improvement in their symptoms. In contrast, approximately half of those receiving either treatment exhibited a reduction in symptom severity, bringing them within one standard deviation of a community sample. Planned exploratory analysis revealed that individuals with more complex psychopathology tended to respond better to CBT-Eb, while those with simpler psychopathology showed better responses to CBT-Ef. Consequently, it was recommended that the focused form of treatment be employed for most ED patients, with the broader form reserved for those grappling with more intricate psychosocial challenges. In another study comparing the effectiveness of CBT-Ef with interpersonal psychotherapy (IPT) among patients with BN, BED, or ED-NOS, significantly more participants achieved remission after undergoing CBT-Ef as opposed to IPT (Fairburn et al., 2015).
A systematic review of randomized controlled trials (RCTs) evaluating the efficacy of available treatments for EDs, conducted by Hay (2013), consistently found that CBT was the most effective treatment for BN. However, RCTs specifically targeting AN are scarce, and none have been conducted for ARFID. Notably, Hay (2013) identified two studies suggesting CBT might be less effective than other established treatments, although these RCTs did not involve CBT-E. Research on AN typically faces challenges such as small sample sizes and high attrition rates, attributed to difficulties in recruiting participants, substantial dropout rates, low motivation for change, and AN’s resistance to treatment (Fairburn et al., 2013; Murphy et al., 2010). Given the insufficient robust evidence for AN treatments, smaller studies have been conducted to justify larger RCTs (Fairburn et al., 2013).
Preliminary findings from a three-site study that employed CBT-E to treat outpatients with AN and a BMI ranging from 15.0 to 17.5 revealed that 60 percent of participants completed the treatment. Among those who completed the program, 60 percent achieved favorable outcomes with a low relapse rate (Fairburn, 2009). In the first open trial that included all EDs, including AN, two-thirds of the participants who completed the treatment achieved full remission, accounting for 40 percent of the sample (Byrne, Fursland, Allen, & Watson, 2011). Further investigation into the high dropout rates in that study identified three predictors: extended wait-list times, a history of meager weight, and avoidance of effect (Carter et al., 2012). Therefore, the treatment proved effective for most participants who completed the program, with the primary challenge being the motivation to continue.
The Anorexia Nervosa Treatment of Outpatients (ANTOP), a large multicenter RCT comparing the efficacy of 10 months of CBT-E, focal psychodynamic therapy (FPT), and optimized treatment as usual (outpatient psychotherapy plus structured care from a doctor) in 727 adults with AN, demonstrated that all three treatments were equally effective in normalizing BMI (Zipfel et al., 2014). However, FPT exhibited superior recovery rates after a 12-month follow-up, while CBT-E resulted in more rapid weight gain and improved ED psychopathology. In a two-country study involving 99 adults with AN who completed 40 weeks of CBT-E, all participants who were able to complete the treatment, comprising 64 percent of the group, experienced significant weight and BMI increases along with improvements in ED features (Fairburn et al., 2013). An initial study with 49 patients also indicated that CBT-E could serve as an alternative to family-based therapy for adolescents with AN, with two-thirds of participants completing the program, resulting in substantial weight gain and reduced ED pathology (Dalle Grave, Calugi, Doll & Fairburn, 2013). Further research involving patients with severe AN found that of the 27 individuals who completed a 20-week CBT-E program, 26 exhibited significant improvements in weight, ED features, and general psychopathology after completion, and these improvements were sustained at 6- and 12-month follow-ups (Dalle Grave, Calugi, El Ghoch, Conti, & Fairburn, 2014). Presently, the evidence indicates that the efficacy of CBT-E is at least as promising as that of other recommended treatment modalities. While RCTs directly comparing CBT-E with “treatment as usual” and other treatment forms are required, these findings suggest that CBT-E holds substantial promise as a treatment option for individuals with AN.
The most recent clinical guidelines from NICE (2017) recommend several treatments for EDs: ED-focused CBT (CBT-ED), Maudsley Anorexia Nervosa Treatment for Adults (MANTRA), specialist supportive clinical management (SSCM), or ED-focused focal psychodynamic therapy (FPT) for AN; BED-focused guided self-help or group or individual CBT-ED for BED; and BM-focused guided self-help or individual CBT-ED for BM. CBT-ED is supported by robust evidence for treating BED or BM, particularly for those who do not initially respond to guided self-help (NICE, 2017). Consequently, CBT-ED is the treatment of choice for most EDs, except for AN, for which several similarly effective options exist. Currently, there are no published guidelines for ARFID.
Conclusion
In conclusion, the existing evidence strongly supports the efficacy of CBT-E as an effective treatment for individuals with EDs other than AN. Research on AN has produced more mixed results, mainly due to the resistance to treatment often associated with this condition, stemming from a lack of motivation, which leads to nonadherence and dropout (Murphy et al., 2010). While moderate evidence suggests that CBT-E is equally as effective as MANTRA, SSCM, or FPT for AN, robust evidence for the effectiveness of any of these treatments is still lacking. Further head-to-head trials are essential to establish the comparative efficacy of CBT-E in the context of other treatments for AN, given the considerable challenges associated with its treatment. Notably, no RCTs have been conducted for ARFID across any treatment modality. Thus, additional research is urgently needed to advance our understanding and treatment options for this condition.