The Feasibility and Ecacy of Emotion-Focused Therapy for Binge-Eating Disorder: A Pilot Randomised Waitlist Control Trial

Background: Research into psychotherapy for binge-eating disorder (BED) has focused mainly on cognitive behavioural therapies, but ecacy, failure to abstain, and dropout rates continue to be problematic. The experience of negative emotions is among the most accurate predictors for the occurrence of binge eating episodes in BED, suggesting benets to exploring psychological treatments with a more specic focus on the role of emotion. The present study aimed to explore the feasibility and ecacy of individual emotion-focused therapy (EFT) as a treatment for BED by examining the outcomes of a pilot randomised waitlist-controlled trial. Methods: Twenty-one participants were assessed using measures of feasibility (recruitment, credibility and expectancy, and therapy retention), and ecacy (objective binge episodes and days, and binge eating psychopathology). The treatment consisted of 12 weekly one-hour sessions of EFT for maladaptive emotions over three months. A mixed model approach was utilised with one between effect (group) using a one-way analysis of variance (ANOVA) to test the hypothesis that participants immediately receiving the EFT treatment would demonstrate a greater degree of improvement on outcomes relating to objective binge episodes and days, and binge eating psychopathology, compared to participants on the EFT waitlist; and one within effect (time) using a repeated-measures ANOVA to test the hypothesis that participation in the EFT intervention would result in signicant improvements in outcome measures from pre to post-therapy and then maintained at follow-up. Results: Recruitment, credibility and expectancy, and therapy retention outcomes indicated EFT is a feasible treatment for BED. Participants receiving EFT demonstrated a greater degree of improvement in objective binge episodes and days, and binge eating psychopathology compared to EFT waitlist control group participants. When participants in the EFT waitlist control group then received treatment and outcomes data were combined with participants who initially received the treatment, EFT demonstrated signicant improvement in objective binge episodes and days, and binge eating psychopathology for the entire sample. Conclusions: These ndings provide further preliminary evidence for the feasibility and ecacy of individual EFT for BED and support more extensive randomised control trials. cognitive behavioral therapies, but ecacy, failure to abstain, and dropout rates continue to be problematic. The experience of negative emotions is among the most accurate predictors for the occurrence of binge eating episodes in BED, suggesting benets to exploring other psychological treatments with a more specic focus on the role of emotion. This pilot study aimed to investigate if emotion-focused therapy (EFT) for BED improved binge episodes, the number of days on which binge episodes occurred, binge eating symptoms, anxiety, and depression. The treatment consisted of 12 weekly one-hour sessions of EFT over three months with 21 participants. Those receiving the EFT demonstrated a greater degree of improvement in binge episodes, the number of days on which binge episodes occurred, and binge eating symptoms compared to participants who did not receive the treatment. The EFT intervention resulted in signicant improvements in binge episodes, the number of days on which binge episodes occurred, binge eating symptoms and anxiety but not depression. In conclusion, these ndings provide further preliminary evidence that individual EFT may be an ecacious treatment for BED. Further controlled studies are needed. IPT, DBT,behavior therapy, non ‐ specic supportive therapy, mindfulness, psychodynamic therapy, and a combined psychotherapy approach. The total weighted percentage of treatment ‐ completers who achieved abstinence at posttreatment was 50.9% and 50.30% at follow-up. The highest abstinence rate was observed in IPT, and clinician ‐ led group treatments produced signicantly higher posttreatment (but not follow ‐ up) abstinence estimates than guided self ‐ help treatments. The meta-analysis demonstrated that 50% of patients with BED do not fully respond to treatment, and there is, therefore, a need to explore other psychotherapies to improve these outcomes. our previous study has been the only study to examine the ecacy of individual EFT for BED (citation blinded for review). This study involved the use of a multiple baseline case series design in which individual EFT over 12 weeks, was applied to six female adult participants with BED, with follow-ups at 2, 4- and 8-weeks posttreatment. All cases experienced reliable recovery from binge-eating psychopathology and also a signicant decrease in binge-eating frequency. There was reliable improvement or recovery for eating and shape concerns for all cases, and improvement on weight concern for the majority of cases; and all cases experienced reliable recovery or improvement in overall emotion regulation. Most cases that were in the clinical range for anxiety at pre-treatmentrecovered,and all cases experienced reliable improvement in, or recovery from, depression. Three of the six cases experienced reliable recovery or improvement in alexithymia. There were no treatment dropouts. This study is a pilot randomized control trial (RCT) designed to support the development of a future denitive RCT and it builds upon ndings from an initial multiple baseline case series design of EFT for BED (citation blinded for review). Participants were initially randomly allocated to either an EFT treatment intervention or waitlist (12-week clinical monitoring preceding treatment)using a block randomization method(33). This is a commonly used technique in clinical trial design which reduced bias and achieves sample size balance when allocating participants to treatment groups. It is particularly useful for smaller sample sizes and increases the probability that each allocation arm will contain an equal number of individuals by sequencing participant assignments by block.This project was approved by the Queensland University of Technology (QUT) University Human Research Ethics Committee (UHREC) and met the requirements of the National Statement on Ethical Conduct in Human Research (2007). The UHREC Reference number is 1700000986 and all participants provided written informed consent. Consolidated Standards of Reporting Trials (CONSORT) guidelines were fully adhered to – See Figure 1.

Binge-eating disorder (BED) is the most prevalent of all the eating disorders (1). There is an estimated prevalence rate of 2.5% to 4.5% in females and 1.0% to 3.0% in males based on international data (2) and a 3month prevalence rate of 5.58% based on Australian data (3). The core symptoms include recurrent episodes of binge eating while experiencing a sense of lack of control in the absence of compensatory strategies (4).
Spielmans et al. (10) noted that for BED, both The National Institute of Clinical Excellence (NICE) in the United Kingdom and the American Psychiatric Association guidelines suggest that cognitive behavior therapy (CBT) is the psychological treatment of choice, with interpersonal therapy (IPT) and dialectical behavior therapy (DBT) serving as second-line interventions (11,12 ). A subsequent meta-analysis examined direct comparisons between psychological treatments for bulimia nervosa (BN) and BED and the role of moderating variables (e.g., the degree to which psychotherapy was bona de or not bona de) based upon criteria published in Wampold,et al. (13). The meta-analysis included 77 comparisons reported in 53 studies and results indicated that: bona de therapies outperformed non-bona de treatments; bona de CBT outperformed bona de non-CBT interventions by a statistically signi cant margin (only approaching statistical signi cance for BN and BED when examined individually), full CBT treatments offered no bene t over their components, and the distribution of effect size differences between bona de CBT treatments was homogeneously distributed around zero. There was little evidence supporting treatment speci city in psychotherapy for BN and BED.
A more recent meta-analysis estimated the prevalence of patients with BED who achieved binge-eating abstinence following psychological or behavioral treatments (14). The most common treatment delivered was CBT (either in a clinician-led or guided self-help format), and other interventions includebehavioral weight loss, behavioral weight loss combined with CBT, IPT, DBT,behavior therapy, non-speci c supportive therapy, mindfulness, psychodynamic therapy, and a combined psychotherapy approach. The total weighted percentage of treatment-completers who achieved abstinence at posttreatment was 50.9% and 50.30% at follow-up. The highest abstinence rate was observed in IPT, and clinician-led group treatments produced signi cantly higher posttreatment (but not follow-up) abstinence estimates than guided self-help treatments.
The meta-analysis demonstrated that 50% of patients with BED do not fully respond to treatment, and there is, therefore, a need to explore other psychotherapies to improve these outcomes.
Individuals with BED often experience di culties with de cits in emotion regulation (15) which can be de ned as the "… attempt to in uence which emotions we have, when we have them, and how these emotions are experienced or expressed" (16, p. 224). The emotion regulation model of binge eating postulates that binge eating occurs in response to intolerable emotional experiences in the absence of more adaptive coping mechanisms (17).Binge eating represents an effort by an individual to regulate emotion by numbing, avoiding or soothing negative or overwhelming affect (18).It occurs in the absence of effective regulation skills related to experiencing and differentiating as well as attenuating and modulating emotions (19), and individuals with BED experience more intense emotions and more signi cant di culties in emotion regulation than individuals without BED (20).
Given that the experience of negative emotions is amongst the best predictors for the occurrence of binge eating episodes in BED (21), outcomes could be improved by psychological treatments with a more speci c focus on the role of emotion. Emotion-focused therapy (EFT) is a compelling treatment for eating disorders and offers a unique framework for understanding the pathogenesis of emotional di culties (either underregulating or over-regulating affect) in this population (22). The goal of EFT is to assist clients in processing unpleasant emotions by attending to and increasing awareness and expression of emotion; learning to tolerate and regulate experience; re ecting upon and make meaning of emotion by symbolizing emotional experience in words; and transforming maladaptive emotions by activating healthy, adaptive emotions together with their associated needs and action tendencies (23). EFT allows the therapy to move beyond the tautological trap (24) of being "not ready to change" and to move forward in recovery work.
According to the EFT model, emotion organizes experience through emotion schemes, which are constructed from lived emotional experience (25). Central mechanisms of change in EFT include the use of adaptive emotion to transform maladaptive emotion schemes that are understood to generate chronic enduring pain and maintain rigid and maladaptive modes of responding to experience (26), and a successful therapeutic relationship, in which the client feels empathically heard, understood, supported and safe (27). This, in turn, alters dysfunctional behavior patterns and decreases the likelihood of eating disorder behaviors being used as an emotional coping mechanism (28 This study involved the use of a multiple baseline case series design in which individual EFT over 12 weeks, was applied to six female adult participants with BED, with follow-ups at 2, 4-and 8-weeks posttreatment. All cases experienced reliable recovery from binge-eating psychopathology and also a signi cant decrease in binge-eating frequency. There was reliable improvement or recovery for eating and shape concerns for all cases, and improvement on weight concern for the majority of cases; and all cases experienced reliable recovery or improvement in overall emotion regulation. Most cases that were in the clinical range for anxiety at pre-treatmentrecovered,and all cases experienced reliable improvement in, or recovery from, depression. Three of the six cases experienced reliable recovery or improvement in alexithymia. There were no treatment dropouts. Given the preliminary evidence of the usefulness of individual EFT for BED from our previous case series study, a more extensive pilot trial to further test the e cacy and dropout rate of individual EFT for BED is required. The current study presents results from a pilot randomized waitlist-controlled trial of individual EFT for BED. This pilot study provides not only a further test of the e cacy of BED for EFT, but also a test of the acceptability of the intervention and estimation of sample sizes needed for future larger randomized control trials examining EFT for BED (32).It was hypothesized that participation in the EFT intervention would result in signi cant improvements in objective binge episodes and days, and binge eating psychopathology(primary outcomes), and anxiety and depression psychopathology (secondary outcomes) compared with the wait-list control group.It was also hypothesized that EFT would result in a lower dropout rate compared to other psychological interventions for BED.

Design
This study is a pilot randomized control trial (RCT) designed to support the development of a future de nitive RCT and it builds upon ndings from an initial multiple baseline case series design of EFT for BED (citation blinded for review). Participants were initially randomly allocated to either an EFT treatment intervention or waitlist (12-week clinical monitoring preceding treatment)using a block randomization method (33). This is a commonly used technique in clinical trial design which reduced bias and achieves sample size balance when allocating participants to treatment groups. It is particularly useful for smaller sample sizes and increases the probability that each allocation arm will contain an equal number of individuals by sequencing participant assignments by block.This project was approved by the Queensland University of Technology (QUT) University Version -SCID-5-RV (34). At present, there is limited reliability or validity data available for the SCID-5-RV; however, it has demonstrated internal consistency (.80) and test-retest reliability (35). Previous versions of Structured Clinical Interview for DSM-IV Axis I Disorders -SCID-I (36), however, have demonstrated a high level of inter-rater reliability (k = .75) for symptoms and 90% accuracy in diagnosis (37).

Objective binge episodes and days
Changes in objective binge episodes and days (occurrence over the previous 7 days) were assessed using items from the Eating Disorder Examination Questionnaire -EDE-Q-6.0 (38). The EDE-Q-6.0 is a self-report measure of eating disorder psychopathology based on the Eating Disorder Examination Interview (39). It is a widely used measure of eating disorder attitudes and behaviors in both community and clinical populations (40). The EDE-Q-6.0 also provides frequency data on the number of episodes of the eating disorder behavior and the number of days on which the behavior occurred. The items used to measure objective binge episodes (i.e.,a discrete episode of overeating of an objectively large amount of food associated with a feeling of loss of control) in the current study were: "Over the past 7 days how many times have you eaten what other people would regard as an unusually large amount of food (given the circumstances)?" and "On how many of these times did you have a sense of having lost control over your eating (at the time that you were eating)?". The item used to measure the number of days objective binge episodes occurred was "Over the past 7 days, on how many days have such episodes of overeating occurred (i.e., you have eaten an unusually large amount of food and have had a sense of loss of control at the time)?". The EDE-Q-6.0 has received support as a reliable and valid measure of eating-related pathology and speci c disordered eating behaviors (41,42). Test-retest reliability across studies ranges from 0.66 to 0.94 for scores on the four subscales (43). The EDEQ-Q-6.0 has demonstrated acceptable levels of internal consistency (α = .90) for the total score in a clinical sample (44).
There are no standardized clinical cut-offs (38).

Binge eating psychopathology
Changes in binge-eating psychopathology were assessed using the Binge Eating Scale -BES (45

Psychiatric comorbidity
Anxiety and depression were assessed using the Beck Anxiety Inventory -BAI (50) and Beck Depression Inventory-II -BDI-II (51). The BAI is one of the most used clinical self-rating scales for measuring the intensity of anxiety (52). Respondents are presented with a list of 21 common symptoms of anxiety and indicate how much they have been bothered by that symptom during the past month. Items are rated on a scale of 0 = not at all to 3 = severely. The total score is calculated by summing the ratings for the 21 items with amaximum possible score of 63. The BAI has high internal consistency (.93) and good test-retest reliability (.75) (53), in addition to robust convergent and discriminant validity (54). Standardized cut off scores are as follows: 0-21 = low anxiety, 22-35 = moderate anxiety and >36 = potentially concerning levels of anxiety.
The BDI-II is one of the most widely adopted measures of depressive symptoms (55). The BDI-II measures

Therapy retention
Participants who completely discontinued attendance were considered dropouts.

Procedures
Participants were initially telephone-screened for BED based on diagnostic criteria, according to DSM-5 (2013).
Twenty-eight participants were telephone-screened, of which ve did not meet the diagnostic criteria for BED.
Twenty-three participants meeting the diagnostic criteria for BED then completed the SCID-5-RV administered by a research assistant with training in clinical psychology. All met the inclusion criteria, but 1 participant chose not to participate due to being unable to commit fully to weekly treatment sessions, and 1 participant did not respond to contact attempts. Twenty-oneparticipants were randomly allocated to either an EFT intervention or 12-week waitlist using a block randomization methodby a statistician independent to the research team. before the study and was not involved in the initial treatment/waitlist randomization process, data collection before or during the study, or data analysis until after the study. Supervision was provided by Distinguished Professor Emeritus, Leslie Greenberg who was also a co-author of the original treatment manual used as a basis for therapy within the current study. Adherence to EFT protocol was reviewed -and recti ed where necessary -during supervision based on video recordings of study treatment sessions.

Statistical Analyses Plan
Initially, abetween-groupexamination was conducted in relation to any signi cant differences between the 10 participants in the EFT intervention and 10 participants in the waitlist control on demographics at baseline. A series of 2 (Group) x 2 (Time) repeated measures analyses of variance (ANOVA) were then used to test the hypothesis that those receiving the treatment would demonstrate a greater degree of improvement on primary outcomes measures relating to objective binge episodes and days, and binge eating psychopathology compared to participants on the waitlist.. Following the between-group analysis, a within-group examination was then conducted in relation to any signi cant differences between the 20 participants who completed treatment on demographics. A series of within-groups repeated measures analyses of variance (ANOVA) was then conducted to test the hypothesis that participation in the EFT intervention would result in signi cant improvements in the primary and secondary outcome measures from pre to post-therapy and then maintained at each follow-up period

Demographics
Between-group differences No signi cant differences were found between the intervention and waitlist control groups in relation to mean age (years), mean age at rst binge (years), gender, marital status, education, and employment status. See Table 1.   Table 2 outlines the between-group changes. Within-group changes Figure 2 and Table 3 outline within-group changes. Objective binge episode days.
There was a signi cant decrease in objective binge episode days within-group scores measured over sixteen-  Table 3]. Pre to posttherapy, the number of participants with severe binge eating range decreased from 14 to 6, and the number of non-binge eating participants increased from 3 to 11. There were 3 participants with mild to moderate binge eating at pre and posttherapy.  Table 3). At pretherapy, there were 2 participants in the severe range, 5 moderate, 5 mild and 8 minimal. At 3-monthfollow-up, there were 3 in the severe range, 4 moderate, and 13 minimal.
Therapy retention.
One participant (4.76%) dropped out after Week 4 of the EFT treatment for family health reasons. All completing participants attended all sessions.

Discussion
To our knowledge this is the rst pilot randomized controlled trial to test the e cacy of individual EFT for BED. In terms of changes to the secondary outcome measures, individual EFT for BED resulted in signi cant improvements in anxiety but not depression psychopathology. These ndings, however, need to be interpreted with caution given that 14 participants were in the mild or minimal range for anxiety psychopathology and 13 participants were in the mild or minimal range for depression psychopathology at pretherapy. This indicates that most participants were not experiencing severe or moderate anxiety or depression symptoms before completion of the EFT intervention. It is also noted that anxiety and depression psychopathology were only measured at pretherapy and follow-up but not during weekly treatment sessions which resulted in a brief snapshot of participant progress rather than a more accurate picture of changes over time.
Page 17/23 The following future sample size calculations were made using GPower 3.1.9.2 with alpha =.05, power = 0.95, 2 groups and 4-time points. Using our between-group effect size for objective binge eating frequency (d=.98) future studies comparing EFT to a waitlist control group will need a minimum sample size of 12. However, if comparing individual EFT with an active psychotherapy (d=0.82; (58)) then future studies would require a minimum sample size of 320 participants to nd an effect. Using our between-group effect size for days without bingeing and loss of control (d=1.39) then future studies comparing EFT to a waitlist control group will need a minimum sample size of 8 participants. If comparing EFT with an active psychotherapy (d=1.04 (58)), then future studies will need a minimum of 70 participants to nd an effect.
The main limitation of the current research is the relatively small sample size which may limit the extent to which the sample is representative of people with binge eating disorder. Additionally, the majority of the sample was female and outcome measures were con ned to self-report measures which limited a participant's descriptions of attitudes and behaviors to those within their awareness. Furthermore, the secondary outcomes measures associated with anxiety and depression psychopathology were administered at pretherapy and follow-up only. Post-treatment follow-up at 16, 20 and 24 weeks was also relatively short, which limited the analysis of participant trajectory and capacity to maintain gains. Finally,therapist effects cannot be ruled out given that the same therapist delivered the treatment, however, a recent investigation indicated that therapist effects account for only 5.8% of the variance in patient outcomes (e.g., 67).
The present study has several implications. Firstly, it provides further preliminary evidence that EFT may be an e cacious treatment for BED and builds upon previous ndings (e.g., 31,68). It also identi ed changes in objective binge episodes and days, binge eating psychopathology,and anxiety psychopathology that are theoretically important to EFT including emotion and emotion regulation. The dropout rate was also relatively low compared to other psychological therapy interventions for BED which indicates acceptability of the EFT intervention.

Conclusions
In conclusion, the evidence is emerging for the bene ts of EFT for BED which has a focus on assisting clients to experience and process unpleasant emotions and decreasing the reliance on an eating disorder as an emotional coping mechanism. Future research assessing EFT for BED needs to include a more extensive randomized control trial with a larger sample size to establish causal conclusions and equal gender representation to improve the generalizability of ndings. Consideration could also be given to a more extended follow-up period to improve the analysis of participant trajectory and capacity to maintain gains and the use of more than one therapist to rule out therapist effects.