Dialectical Behavior Therapy Guided Self-Help for Binge Eating Disorder
Condition: Binge Eating Disorder
MeSH terms: Bulimia; Feeding and Eating Disorders; Binge-Eating Disorder
Study type: Interventional

Summary: 
      This study will compare unguided and guided dialectical behavior therapy (DBT) self-help to
      an attention-placebo self-help control condition. Participants with binge eating disorder
      will be randomly assigned to one of the three self-help conditions for 12 weeks. Six guided
      self-help sessions will take place via secure video-calling. Assessments will take place
      before, mid-way through, and after the self-help program as well as at 3-month follow-up. Six
      guided self-help sessions will take place via secure video-calling.
    

Detailed description: 
      STUDY OBJECTIVES AND HYPOTHESES The primary objective of this randomized controlled trial is
      to compare the effectiveness of two methods of administering a dialectical behavior therapy
      (DBT) self-help intervention in a community sample of individuals with BED in NL: guided DBT
      self-help (DBT-GSH) and unguided DBT self-help (DBT-USH). A third condition designed to
      control for non-specific or common factors (e.g., receiving a self-help book) will also be
      included (NS-SH). This condition will be a self-help manual focused on improving low
      self-esteem using CBT strategies with no reference to binge eating.

      METHODS

      Sample size calculation:

      Power analysis was based on the primary outcome variable: frequency of binge eating episodes.
      Assuming the three randomized groups (DBT-USH, DBT-GSH and NS-UGS) are equivalent at
      baseline, a between groups ANOVA will be used to compare them at post-treatment. Based on the
      findings of Masson et al. (2014), assuming an effect size of 0.40 and Type 1 error rate equal
      to .05, a sample size of at least 21 participants per group will yield 80% power. Assuming an
      attrition rate of 20%, we will require 25 participants per group.

      Procedure:

      Recruitment: Participants will be recruited from the community in the province of
      Newfoundland and Labrador (NL), Canada. Family doctor practices around the province will be
      informed about the study and brochures/posters will be sent to them. Posters advertising the
      study will be posted in hospitals, colleges, medical clinics, and universities.
      Advertisements will be placed on a local radio website and the PI will appear on the radio to
      advertise the study. Interested participants will be instructed to go to a website where they
      will fill in an initial screening questionnaire. Those who appear to meet the study inclusion
      criteria will be scheduled for an initial assessment interview via telephone or video-calling
      to confirm their eligibility.

      Study inclusion/exclusion criteria:

      Inclusion criteria: Participants will be male or female aged 18 and older who meet the DSM-5
      diagnostic criteria for BED based on Eating Disorder Examination (Version 17). Additional
      inclusion criteria will include: 1) body mass index (BMI; kg/m2) of at least 18.5; 2) ability
      to read English; 3) high school graduate or equivalent; and 4) access to a computer, tablet
      or cell phone (with camera and microphone) and to high speed internet.

      Exclusion criteria: Participants will be excluded for the following reasons: a) current
      specialized psychological treatment specifically for BED; b) current major medical illness
      that would interfere with treatment (e.g., cancer); c) current acute suicidal risk as
      assessed using the BDI-II ; d) current substance use disorder; and e) current psychotic
      symptoms . Individuals on a stable dose of antidepressant medication and/or sleep medication
      for at least 3 months will be eligible to take part.

      Randomization: Participants will be randomized to one of the three intervention conditions
      (DBT-USH or DBT-GSH or NS-SH) using block randomization, with a block size of 5. Since no
      reliable predictors of BED outcome have been identified to date, we will not stratify the
      groups. The randomization list will be prepared by a research assistant not involved in the
      current study.

      Interventions: Treatment will last 12 weeks in all conditions. Participants in both DBT
      self-help conditions will be provided with the DBT self-help manual "Dialectical Behavior
      Therapy for Binge Eating: A Self-Help Program". This manual is a self-help version of the
      well-established therapist-administered DBT treatment manual used in previous trials of DBT
      for BED. It consists of nine modules that aim to teach three skills to help participants stop
      binge eating: mindfulness, distress tolerance and emotion regulation. In the GSH condition,
      participants will receive six 30-minute one-on-one GSH sessions via a secure web-based
      video-calling program (Bluejeans) with a clinical psychology doctoral student therapist. GSH
      sessions will take place weekly for the first 2 weeks, biweekly for 6 weeks and then a final
      session will take place at week 12. The video-calling program allows GSH sessions to be
      recorded for supervision and treatment monitoring purposes. GSH therapists will have weekly
      group supervision meetings with the principal investigator to discuss any questions or
      challenges that arise. In both unguided self-help conditions, participants will be asked to
      do their best to follow the advice in the self-help manual on their own over the next 12
      weeks.

      Therapist Training and Supervision: After completing preparatory readings, therapists will
      attend a half-day training workshop with the principal investigator (JCM). Thereafter,
      therapists will meet weekly with JCM for group supervision to ensure competence and adherence
      to the GSH therapist manual.

      Guided Self-Help (GSH) Therapist Manual. This manual was used in three previous CBT GSH
      trials, including one by the PI. It was adapted for the present study to guide therapists'
      DBT-GSH sessions.

      Therapist Adherence to the GSH Therapist Manual: A random sample of 15% of video-taped GSH
      sessions will be reviewed by an independent rater to insure adherence to the Therapist
      Manual.

      Participant drop-out: Consistent with an intention-to-treat approach, participants who drop
      out will be asked to continue to participate in the study assessments. To assess participant
      adherence, we will measure the number of times participants access the self-help manual
      website and the number of minutes they spend on each module. The number of eligible
      individuals who: decline to participate, are randomized, begin the study, or drop out of the
      study (and the week at which this occurs) will be recorded.

      Assessment Measures: Except for the initial assessment interview, which will be conducted via
      video-calling, all study measures will be administered on-line via Qualtrics. Measures will
      be administered at baseline (Week 1), and post-treatment (Week12), as well as 3-month
      follow-up. A subset of measures (EDE-Q and DERS) will also be administered at mid-treatment
      (week 6).

      Demographic variables:

      Age, body weight, height, weight history, marital status, education level, ethnicity, age of
      onset of binge eating, and treatment history will be collected at baseline. Body weight will
      also be re-assessed at mid- and post-treatment.

      Eating Disorder Psychopathology:

        -  Eating Disorder Examination Interview, Version 17 (EDE).

        -  Eating Disorder Examination Questionnaire (EDE-Q 6.0). General Psychological Distress

        -  Brief Symptom Inventory (BSI). Emotion Regulation

        -  Difficulties with Emotion Regulation Scale (DERS). Treatment Suitability and Expectancy
           (TSE)

        -  Perceived treatment suitability and expectations will be measured at baseline using two
           10-point visual analogue scales used in previous self-help study on eating disorders.

      Statistical analyses: The primary analysis will focus on the main outcome variable - number
      of binge eating episodes over the previous 28 days. If, after randomization, the three groups
      (i.e., GSH and USH) are equivalent at baseline, then an ANOVA will be used to compare the
      groups on binge eating frequency at post-treatment. Impact on eating disorder
      psychopathology, general psychological distress, quality of life, and difficulties with
      emotion regulation will also be examined. Eating disorder psychopathology, general
      psychological distress, quality of life, and difficulties with emotion regulation will also
      be examined.
    

Intervention name(s): DBT Guided Self-Help; DBT Unguided Self-Help; Self-Esteem-Focused Unguided Self-Help
Intervention type(s): Behavioral; Behavioral; Behavioral
Intervention description(s): DBT self-help manual plus six 30-minute therapy sessions for 12 weeks; DBT self-help manual without any therapy sessions for 12 weeks; Self-esteem focused self-help manual without any therapy sessions for 12 weeks
Allocation: Randomized
Intervention model: Factorial Assignment
Masking: None (Open Label)
Primary purpose: Treatment