A Pilot Test of Mood and Circadian Rhythm Mechanisms Driving Binge Eating

Women (N = 30) who are at least 18 years of age with minimally normal body weight (BMI ≥ 18.5 kg/m2) and exhibit clinically significant binge eating (BE; ≥ 2 BE episodes/week over the previous 3 months) and clinically significant impairment will be eligible to participate. Binge eating will be defined as described in the DSM-5: consuming an objectively large amount of food in a discrete period of time while experiencing a sense of loss of control over eating. The minimum frequency of 2 BE episodes/week will prevent a statistical floor effect from making decreases in BE frequency too small to reliably detect. Further, this frequency should ensure that a sufficient number of BE events occur during the sampling period. A nontreatment-seeking sample is appropriate because the vast majority of individuals with eating disorders do not seek treatment (e.g., 6% of individuals with bulimia nervosa receive mental health services per year).

Participants will be recruited from the community using advertisements (e.g., flyers, newspaper ads, listservs, social media). Advertisements will inform interested individuals that they can complete a brief online or phone-based eligibility screen. Individuals who appear eligible on the online screen will be called by a trained research assistant to confirm the screening results. Thus, all prospective participants will be screened by a trained research assistant over the phone. The eligibility screen is modeled off an existing validated tool (i.e., the Eating Disorder Diagnostic Scale) that is modified to assess specific inclusion/exclusion criteria.

Individuals will be excluded for several factors that impact hormone function, weight, or appetite or may result in changes in binge eating, including medical conditions and/or medication use in the past 6 weeks months and underweight status, or receiving psychotherapy or psychotropic medication for the 6 weeks prior to study entry. In addition, individuals for whom engaging in the manipulation may be dangerous (e.g., those with diabetes or bipolar disorder) will be excluded. Individuals who appear to meet study eligibility based on the telephone screening and are interested in participating will be scheduled for their baseline appointment.

Baseline Assessment The baseline appointment will begin by obtaining informed consent. Participants will be informed of their rights as research participants, the foreseeable risks involved in participation, expected benefits, and other relevant issues (e.g., remuneration schedule).Body Mass Index (BMI) will be assessed via height and weight measured with a stadiometer and digital scale. Inclusion/exclusion criteria will be confirmed via clinical interviews: Eating Disorders Examination (EDE) and Structured Clinical Interview for DSM-5 Axis I disorders (SCID-I). The EDE will be used to confirm current eating disorder symptoms and diagnoses. The SCID-I will be used to assess lifetime history of an eating disorder, and current and lifetime presence of other Axis I disorders that frequently co-occur with eating disorders. The SCID interview will also be used to assess exclusion criteria (e.g., bipolar disorder). Interviews will conducted by doctoral students in clinical psychology who are equivalent to master's degree level mental health professionals. They will be trained by the PI. Their interviews will be audio recorded to assess interrater reliability. Participants will also complete baseline self-report measures at this visit. These include the Clinical Impairment Assessment, the Change in Eating Disorder Symptoms scale, the Pittsburgh Sleep Quality Index, the Center for Epidemiological Studies Depression scale - Revised, the Positive and Negative Affect Schedule, and Subjective Appetite Scales. Prior to leaving this baseline appointment, research assistants will train participants on the use of the therapy light box, the Actiwatch device, and on the proper collection of saliva samples, and they will explain what appointment reminders participants should expect, in addition to querying their preferred method of reminder delivery (e.g., phone call, text, or email).

Ecological Momentary Assessment (EMA) At the first day of the 22-day sampling period, EMA data collection will begin to capture daily eating patterns and subjective loss of control during eating and negative mood. Signal-contingent ratings will be semi-randomly sampled six times per day during waking hours. These will assess the strength of negative mood. These ratings will be made when the Actiwatch device alerts participants by vibrating that a rating is being requested. These assessments take only a moment to complete using an ordered rating scale. Participants will also be asked to complete ratings following eating episodes (Event-contingent ratings). They will indicate the extent of loss of control experienced and the strength of negative mood. These data will allow the investigators to evaluate daily patterns in the timing of eating and rates of dysregulated eating episodes. All ratings provided (i.e., regardless of the type of EMA sampling schedule) are time stamped, so that reports cannot be retrospectively completed or backdated. Data are saved locally to the device and are downloaded when participants return the device to the lab.