A Pilot Test of Mood and Circadian Rhythm Mechanisms Driving Binge Eating
A Pilot Test of Mood and Circadian Rhythm Mechanisms Driving Binge Eating
Mood and circadian rhythm disruptions are associated with binge eating (BE). BE is a
 discrete, episodic behavior characterized by 1) eating an objectively large amount of food
 and 2) experiencing a subjective sense of loss of control. BE episodes are often preceded by
 negative mood states, and a subtype of individuals with BE has high levels of negative moods.
 This group has more comorbid psychopathology and a poorer response to treatment. Thus,
 understanding the role of negative mood is a critical area for research on BE. Individuals
 with BE demonstrate disruptions in several circadian rhythms, including diurnal meal timing,
 hormone patterns (e.g., daily cortisol rhythms), and mood variations. The most potent
 synchronizer of circadian rhythms is light. Thus, exposure to light may explain other
 phenomena that fluctuate similarly, such as mood and the occurrence of BE. Mood is subject to
 the influence of light, and BE is also influenced by exposure to bright light. It is unknown
 whether regulating circadian rhythms via regular exposure to light improves BE through its
 effects on mood or via changes in other biological or behavioral rhythms. This knowledge can
 inform the development of treatments targeting biobehavioral mechanisms that maintain BE and
 indicate for whom this may be most effective. This project aims to test the roles of negative
 mood and circadian rhythms in the relationship between light exposure and BE and identify
 subtypes of individuals in whom this effect is strong. The investigators hypothesize that
 individuals exposed to less natural bright light will experience more frequent BE, more
 negative mood, and a blunted morning cortisol response. The investigators further hypothesize
 that manipulating exposure to artificial bright light will reduce the frequency of BE and
 negative mood and increase the morning cortisol response. Finally, the investigators
 hypothesize that the effects of this artificial bright light exposure on BE frequency will be
 mediated by changes in negative mood, which itself will be accounted for by changes in
 circadian rhythms as indicated by the morning cortisol response. Additionally, the
 investigators have two moderation hypotheses: that the effects of artificial bright light
 exposure on BE will be greater for those who fit the high negative mood type than those who
 do not and that the effects will be greater for individuals with a blunted morning cortisol
 response at baseline than for those without.
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.

 Randomization The covariate adaptive randomization method will be used to accomplish
 randomization of participants to conditions while assuring that participants are equally
 allocated to each of the two conditions (i.e., normal light first or bright light first).

 Normal Light (control) During the normal light phase, participants will be instructed to sit
 with their faces approximately 22 inches away from the therapy light for 30 minutes each day,
 starting 30 minutes after waking. The lights will be preset to deliver ~500lux at this
 distance. This phase will last 10 days. On the 10th day, participants will return the light
 to the lab (and if this was their first light phase, pick up a new light) and complete
 self-report measures. These measures include the the Change in Eating Disorders Symptoms
 scale, the Center for Epidemiological Studies Depression scale - Revised, and subjective
 appetite scales.

 Bright Light Manipulation (active) During the bright light phase, participants will be
 instructed to sit with their faces approximately 22 inches away from the therapy light for 30
 minutes each day, starting 30 minutes after waking. The lights will be preset to deliver
 ~10,000lux at this distance. This phase will last 10 days. On the 10th day, participants will
 return the light to the lab (and if this was their first light phase, pick up a new light)
 and complete self-report measures. These measures include the the Change in Eating Disorders
 Symptoms scale, the Center for Epidemiological Studies Depression scale - Revised, and
 subjective appetite scales.

 Actiwatch Spectrum PRO® The Actiwatch Spectrum PRO® by Philips Respironics is a wrist-worn
 device that quantifies movement using 3-axis accelerometry. The device uses a cantilevered
 piezoelectric beam to measure the direction and intensity of movement. In combination with
 the accompanying software, validated algorithms compute sleep and wake times, sleep
 efficiency, and nighttime awakenings and provide information on daytime activity. Movement
 data are sampled in 1-minute epochs, which the device can store for up to 30 days of
 continuous monitoring without charging or needing to upload data. This epoch length allows
 for a largely uninterrupted view of movement, and therefore precise timing of the sleep
 period. In addition to the accelerometer, this device contains an ambient light monitor,
 which uses a photodiode element with a spectral frequency responsivity that is similar to the
 human eye (i.e., 330 to 720 nanometers), characterizing the brightness of light falling on
 the device from 0.1 to 150,000 lux (+/-2%). The data collected with the light monitor can be
 a useful adjunct to the sleep algorithm, as changes to ambient light are often driven by
 behavioral constraints on the sleep episode. Critically, for this study, the measurement of
 light will allow for quantifying participants' exposure to naturally occurring light during
 the period of manipulation of light in addition to confirming adherence to the light
 manipulation itself. Finally, this device is waterproof at 1 meter for 30 minutes, meaning
 participants can do all normal daily tasks while wearing the device, except swimming/diving.

 Hormone Assessment Saliva samples for cortisol will be collected on six days: the first and
 second days (prior to any light manipulation), the 11th and 12th days (at the end of the
 first light manipulation) and the 21st and 22nd days (at the end of the second light
 manipulation).

 Salivary Cortisol: Cortisol awakening response levels will be collected at home via passive
 drool saliva samples (0.5 ml) at three times: immediately upon waking, 15 minutes after
 waking, and 30 minutes after waking. Cortisol saliva-serum correlations are high (r = .91),
 and saliva is advantageous over serum because collection is less invasive and levels reflect
 the biologically active fraction of the hormone. Standard collection (e.g., no brushing their
 teeth, eating, chewing gum for 1 hour prior) and storage (i.e., immediately freeze at -20 °C)
 procedures will be followed. Samples will be analyzed using commercially available high
 sensitivity enzyme immunoassays kits from Salimetrics, LLC (Carlsbad, CA, USA). Salimetrics
 cortisol assay characteristics are excellent in terms of minimum detection, intra-assay and
 inter-assay coefficients, spike recovery, and linearity, and samples will be run in
 triplicate to ensure reliable results. Samples will be tested according to the testing
 protocol provided by Salimetrics, LLC.
Inclusion Criteria:

 1. Female sex

 2. Age of at least 18 years

 3. Minimally normal body weight (BMI ≥ 18.5 kg/m2)

 4. Clinically significant binge eating (i.e., ≥ 2 binge-eating episodes/week over the
 previous 3 months

 5. Clinically significant eating disorder-related impairment (indicated by a score of >
 16 on the Clinical Impairment Assessment)

 Exclusion Criteria:

 1. Receiving psychotherapy or psychotropic medication for the 6 weeks prior to study
 entry.

 2. Presence of medical conditions or medications that result in changes in hormone
 function, weight or appetite.

 3. Lifetime presence of bipolar disorder.