Interoceptive Mechanisms of Body Image Disturbance in Anorexia Nervosa

Laureate Institute for Brain Research, Inc.102 enrolled

Overview

The proposed study utilizes a randomized experimental therapeutics design to test a mechanistic framework linking interoceptive processing and disturbed body image, with the purpose of informing the development of future therapies for body image dissatisfaction in anorexia nervosa (AN). A sample of 102 participants will be recruited from the Laureate Eating Disorder Program (LEDP). After being randomized, participants will all receive a one-hour session of acceptance- and mindfulness-based training with a therapist (the introduction session). They will then receive either the interoceptively focused treatment (IFT) or exteroceptively focused treatment (EFT) condition based on randomization. In the IFT condition participants will engage in floatation-REST (Reduced Environmental Stimulation Therapy) while practicing acceptance and mindfulness-based principles. The EFT condition is an exteroceptive intervention in which participants will be asked to view pre-recorded videos of acceptance and mindfulness-based skills to aid in the practice of these skills. Each condition will consist of one introduction session and three experimental sessions. All participants will then return for follow-up measures. Assessed outcomes will include acute changes in body image disturbance (BID) and interoception. Further, longitudinal intervention effects on self-reported eating disorder symptoms, body image dissatisfaction, and interoception; behavioral measures of interoception and body image dissatisfaction; and resting state and interoceptive functioning during functional magnetic resonance imaging (fMRI) will be explored.

Anorexia nervosa (AN) accounts for more than 10,000 deaths per year in the United States alone, marking it as a psychiatric disorder with one of the highest standardized mortality rates. Current AN treatments have only moderate efficacy and result in relapse rates as high as 50% within one year of hospitalization. A poor understanding of the pathophysiology of AN, particularly the core diagnostic feature of body image disturbance (BID), has hindered treatment development. Abnormal interoceptive processing (i.e., internal body signal) has been proposed to contribute to BID and a mechanistic delineation of the association between interoception and BID could lead to novel interventions for AN. This proposal uses a behavioral experimental therapeutics approach to determine how modulating interoceptive processing affects BID in AN. Body image, defined as the multifaceted experience of one's physical appearance, is comprised of cognitive, affective, and perceptual components. BID is a key diagnostic feature of AN that is associated with poor outcomes, including relapse following hospital discharge. It is slow to improve in women with AN, and has been consistently identified as a factor contributing to the persistence of AN symptoms and relapse following treatment. Perceptual BID is a complex and poorly understood facet proposed to involve the integration of body-related visual signals with representations of interoceptive signals. Studies indicate women with AN overestimate their body size. Standard of care treatments for AN, such as Cognitive Behavioral Therapy, focus on modifying the cognitive/affective components of BID but rarely address the perceptual component, making it an under-investigated therapeutic target. Diminished sensitivity to interoceptive body signals in AN may lead to an overreliance on exteroceptive (i.e., visual) body-related signals, which in turn, is likely to facilitate self-objectification (seeing one's body as an object). The outcome of this process is an inaccurate representation of physical body characteristics (i.e., perceiving one's body as larger than its true size) despite continuing to focus on it excessively. To explore whether the modulation of interoceptive signaling could improve perceptual BID in AN, we recently utilized a non-pharmacologic intervention called floatation-REST (Reduced Environmental Stimulation Therapy). During floatation-REST, input from visual, auditory, olfactory, gustatory, thermal, tactile, vestibular and proprioceptive channels are minimized, and interoceptive input is enhanced. Across two clinical trials in AN we have found that floatation-REST acutely reduces perceptual BID, indexed by the body dissatisfaction score on the Photographic Figure Rating Scale (PFRS), after one session and reliably after multiple sessions. Acceptance and commitment therapy (ACT) for eating disorders and body image has been examined previously and evidence supports the reduction of cognitive/affective BID symptoms. The proposed study will combine floatation-REST with interoceptively focused acceptance- and mindfulness-based components (interoceptively focused therapy \[IFT\]). The primary purpose of the proposed study is to examine the acute synergistic effects of IFT and float on BID. Further, the proposed study will be the first to systematically examine associations between BID and interoception using multiple levels of analysis (i.e., self-report and behavioral assays and neuroimaging) and combine them with perturbations of interoceptive and cognitive processing to examine the impact of interoception on perceptual BID. All participants will receive a one-hour introduction session prior to being randomized on a 1:1 basis to receive three 45-minute floatation-REST sessions (to attenuate exteroceptive input and enhance interoceptive input) paired with IFT or three 45-minute self-guided exteroceptive practice sessions (active comparator to enhance cognitive/affective BID, EFT group). During the IFT/EFT sessions the skills presented have been matched as closely as possible with the exception of the focus. For example, both groups engage in contact with the present moment exercises. In the IFT group, the focus is internal body sensations; whereas in the EFT group, the focus in the experience outside the individual (e.g., their environment sights, sounds, etc). While ACT is typically conducted in longer intervals (10+ weeks of 1 hour sessions), there is growing evidence to support the potential of briefer ACT interventions. Both groups will complete behavioral and self-report assays of interoception, perceptual and cognitive/affective BID, and state/trait illness measures pre- and post-experimental session; pre and post intervention measures including self-report, behavioral, and neurobiological assays (specifically functional magnetic resonance imaging); and longitudinal follow-ups. The ability to reliably improve BID marks a step forward in the search for more effective BID treatments for AN. Given that it is expected that acceptance and mindfulness-based components will impact affective components of body image, it is expected that there will be an additive effect on the primary outcome (perceptual BID).

Interventions

Floatation-RESTBEHAVIORAL

Participants lay supine in one of two circular fiberglass pools that were custom-designed for research purposes. The floatation pools are 8 feet in diameter and contain 11 inches of reverse osmosis water saturated with \~1,800 pounds of Epsom salt (magnesium sulfate). This creates a dense saltwater solution with a specific gravity of \~1.26, allowing participants to effortlessly float on their back while the water hovers just above the ears. The temperature of the water and air is calibrated to approximate skin temperature (\~95.0 °F), helping to minimize the need for thermoregulation while reducing the boundary between air, body, and water. Clothing is usually not worn while floating since anything touching the body can generate somatosensory stimulation, detracting from the float experience. However, participants have the option to choose if they would prefer to float with a bathing suit or nude. During floatation-REST, visual, auditory, olfactory stimuli are minimized.

IFTBEHAVIORAL

Two ACT principles, contact with the present moment and cognitive defusion were utilized in the development of the intervention. In the IFT condition, awareness and acceptance of bodily signals, thoughts, and emotions and being present with one's self (i.e., mindfulness focus is inward) are emphasized. All participants will engage in an introduction session. Followed by three IFT sessions. The experimental sessions are formatted the same for both conditions. Each begins with a clinician reviewing previous constructs and introducing a new skill. Then participants engage in their assigned condition intervention, followed by a debrief with a clinician. Practices in both conditions are matched as closely as possible for content. The mindful focus of IFT is internal toward thoughts, emotions, and body sensations. In the experimental sessions, participants will engage in a floatation-REST session while practicing acceptance and mindfulness-based skills presented to them.

EFTBEHAVIORAL

Two acceptance and commitment therapy modules contact with the present moment and cognitive defusion were utilized in the development of the intervention. In the EFT condition, awareness and acceptance of thoughts and emotions and mindfulness of current experience are emphasized. The mindful focus of EFT is external, toward attending to experience as well as thoughts and emotions. During experimental sessions, participants will engage in a self-guided and computer-based practice of acceptance and mindfulness-based skills. These videos were created to ensure content was congruent with the material presented in the introduction sessions and represent skills that build from session to session.

Eligibility

Sex: FEMALEMin age: 13 YearsMax age: 50 Years

Medical Language ↔ Plain English

Inclusion Criteria: 1. Primary diagnosis of anorexia nervosa 2. Photographic Figure Rating Scale (PFRS) body dissatisfaction score greater than or equal to 1 3. Eating Disorder Examination Questionnaire (EDE-Q6) Shape Concern Subscale score greater than or equal to 3 4. Weight restored to body mass index (BMI) greater than or equal to 17.5 5. No current evidence of orthostatic hypotension or if there is no evidence of additional fall risk as determined by their provider 6. Clinical status transition from acute to residential status 7. No new psychiatric medications in the week prior to randomization 8. Female sex assigned at birth 9. Ages 13 to 50 years 10. Independently ambulatory 11. Ability to lay flat comfortably 12. English proficiency 13. Willingness and ability to participate in study procedures 14. Provision of informed consent (parent consent and minor assent if less than 18 years of age). Exclusion Criteria: 1. Active suicidal ideation with plan and intent 2. Active cutting or skin lacerating behaviors 3. Pregnancy as defined by urine screening 4. Acute intoxication as indicated by urine drug screen or breathalyzer 5. Orthostatic hypotension as determined by medical provider, evidenced in chart (defined as a drop of ≥ 20 mmHg in systolic blood pressure (BP) or a drop of ≥ 10 mm Hg in diastolic blood pressure (BP) when measured shortly after transitioning from lying down to standing). If evidence of orthostasis is present in chart consultation with provider to determine if status creates additional fall risk. If participant is determined to be at increased fall risk (e.g., dizziness upon standing) they will be excluded. 6. Seizure reported within the previous 12 months 7. Co-morbid diagnoses of Diagnostic and Statistical Manual of Mental Disorders, 5th ed. (DSM-5) bipolar disorder, schizophrenia, or other psychosis spectrum disorder 8. Systolic blood pressure \&amp;gt; 160 mmHg 9. Diastolic blood pressure \&amp;gt;100 mmHg 10. Resting heart rate \&amp;lt;50 beats per minute.

Outcomes

Primary Outcomes

Perceptual body image dissatisfaction on the Photographic Figure Rating Scale (PFRS)

Average change in acute body image dissatisfaction from pre- to post-experimental sessions across all three sessions (range 0 - 9, larger changes indicate greater severity of BID)

Time frame: Through completion of experimental sessions, 2-4 weeks after pre-treatment baseline completion

Perceptual body image dissatisfaction on the Photographic Figure Rating Scale (PFRS)

Average change in BID from pre- to post-intervention (range 0 - 9, larger changes indicate greater severity of BID).

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Secondary Outcomes

Cognitive/affective body image on the Body Image State Scale (BISS)

Average of the change in state cognitive affective body image state pre- to post-experimental sessions across all three sessions. Items 2,4,6 are reverse coded (range 1 to 9, higher scores indicate greater satisfaction with body image)

Time frame: Through completion of experimental sessions, 2-4 weeks after pre-treatment baseline completion

Body image dissatisfaction on the Somatomap3D

Average of the change in anxiety rating from pre- to post-intervention sessions (measured in difference size estimation from Somatomap3D current to ideal in cm, larger discrepancy indicates greater body dissatisfaction)

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Appearance evaluation on the Multidimensional Body-Self Relations Questionnaire- Appearance Scales (MBSRQ-AS) Appearance Evaluation Subscale (range 7 to 35, higher scores indicate more satisfaction with appearance)

Average of the change in appearance evaluation rating from pre- to post-intervention sessions

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Appearance orientation on the Multidimensional Body-Self Relations Questionnaire- Appearance Scales (MBSRQ-AS) Appearance Orientation Subscale (range 7 to 35, higher scores indicate more satisfaction with appearance)

Average of the change in appearance orientation rating from pre- to post-intervention sessions (range 12 to 60, higher scores indicate more importance placed on appearance).

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Body image satisfaction on the Multidimensional Body-Self Relations Questionnaire- Appearance Scales (MBSRQ-AS) Body Areas Satisfaction

Average of the change in body image satisfaction rating from pre- to post-intervention sessions (scores range from 9 to 45, higher scores indicate more content with body appearance)

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Overweight preoccupation on the Multidimensional Body-Self Relations Questionnaire- Appearance Scales (MBSRQ-AS) Overweight preoccupation scale

Average of the change in preoccupations with gaining weight from pre- to post-intervention sessions (scores range from 4 to 20, higher scores indicate higher preoccupation)

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Noticing on the Multidimensional Assessment of Interoceptive Awareness version 2 (MAIA-2)

Average change in awareness of body sensations from pre- to post-intervention sessions (scores range from 0 to 5, higher scores indicate more self-reported awareness of body sensations)

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Not distracting on the Multidimensional Assessment of Interoceptive Awareness version 2 (MAIA-2)

Average change in extent one distracts from unpleasant sensations from pre- to post-intervention sessions (scores range from 0 to 5, higher scores indicate more adaptive response to unpleasant body sensations)

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Not worrying on the Multidimensional Assessment of Interoceptive Awareness version 2 (MAIA-2)

Average change in extent one worries about unpleasant physical sensations from pre- to post-intervention sessions (scores range from 0 to 5, higher scores indicate less rumination about unpleasant body sensations)

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Attention regulation on the Multidimensional Assessment of Interoceptive Awareness version 2 (MAIA-2)

Average change in ability to sustain and control attention to body sensations from pre- to post-intervention sessions (scores range from 0 to 5, higher scores indicate less rumination about unpleasant body sensations)

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Emotional awareness on the Multidimensional Assessment of Interoceptive Awareness version 2 (MAIA-2)

Average change in ability to awareness and connection between body and emotional states from pre- to post-intervention sessions (scores range from 0 to 5, higher scores indicate more awareness of the connection between emotion and body states)

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Self-regulation on the Multidimensional Assessment of Interoceptive Awareness version 2 (MAIA-2)

Average change in ability to regulate distress through attention to body sensations from pre- to post-intervention sessions (scores range from 0 to 5, higher scores indicate more regulation)

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Trust on the Multidimensional Assessment of Interoceptive Awareness version 2 (MAIA-2)

Average change in experiences of one's body as safe and trustworthy ability to regulate distress through attention to body sensations from pre- to post-intervention sessions (scores range from 0 to 5, higher scores indicate more trust in body)

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Interoceptive attention on the Interoceptive Attention Scale (IATS)

Average change in attention to interoceptive signals from pre- to post-intervention sessions (scores range from 21 to 105, higher scores indicate greater self-reported attention to internal signals)

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Cardiac interoceptive accuracy on the Heartbeat Tapping Task

Beat-to-tap consistency measure of the Heartbeat Tapping Task, higher values indicate greater consistency between actual heartbeats and perceived heartbeats.

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Cardiac interoceptive intensity on the Heartbeat Tapping Task

Intensity of cardiac signals measured via visual analog scale during the Heartbeat Tapping Task, higher values indicate greater intensity of perceived heartbeats.

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Interoceptive intensity during experimental conditions

Intensity of cardiac, respiratory, and gastric signals measured via visual analog scale pre-to -post experimental conditions, higher values indicate greater intensity

Time frame: Through completion of experimental sessions, 2-4 weeks after pre-treatment baseline completion

Perceived respiratory interoceptive intensity on the Breath Hold Task

Intensity of panic, suffocation, and anxiety during breath hold task measured via visual analog scale pre-to -post experimental conditions, higher values indicate greater intensity

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Body image distortion on the Aperture Task

Absolute difference between perceived size gap to fit through the aperture and actual shoulder width to pass through

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Body image distortion on the String task

Sum of the absolute difference between perceived body part size measured via string task and actual body size

Time frame: Through completion of post-intervention follow-up, within 2 weeks of final intervention

Interoceptive Mechanisms of Body Image Disturbance in Anorexia Nervosa

Overview

Conditions

Interventions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Secondary Outcomes

Central Contacts