NCT06332963

Interoceptive Mechanisms of Body Image Disturbance in Anorexia Nervosa

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 102 (estimated)
• Sponsor: Laureate Institute for Brain Research, Inc. · Academic / Other
• Sex: Female
• Age: 13 Years – 50 Years
• Healthy volunteers: Not accepted

Summary

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.

Detailed description

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).

Conditions

• Anorexia Nervosa
• Body Image Disturbance
• Interoception

Interventions

Type	Name	Description
BEHAVIORAL	Floatation-REST	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.
BEHAVIORAL	IFT	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.
BEHAVIORAL	EFT	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.

Timeline

• Start date: 2024-04-19
• Primary completion: 2028-06-01
• Completion: 2028-12-01
• First posted: 2024-03-27
• Last updated: 2025-09-26

Locations

1 site across 1 country: United States