Interoceptive Mechanisms of Body Image Disturbance in Anorexia Nervosa

Not Applicable

Recruiting

• Conditions: Anorexia Nervosa; Body Image Disturbance; Interoception
• Interventions: Behavioral: EFT; Behavioral: Floatation-REST; Behavioral: IFT

• Registration Number: NCT06332963
• Lead Sponsor: Laureate Institute for Brain Research, Inc.

Brief 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).

Study Timeline

• Study First Submitted: 2024-03-20
• Study First Submitted QC: 2024-03-20
• Study First Posted: 2024-03-27
• Study Start: 2024-04-19
• Status Verified: 2024-10
• Last Update Submitted: 2024-10-30
• Last Update Posted: 2024-11-01
• Primary Completion: 2028-06
• Study Completion: 2028-12

Recruitment & Eligibility

• Status: RECRUITING
• Sex: Female
• Target Recruitment: 102

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
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 15 to 40 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 (defined as a drop of ≥ 20 mmHg in systolic blood pressure (SBP) or a drop of ≥ 10 mm Hg in diastolic blood pressure (DBP) when measured shortly after transitioning from lying down to standing)
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 > 160 mmHg
9. Diastolic blood pressure >100 mmHg
10. Resting heart rate <50 beats per minute.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Interoceptively Focused Treatment (IFT)	IFT	The IFT intervention will guide participants through a tailored application of present-moment focus toward experiencing awareness and acceptance of bodily signals and defusing thoughts related to those signals. For example, participants will engage in several exercises to increase awareness of body sensations, thoughts, and emotions. IFT consists of one introduction session with a clinician (\~60 minutes) the introduction session was designed as a brief introduction to acceptance- and mindfulness-based concepts with guided practice exercises and closing time for participants to briefly process challenges to execution of exercises and the experience during the session. This is followed by three IFT sessions which combine acceptance- and mindfulness-based skills practice with floatation-REST (Reduced Environmental Stimulation Therapy via floatation).
Exteroceptively Focused Treatment (EFT)	EFT	In the EFT condition, exercises are tailored toward experience of the present moment via external environment mindfulness (i.e., attending to experience) and defusion of thoughts. EFT consists of one introduction session with a clinician (\~60 minutes) the introduction session, similar in format to IFT, introduces acceptance- and mindfulness-based concepts. This is followed by three EFT sessions during which participants engage in brief guided skills training followed by video guided skills practice. The EFT condition is designed to increase awareness of the present moment and experience of the environment and view thoughts or emotions that may impact engagement with the current moment in a nonjudgmental way.
Interoceptively Focused Treatment (IFT)	Floatation-REST	The IFT intervention will guide participants through a tailored application of present-moment focus toward experiencing awareness and acceptance of bodily signals and defusing thoughts related to those signals. For example, participants will engage in several exercises to increase awareness of body sensations, thoughts, and emotions. IFT consists of one introduction session with a clinician (\~60 minutes) the introduction session was designed as a brief introduction to acceptance- and mindfulness-based concepts with guided practice exercises and closing time for participants to briefly process challenges to execution of exercises and the experience during the session. This is followed by three IFT sessions which combine acceptance- and mindfulness-based skills practice with floatation-REST (Reduced Environmental Stimulation Therapy via floatation).

Primary Outcome Measures

Name	Time	Method
Perceptual body image dissatisfaction on the Photographic Figure Rating Scale (PFRS)	Through completion of post-intervention follow-up, within 2 weeks of final intervention	Average change in BID from pre- to post-intervention (range 0 - 9, larger changes indicate greater severity of BID).

Secondary Outcome Measures

Name	Time	Method
Noticing on the Multidimensional Assessment of Interoceptive Awareness version 2 (MAIA-2)	Through completion of post-intervention follow-up, within 2 weeks of final intervention	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)
Attention regulation on the Multidimensional Assessment of Interoceptive Awareness version 2 (MAIA-2)	Through completion of post-intervention follow-up, within 2 weeks of final intervention	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)
Interoceptive attention on the Interoceptive Attention Scale (IATS)	Through completion of post-intervention follow-up, within 2 weeks of final intervention	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)
Body image dissatisfaction on the Somatomap3D	Through completion of post-intervention follow-up, within 2 weeks of final intervention	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)
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)	Through completion of post-intervention follow-up, within 2 weeks of final intervention	Average of the change in appearance evaluation rating from pre- to post-intervention sessions
Overweight preoccupation on the Multidimensional Body-Self Relations Questionnaire- Appearance Scales (MBSRQ-AS) Overweight preoccupation scale	Through completion of post-intervention follow-up, within 2 weeks of final intervention	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)
Cognitive/affective body image on the Body Image State Scale (BISS)	Through completion of experimental sessions, 2-4 weeks after pre-treatment baseline completion	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)
Not worrying on the Multidimensional Assessment of Interoceptive Awareness version 2 (MAIA-2)	Through completion of post-intervention follow-up, within 2 weeks of final intervention	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)
Interoceptive intensity during experimental conditions	Through completion of experimental sessions, 2-4 weeks after pre-treatment baseline completion	Intensity of cardiac, respiratory, and gastric signals measured via visual analog scale pre-to -post experimental conditions, higher values indicate greater intensity
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)	Through completion of post-intervention follow-up, within 2 weeks of final intervention	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).
Body image satisfaction on the Multidimensional Body-Self Relations Questionnaire- Appearance Scales (MBSRQ-AS) Body Areas Satisfaction	Through completion of post-intervention follow-up, within 2 weeks of final intervention	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)
Cardiac interoceptive accuracy on the Heartbeat Tapping Task	Through completion of post-intervention follow-up, within 2 weeks of final intervention	Beat-to-tap consistency measure of the Heartbeat Tapping Task, higher values indicate greater consistency between actual heartbeats and perceived heartbeats.
Cardiac interoceptive intensity on the Heartbeat Tapping Task	Through completion of post-intervention follow-up, within 2 weeks of final intervention	Intensity of cardiac signals measured via visual analog scale during the Heartbeat Tapping Task, higher values indicate greater intensity of perceived heartbeats.
Perceived respiratory interoceptive intensity on the Breath Hold Task	Through completion of post-intervention follow-up, within 2 weeks of final intervention	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
Trust on the Multidimensional Assessment of Interoceptive Awareness version 2 (MAIA-2)	Through completion of post-intervention follow-up, within 2 weeks of final intervention	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)
Not distracting on the Multidimensional Assessment of Interoceptive Awareness version 2 (MAIA-2)	Through completion of post-intervention follow-up, within 2 weeks of final intervention	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)
Emotional awareness on the Multidimensional Assessment of Interoceptive Awareness version 2 (MAIA-2)	Through completion of post-intervention follow-up, within 2 weeks of final intervention	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)
Self-regulation on the Multidimensional Assessment of Interoceptive Awareness version 2 (MAIA-2)	Through completion of post-intervention follow-up, within 2 weeks of final intervention	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)
Body image distortion on the Aperture Task	Through completion of post-intervention follow-up, within 2 weeks of final intervention	Absolute difference between perceived size gap to fit through the aperture and actual shoulder width to pass through
Body image distortion on the String task	Through completion of post-intervention follow-up, within 2 weeks of final intervention	Sum of the absolute difference between perceived body part size measured via string task and actual body size

Trial Locations

Locations (1)

Laureate Institute for Brain Research; 🇺🇸 Tulsa, Oklahoma, United States