By Alexis Dumain

Anorexia nervosa (AN) is a serious disorder that is difficult to treat, and relapse is common.^1-4 One reason it may be difficult to treat may be that established interventions are not targeting the root of the disorder.^5,6 Enhanced Cognitive Behavioral Therapy, or CBT-E, the standard treatment for eating disorders, focuses on unhelpful thought patterns (e.g., “I am fat”) and replacing harmful behaviors, like restriction.⁷ However, recent research suggests that bodily processes, in addition to unhelpful thought patterns, may be at the core of AN and other eating disorders.^8-13

Interoception describes the processes by which we detect, interpret, and respond to our body’s automatic signals, such as hunger, fullness, temperature, and thirst.^13,14 Although this field of research is in its early stages, studies have found that people with AN may have trouble sensing, interpreting, and responding to these interoceptive signals.¹⁴ Additionally, this difficulty is persistent, meaning it is often present even after recovery, and some evidence suggests it develops early in childhood.^9,15

The study results are conflicting as to whether people with AN are more, or less, sensitive to interoceptive signals, such as hunger. Some studies have found that people with AN are more sensitive, meaning they perceive small changes in internal sensations more intensely than the average person,^9,16-18 and that they experience these changes in sensation negatively.^9,11 These interoceptive differences are reflected in different and heightened activity in brain areas associated with interoception—such as the insula—as well as disturbances in body image.^9,19

Other studies have found that people with AN are less sensitive, or have more trouble sensing changes in interoceptive signals, such as hunger and fullness.^8,20,21 Interestingly, regardless of whether individuals with AN are more or less sensitive, researchers propose that they may use food restriction as a way to “quiet” these distressing internal cues or to create a single dominant and predictable signal that they know how to interpret.²²

Interoception is uniquely linked to mental health, given its association with survival.²⁴ We need to be able to know when we are hungry and thirsty, and what to do about it, in order to live. Therefore, problems with interoception are theoretically quite distressing and can adversely affect health. They may also increase risk that one turns to unhealthy ways of regulating internal stimuli, such as restricting. Treatments are beginning to emerge that incorporate aspects of interoception into the intervention. One such treatment is interoceptive exposure, a technique that is already used to treat panic disorder.^25,26 In interoceptive exposure, a person is helped to build up their tolerance for triggering internal sensations, such as a full stomach in the case of an eating disorder. Once they learn how to properly interpret this sensation and prevent “safety behaviors,” such as restricting or purging, they are better equipped to interpret and respond to similar sensations in the future. When combined with therapies that treat unhelpful thoughts and behaviors, research about interoception and AN may help clinicians treat eating disorders by helping individuals to better understand, interpret, and respond to their bodies’ cues. 

References

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² Eddy, K. T., Tabri, N., Thomas, J. J., Murray, H. B., Keshaviah, A., Hastings, E., Edkins, K., Krishna, M., Herzog, D. B., Keel, P. K., & Franko, D. L. (2017). Recovery from anorexia nervosa and bulimia nervosa at 22-year follow-up. The Journal of Clinical Psychiatry, 78(02), 184–189. https://doi.org/10.4088/JCP.15m10393

³ Arcelus, J., Mitchell, A. J., Wales, J., & Nielsen, S. (2011). Mortality rates in patients with anorexia nervosa and other eating disorders. A meta-analysis of 36 studies. Archives of General Psychiatry, 68(7), 724.

⁴Chesney, E., Goodwin, G. M., & Fazel, S. (2014). Risks of all-cause and suicide mortality in mental disorders: A meta-review. World Psychiatry, 13(2), 153–160. https://doi.org/10.1002/wps.20128

⁵ Morris, J., & Twaddle, S. (2007). Anorexia nervosa. BMJ, 334(7599), 894–898. https://doi.org/10.1136/bmj.39171.616840.BE

⁶  Linardon, J., de la Piedad Garcia, X., & Brennan, L. (2016). Predictors, moderators, and mediators of treatment outcome following manualised cognitive-behavioral therapy for eating disorders: A systematic review: predictors, moderators, and mediators of outcome for eating disorders. European Eating Disorders Review, 25(1), 3–12. https://doi.org/10.1002/erv.2492

⁷ Dalle Grave, R., Calugi, S., El Ghoch, M., Conti, M., & Fairburn, C. G. (2014). Inpatient cognitive behavior therapy for adolescents with anorexia nervosa: Immediate and longer-term effects. Frontiers in Psychiatry, 5, 14. https://doi.org/10.3389/fpsyt.2014.00014

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¹⁰ Kerr, K. L., Moseman, S. E., Avery, J. A., Bodurka, J., Zucker, N. L., & Simmons, W. K. (2016). Altered insula activity during visceral interoception in weight-restored patients with anorexia nervosa. Neuropsychopharmacology, 41(2), 521–528. https://doi.org/10.1038/npp.2015.174

¹¹ Kerr, K. L. , Moseman, S. E. , Avery, J. A. , Bodurka, J. & Simmons, W. K. (2017). Influence of Visceral Interoceptive Experience on the Brain’s Response to Food Images in Anorexia Nervosa. Psychosomatic Medicine, 79 (7), 777-784. doi: 10.1097/PSY.0000000000000486.

¹² Zucker, N. L., & Bulik, C. M. (2020). On bells, saliva, and abdominal pain or discomfort: Early aversive visceral conditioning and vulnerability for anorexia nervosa. The International Journal of Eating Disorders, 53(4), 508–512. https://doi.org/10.1002/eat.23255

¹³ Jacquemot, A. M. M. C., & Park, R. (2020). The role of interoception in the pathogenesis and treatment of anorexia nervosa: A narrative review. Frontiers in Psychiatry, 11, 281. https://doi.org/10.3389/fpsyt.2020.00281

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¹⁹ Oberndorfer, T., Simmons, A., McCurdy, D., Strigo, I., Matthews, S., Yang, T., Irvine, Z., & Kaye, W. (2013). Greater anterior insula activation during anticipation of food images in women recovered from anorexia nervosa versus controls. Psychiatry Research: Neuroimaging, 214(2), 132–141. https://doi.org/10.1016/j.pscychresns.2013.06.010

²⁰ Fischer, D., Berberich, G., Zaudig, M., Krauseneck, T., Weiss, S., & Pollatos, O. (2016). Interoceptive processes in anorexia nervosa in the time course of cognitive-behavioral therapy: A pilot study. Frontiers in Psychiatry, 7(199), 1–9. https://doi-org.libproxy.lib.unc.edu/10.3389/fpsyt.2016.00199

²¹ Pollatos, O., Herbert, B. M., Berberich, G., Zaudig, M., Krauseneck, T., Tsakiris, M. (2016). Atypical self-focus effect on interoceptive accuracy in anorexia nervosa. Frontiers in Human Neuroscience, 10, 484. https://doi.org/10.3389/fnhum.2016.00484

²² ​​Barca, L., & Pezzulo, G. (2020). Keep your interoceptive streams under control: An active inference perspective on anorexia nervosa. Cognitive, Affective, & Behavioral Neuroscience, 20(2), 427–440. https://doi.org/10.3758/s13415-020-00777-6

²³ Berner, L. A., Simmons, A. N., Wierenga, C. E., Bischoff-Grethe, A., Paulus, M. P., Bailer, U. F., Ely, A. V., & Kaye, W. H. (2018). Altered interoceptive activation before, during, and after aversive breathing load in women remitted from anorexia nervosa. Psychological Medicine, 48(1), 142–154. https://doi.org/10.1017/S0033291717001635

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²⁵ Boswell, J. F., Anderson, L. M., Oswald, J. M., Reilly, E. E., Gorrell, S., & Anderson, D. A. (2019). A preliminary naturalistic clinical case series study of the feasibility and impact of interoceptive exposure for eating disorders. Behaviour Research and Therapy, 117, 54–64. https://doi.org/10.1016/j.brat.2019.02.004 ​​

²⁶ Zucker, N. L., LaVia, M. C., Craske, M. G., Foukal, M., Harris, A. A., Datta, N., Savereide, E., & Maslow, G. R. (2019). Feeling and body investigators (Fbi): ARFID division—An acceptance‐based interoceptive exposure treatment for children with ARFID. International Journal of Eating Disorders, 52(4), 466–472. https://doi.org/10.1002/eat.22996