Similar to Lester's (2009) research, Miller et al. (2025) found that it is essential to target both BPD and ED if the patient is to make a full recovery. These researchers found that by shifting focus to and from both disorders consistently, recognizing the BPD pathology, and holding the belief that recovery means resolving both disorders, improves their chances of recovery. One participant described her experience as that of a whack-a-mole; she would take down an ED symptom, but then another BPD symptom pops up, encouraging certain coping mechanisms (Miller et al., 2025). Lastly, participants emphasized that if one symptom that coexists in both disorders is treated, that does not necessarily mean that there will be improvement in both disorders, especially if you are only looking at the symptoms from one perspective, such as an ED perspective.

Saint Olaf College

Miller et al. (2025) published a fascinating article on their research, which included qualitative data from 14 of the participants who were diagnosed with both borderline personality disorder (BPD) and an eating disorder (ED). Before discussing their findings, they elaborate on the fact that hospitalization, self-harm, and suicide attempts occur more often in patients with both disorders rather than one or the other. As a result, it is beneficial for clinicians to gain insight into their experiences, thereby expanding treatment options in an eating disorder rehabilitation center. 

They found five central themes throughout their qualitative data collection:

- The central role of emotions in the relationship between EDs and BPD.
- Perception of BPD in ED maintenance and treatment. 
- Relational dynamics faced by patients during treatment. 
- A feeling that treatment was “never enough.” 
- The importance of addressing ED and BPD symptoms simultaneously.

Lived Treatment experiences: The Complexity and Clinical Impact of having both an Eating Disorder and Borderline Personality Disorder.

Costa, J., Marôco, J., Pinto-Gouveia, J., Ferreira, C., & Castilho, P. (2016). Validation of the Psychometric Properties of the Self-Compassion Scale. Testing the Factorial Validity and Factorial Invariance of the Measure among Borderline Personality Disorder, Anxiety Disorder, Eating Disorder and General Populations. Clinical Psychology and Psychotherapy, 23(5), 460–468. https://doi.org/10.1002/cpp.1974

Bozzatello, P., Garbarini, C., Rocca, P., & Bellino, S. (2021). Borderline Personality Disorder: Risk Factors and Early Detection. Diagnostics (Basel, Switzerland), 11(11), 2142. https://doi.org/10.3390/diagnostics11112142
Khosravi, M. Eating disorders among patients with borderline personality disorder: understanding the prevalence and psychopathology. J Eat Disord 8, 38 (2020). https://doi.org/10.1186/s40337-020-00314-3

Dyson Tori, Thomas Susan J., Townsend Michelle L., Finch Adam, South Alexandra, Barkus Emma, Walter Emma, Mendonca Carley, Grenyer Brin F. S., Pickard Judy A. (2023). Salivary testosterone and cortisol levels in borderline personality disorder before and after a 12-week group dialectical behavior therapy intervention. Frontiers in Psychology, 14(14). https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2023.1195187

Federici, A. (2009). Dialectical Behaviour Therapy for the Treatment of Eating Disorders. NEDIC, NEDIC Eating Disorders Bulletin.

Lee, K. S., & Vaillancourt, T. (2024). Trajectories, comorbidity, and risk factors for adolescent disordered eating and borderline personality disorder features. Development and Psychopathology, 36(4), 1546–1557. doi:10.1017/S0954579423000792

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Lester, R. J. (2009). Brokering Authenticity: Borderline Personality Disorder and the Ethics of Care in an American Eating Disorder Clinic. Current Anthropology, 50(3), 281–302. https://doi.org/10.1086/598782

Miller, A. E., Hotte-Meunier, A., Bain, T., Macdonald, E. P., Steiger, H., & Racine, S. E. (2025). A Qualitative Study of the Lived Treatment Experiences of Women With an Eating Disorder and Comorbid Borderline Personality Disorder. The International journal of eating disorders, 58(5), 860–867. https://doi.org/10.1002/eat.24390

Navarro-Haro, M. V., Botella, C., Guillen, V., Moliner, R., Marco, H., Jorquera, M., Baños, R., & Garcia-Palacios, A. (2018). Dialectical Behavior Therapy in the Treatment of Borderline Personality Disorder and Eating Disorders Comorbidity: A Pilot Study in a Naturalistic Setting. Cognitive Therapy and Research, 42(5), 636–649. https://doi.org/10.1007/s10608-018-9906-9

Newton, J. R. (2019). Borderline personality disorder and eating disorders: a trans-diagnostic approach to unravelling diagnostic complexity. Australasian Psychiatry : Bulletin of the Royal Australian and New Zealand College of Psychiatrists, 27(6), 556–558. https://doi.org/10.1177/1039856219852297

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Reference List: Comorbidity of Borderline Personality Disorder and Eating Disorders

All of the researchers' participants believed that their ED was merely an outlet for their BPD. Since BPD makes one feel out of control, the ED, one said, “gives you drive, it gives you… a goal… With BPD, you feel like you're so out of control all the time” (Miller et al. 2025). Not only does this provide a priori evidence for individuals who may struggle with both BPD and ED–BPD is more likely to arrive first–but it also suggests that BPD is often a force that is very far outside of their control. It is not that they wish to struggle with emotional regulation, indecision, or self-destruction.

Perception of BPD in ED maintenance and treatment. 

Miller, A. E., Hotte-Meunier, A., Bain, T., Macdonald, E. P., Steiger, H., & Racine, S. E. (2025). A Qualitative Study of the Lived Treatment Experiences of Women With an Eating Disorder and Comorbid Borderline Personality Disorder. The International journal of eating disorders, 58(5), 860–867. https://doi.org/10.1002/eat.24390


A Qualitative Study of the Lived Treatment Experiences of Women With an Eating Disorder and Comorbid Borderline Personality Disorder.

One common theme of participants struggling with both BPD and EDs was working in an environment with several others. They were easily irritated and had several interpersonal conflicts (Miller et al. 2025). On the other hand, participants also highly valued their relationship with their therapists. Thus, as often is the case with BPD, if they placed their trust in their therapist and the therapist did not meet their expectations or made a mistaken promise, there was turmoil in the relationship, but also in the participant’s recovery (Miller et al., 2025). 	

Relational dynamics faced by patients with both BPD and ED during treatment.

Currently, there are several ethical concerns regarding care for participants with both eating disorders and BPD and pathology. For instance, there is a high relapse rate for these individuals, who will often struggle with ED behaviors on and off for the remainder of their lives. The Miller et. al. (2025) research offers qualitative insight into the why behind these relapses. All 14 of their participants express their fear of relapse after treatment and acknowledged that they will likely resort to ED behaviors because, without the safety net a therapist provides, they begin to feel hopeless and out of control, so the ED behaviors comfort them (Miller et al. 2025). One participant stated, “I see myself relapsing… so that I'll get referred back to the [ED Clinic] because like I can't be without, like, anything at all… my brain can't compute that, like to just be completely on my own… I don't feel safe.” (Miller et al., 2025). This research shows that there needs to be a change in either the treatment process or the accessibility to treatment. 

A feeling that treatment was “never enough.”

Lester, R. J. (2009). Brokering Authenticity: Borderline Personality Disorder and the Ethics of Care in an American Eating Disorder Clinic. Current Anthropology, 50(3), 281–302. https://doi.org/10.1086/598782

Brokering Authenticity: Borderline Personality Disorder and the Ethics of Care in an American Eating Disorder Clinic. Current Anthropology

Current research on the comorbidity between both disorders agrees that the eating disorders' pathologies are often a means to cope with emotional distress, and Miller et al. (2025) find this to be true in their research as well. However, they also add that targeting these emotions is critical to treatment. 
One participant interestingly emphasized that binging, purging, or restricting are the only methods that ever provided some form of comfort. Other emphasized the importance of exploring emotions and appreciated the days they had Dialectical Behaviorial Therapy. The aspect they enjoyed the most was the fact that they were able to understand and related to others through DBT, finding a sense of comfort and confidence in emotion regulation. Additionally, one participants discussed how other ED focused treatment did not use emotion focusd langage and instead said, “you eat your lunch” rather than what this participants thought to be more helpful “what are you living or what are you feeling right now” (Miller et al. 2025).


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