Eating disorders are notoriously difficult to treat, so recent research in the field has focused on how we can predict and improve treatment outcomes. People diagnosed with eating disorders have all kinds of different traits and temperaments. Traits like harm avoidance and high self-control are associated with anorexia, while traits like impulsivity are associated with bulimia (Bjork et al., 2003). And across eating disorders, self-attack is a common theme. Is the variability in treatment outcome among different eating disorders due to the disorders themselves, or the traits of the people who tend to develop certain eating disorders? Do people with different eating disorders tend to differ in their self-image, and could these differences predict treatment outcome?
A group of Swedish researchers ran a study with 2221 adult females diagnosed with an eating disorder to find out how their scores on an assessment of self-image at the start of treatment might predict their treatment results. 457 women in the study had Anorexia–Restricting Subtype (AN-R), 228 had Anorexia–Binge/Purge Subtype (AN-BP), 861 had Bulimia (BN), 505 had an Otherwise Specified Feeding/Eating Disorder (OSFED), and 107 had Binge Eating Disorder (BED). All patients completed a comprehensive assessment prior to starting treatment that included a measure called Structural Analysis of Social Behavior (SASB), as well as the Eating Disorders Examination Questionnaire (EDE-Q).
The Structural Analysis of Social Behavior assessed the patients’ self-love, self-affirmation, self-protection, self-control, self-attackm self-blame, and self-neglect.
12 months later, the patients were assessed again with the EDE-Q and SASB. Their BMIs and level of impairment from their eating disorder symptoms were also assessed.
For patients with AN-R, higher self-love and lower self-blame predicted a positive outcome after treatment. How did the researchers define “positive outcome”? With anorexia, it’s tough to pin down this variable. In this study, the researches said absence of eating disorder diagnosis at 12 months. In other words, if a patient no longer met the criteria for their eating disorder diagnosis as defined by the Diagnostic and Statistic Manual of Mental Disorders- V (DSM-V), it was considered a positive outcome.
For patients with AN-B/P, lower self-neglect predicted absence of eating disorder diagnosis at the 12 month follow-up. For BN, lower self-attack at the initial assessment predicted absence of diagnosis at the 12 month follow-up. In the OSFED group, lower self-blame at the start of the study predicted absence of diagnosis after 12 months. Interestingly, people with BED had the same chance of having a positive treatment outcome no matter what their levels of self-blame, self-attack, self-love, and self-control were.
Other variables predicted patients’ treatment outcomes as well. For both types of anorexia, higher BMI at the start of treatment was associated with better outcome. The same was true for patients with bulimia. For patients with either bulimia or OSFED, fewer initial psychiatric symptoms (not just eating disorder symptoms) predicted better treatment outcome. And for patients with BED, score on the EDE-Q (just eating disorder symptoms) was the best predictor.
What do these results mean for eating disorder treatment?
The researchers found that high self-protection and high self-control predicted worse treatment outcome in patients with AN-R, AND these findings were unique to AN-R. They suggest that patients are seeing anorexia as a form of protection and are often resistant to let it go. The denial that is so unique and so puzzling in anorexia seems represented in their findings. They stress the importance of separating the “anorexic self” from the “authentic self” in treatment for this eating disorder.
Patients with binge/purge subtype of anorexia differ from those with restricting subtype in a key variable: self control. For patients with B/P subtype, high self control at initial assessment actually predicted better treatment outcome. The researchers say patients with higher self-control may adhere to their treatment plan better than more impulsive patients and so, at 12 months, may not be engaging in impulsive binge/purge behavior. However, we see a very interesting result when AN-B/P patients are assessed after 3 years (Birgegard et al., 2009). AN-B/P patients who were higher in self-control at the start of their treatment seemed to experience a remission by 12 months, but by 3 years had often relapsed.
For treatment providers, these findings highlight the fact that an AN-B/P patient’s initial adherence to their treatment plan during the first year of their treatment actually does not predict their chance of long-term recovery.
Patients with BN often showed high self-neglect and high self-attack, so the researchers say self-compassion training may be especially useful in treating BN. Emotion regulation skills could also be important because people with BN often have another diagnosis like borderline personality disorder, which is associated with self-harm.
Finally, the researchers say that people with BED do seem to show lower self-esteem compared to healthy people and obese people. So low self-esteem may be a key target for their treatment.
This study shows the different traits associated with different eating disorders and might shed some light on the reasons for why certain diagnoses respond differently to therapy than others do. Hopefully, future research can tell us more about the particular variable of a person’s self-control, and whether a patient’s treatment should address impulsivity or over-control.
References:
Birgegård A, Björck C, Norring C, Sohlberg S, Clinton D. Anorexic self-control and bulimic self-hate: differential outcome prediction from initial self-image. Int J Eat Disord. 2009;42(6):522–30.
Björck C, Clinton D, Sohlberg S, Norring C. Negative self-image and outcome in eating disorders: results at 3-year follow-up. Eat Behav. 2007;8(3):398–406.
Forsén Mantilla, E., Norring, C. & Birgegård, A. Self-image and 12-month outcome in females with eating disorders: extending previous findings. J Eat Disord 7, 15 (2019).