Psychology of Bulimia: Similarities with Borderline Personality Disorder

The Only Constant Is Change

As Aimee Liu writes in her powerful book, Gaining: The Truth About Life After Eating Disorders, a key component often found in the psychology of bulimia nervosa is the need for near-constant change: For some with a history of bulimia, it's difficult to remain with anything for long, because everything (from expensive possessions, i.e., vehicles, to friends to wardrobes) gets changed routinely. Some suggest that there is an unspoken hope that in the midst of all the changes, some new thing will be the magic bullet that "fixes what ails."

Psychotherapists recognize that this sort of restlessness can be a symptom of lots of other disorders. One disorder that stands out in its overlap with the behaviors of bulimia, though, is borderline personality disorder, or BPD.

Psychological Parallels Between Bulimia and Borderline Personality Disorder

BPD is a chronic and hard-to-treat problem that is characterized by instability with emotions, self-image, and behaviors. A person with BPD treats personal relationships in much the same way that a person with bulimia treats food. In one moment, a new acquaintance is "perfect" and immediately becomes a "best friend," but as soon as there is any sense that the new friend can't meet all the needs the person with BPD has, the friend is as good as dirt.

It's perhaps not surprising that BPD is the most common personality disorder found in those with bulimia nervosa: Estimates of the fraction of those with bulimia who also struggle with BPD range from 9% to 25%.

Psychology of Bulimia and BPD: Rejecting the Desirable

For the person with BPD, a key need is a relationship that is consistent and nurturing. Often, a person with BPD has found chaotic and destructive relationships where the most nurturing relationships should be. Therefore letting someone get emotionally close presents a dilemma: Is this person going to be a wonderful friend or may this person also be a dangerous betrayer of some kind? For a person with BPD to feel safe, a potential friend who begins to get close is often rejected.

I think of bulimia in similar ways. For the person with bulimia, the obvious need is digested food. Food is clearly desirable and satisfying (otherwise, why binge on it?), but it also seems that wherever food is, there is something "bad" that must be avoided. The person assumes that food will do serious damage to the body (through making her fat). So she treats food as a person with BPD would treat a friend: Once the food gets too close (at the point of being digested), it's rejected.

In both cases, rejection occurs out of the fear of being hurt, and in both cases, the rejection itself results in being hurt: loneliness (and other symptoms) in BPD, and physical problems (and other issues) in bulimia.

Relationship Similarities Between Bulimia and BPD

It's been my clinical experience that those with bulimia have similar relational dynamics (the ways in which they interact with other people) to those with BPD, although to lesser degrees. For example, a person with bulimia may demonstrate a huge desire for intimacy in some area of life, while at the same time avoiding it religiously. It can also manifest in the treatment relationship between counselor and client: The client can want to be seen (and nurtured) by the therapist, while clearly being afraid of being seen (and harmed).

One Treatment That May Address Both Bulimia and BPD

Treating bulimia is vastly different from treating BPD, yet it's not surprising that a therapy called dialectical behavior therapy, first developed for BPD, is now being investigated for use with bulimia (and binge-eating disorder as well). This therapy is designed to help with regulation of emotions, so that there is less of a need to be reactive to things that happen — either good or bad. The basic theory is that the emotions drive the problems, and when these emotions come under control through concrete behavioral techniques, the disorder comes under control as well.

Points to Remember

Not everyone with bulimia has BPD; nor does everyone with BPD binge and purge. The similar dynamics between them, though, makes them not an uncommon match, and I believe that understanding one helps in understanding the other.

For a person with bulimia who is beginning a course of eating disorder treatment, it may be helpful to know beforehand that there will likely be worries about whether people care and also discomfort when they get close. Pushing through these feelings can lead to powerful healing.