The Link Between Two Challenging Illnesses: Borderline Personality Disorder and Eating Disorders

By Melissa O’Neill, LCSW, Director of Program Development at Timberline Knolls

Certain psychiatric disorders are easier to understand and diagnose than others. If a young girl is drastically underweight and every other medical condition has been ruled out, anorexia is probably the issue. Similarly, if an adolescent boy cannot find the energy or desire to get out of bed each day, depression is easily suspected.

Borderline Personality Disorder (BPD) often proves a little more challenging.  Fortunately, this illness is frequently characterized by two fairly identifiable features. First, those with BPD often develop ingrained push-pull habits regarding interpersonal relationships. This means “I love you,” and “I hate you,” can show up in the same conversation. The second component manifests more in the sphere of emotionality. Not only can moods change very rapidly, but they experience emotions very intensely. This is referred to as rapid affective dysregulation.

The groundwork for BPD begins in the child and adolescent years primarily as a result of early developmental trauma.  Neglect, ongoing invalidation, abuse from an authority figure can all contribute to the onset of BPD in the twenties. Essentially, the person experienced a host of negative behaviors during formative years, then ultimately adopted them as their own.

Because of their relational instability and emotional volatility, what they fear most, abandonment, often results, which leads to pain and isolation. It comes as no surprise that those with BPD often have co-occurring disorders such as substance use disorder (SUD) and eating disorders (EDs). As with all maladaptive coping techniques, these strategies will work for a while.

Alcohol and/or chemical substances can figure prominently as a method to cope with the pain of broken relationships or dysregulated emotions. The manipulation of food serves a similar purpose. Interestingly, unlike a classic scenario in which a person is firmly committed to a specific ED, someone with BPD will frequently shift from bulimia behaviors to anorexic practices, back and forth.

When experiencing a high-level emotionality, solace can be found in bingeing and purging. The consumption of food provides a distraction, while the act of purging provides emotional catharsis as well as endorphin release from the brain.  Restricting food also works, especially over time. Starvation has its own “rewards” in terms of slowing down cognitive processes.  For an individual governed by impulsive thoughts, extreme food restriction reduces impulsivity, allowing a state of cognitive disconnect to ensue. SUD and ED behaviors can also occur at the same time, for example, high alcohol consumption and food restriction.

Although BPD is a complex and challenging disorder, it can be overcome. An individual can learn new strategies to break the cycle of emotional dysregulation and discover how to function in a healthy interpersonal relationship.