Most of the patients I have treated for Bulimia Nervosa over the years have experienced symptoms typical of impulse disorders. An impulse disorder is simply the inability to resist the impulse to steal (kleptomania), gamble, use drugs, lie about activities, and etc. What is so impressive about these symptoms is that they are associated with people who otherwise are intelligent, high achieving and have good judgment. In none of the many people I have seen with Bulimia Nervosa have anyone believed that there was anything wrong or immoral about their behavior. I should quickly note that not all people with Bulimia engage in these activities. However, it has been my experience that many do engage in at least one of them. In addition, the activity of theft was always petty and totally unrelated to economic need. Whether theft or otherwise, the patients all had ways of justifying what they did. These justifications were unshakeable.
It is unclear why this happens with people who have bulimia except that it must be part of some form of difficulty controlling impulses. For example, those with bulimia cannot resist the urge to binge when they feel overwhelmed by that impulse. In the same way, they experience a similar purge after the binge is over. Similarly, they feel they may feel an impulse to steal a small item when in a store, a wish to sneak into another movie in a multiplex after having paid for the first movie or use marijuana, alcohol or another drug to feel better.
In all cases, there is a need to be secretive and never admit what they have done. In the context of psychotherapy, people have admitted to these activities. In the case of bingeing and purging there are overwhelming feelings of shame that motivate extreme secrecy. Shame does not seem to be the motivating factor behind the other impulsive activities.
It is important to point out that purging affects the same parts of the brain that are affected by drug abuse. In actuality, purging becomes addictive just the same as drugs of abuse. It may seem counter intuitive to those who do not purge to know that there are intense feelings of pleasure and relief experienced by the bulimic after the purge. In the same way there are intense feelings of pleasure experienced by the drug abuser. It is the memory traces set down on the neurons in the pleasure parts of the brain that make it so difficult for the bulimic and drug abuser to stop the activity.
One advantage the bulimic has over those addicted to drugs is that the feelings very quickly turn from pleasure to intense self hate and deep depression after the binge purge cycle ends. That self hatred and depression become good motivating factors for many people with bulimia to seek help and learn how to end the cycle.
It could just be that the binge purge process, along with minor theft and alcohol or drug abuse are all attempts to self treat depression. Paradoxically, these very activities, especially the binge purge cycle, reinforce self hate and depression.
Finally, it has also been my experience that all of these impulsive activities end when patients gain control over the way they eat and, thereby, end the purging. The better able a person is to fight the impulse to purge, the less frequently will they engage in the purge. Gradually, the need to purge decreases bringing with it increased self esteem and decreased depression. The help and support of a therapist and nutritionist, both trained in eating disorders, is an excellent way to bring this condition under control and, with it, all the other impulsive activities.