Q&A with Jean Forney- Answering Important Questions about Purging Disorder
Researchers are beginning to study the full spectrum of eating disordered behavior, which extends far beyond the more common diagnoses of anorexia, bulimia, and binge eating disorder. One of these potential disorders is purging disorder.
PhD candidate Jean Forney wants to study purging disorder as part of her dissertation, but she needs your help to raise the funds to complete her study. She was gracious enough to agree to do a Q&A with me about purging disorder, her study, and how you can help contribute.
1) Can you tell me a bit about yourself and your background?
I am in the dissertation phase of my PhD in Clinical Psychology at Florida State University (Go Noles!) My advisor is Dr. Pamela Keel, the woman who named purging disorder. She is a phenomenal advisor for my dissertation on the long-term outcome of purging disorder. I completed my undergrad in psychology at Miami University in Oxford, Ohio. I’ve been interested in eating disorders since I was an undergraduate and completed a summer internship at the University of Chicago Eating and Weight Disorders Program. Throughout my career, I plan to continue researching eating disorders to better understand what maintains them. By understanding what maintains eating disorders, we can develop even better treatments.
2) What is purging disorder? How is it different from anorexia, bulimia, binge eating disorder, and EDNOS/OSFED?
Purging disorder is an “Other Specified Feeding or Eating Disorder” in the Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5). It is defined by recurrent purging to influence weight and shape in the absence of binge-eating episodes. Purging behaviors include self-induced vomiting, laxative misuse, and diuretic misuse. Purging disorder is different from Bulimia Nervosa and Binge Eating Disorder, because individuals with Bulimia Nervosa and Binge Eating Disorder experience recurrent binge-eating episodes (eating an unusually large amount of food, like an extra large pizza, while feeling out of control), whereas individuals with Purging Disorder do not experience binge-eating episodes. Purging disorder is different from anorexia nervosa, because individuals with purging disorder are at a normal weight or overweight.
3) Do you know how common purging disorder is?
Estimates vary, with the highest estimates suggesting that up to 5% of women experience purging disorder in their lifetime (Wade et al., 2006). Other estimates of lifetime prevalence up to age 20 are around 2-3% (Allen et al., 2013; Stice et al., 2013). That means about 2-3% of women experience purging disorder by the time they are 20 years old. This is comparable to the prevalence of bulimia nervosa. There is less data on prevalence in boys/men, and so far it appears that less than 1% of adolescent boys experience purging disorder (Allen et al., 2013).
4) How does it appear to impact a person’s life?
Purging disorder can affect all domains of someone’s life. Most research suggests that purging disorder is just as severe and impairing as bulimia nervosa. Individuals with purging disorder report more suicidality than individuals without eating disorders and have elevated mortality rates compared to the general population. Individuals with purging disorder tend to be more anxious and depressed than individuals without eating disorders. Of course, the complications that go along with self-induced vomiting and laxative/diuretic misuse occur in purging disorder as well—problems with the esophagus, GERD, electrolyte imbalances, etc. It affects the mind and the body.
5) Why does purging disorder deserve more study?
All of the reasons above! Purging disorder can be deadly. Problematically, because it’s not a “full” eating disorder in DSM-5, people, doctors, and therapists may not look for it. We only look for what we have a name for. Additionally, because purging disorder has only recently been named, there is relatively little research on treatment and outcome. That is changing, and research is starting to come out about the course, outcome, and prognosis. The next step is understanding treatment, and from my understanding, that research is beginning.
6) What are some of the most important questions to answer about purging disorder?
Two questions come to mind right away.
What is the prognosis of purging disorder? We are starting to get some information on adolescents in the community and adults who seek treatment at inpatient hospitals, but we don’t know the prognosis/outcome of an adult who is living in the community. We also know relatively little about what predicts outcome—things like depression, experiencing a sense of loss of control while eating, etc. Knowing that information will help us know if purging disorder is different from bulimia nervosa, and inform treatment decisions.
What treatments work for purging disorder? Based on treatments for other eating disorders, we can guess what treatments will work, but we won’t know in any sort of systematic way. It’s quite possible that treatments need to be tweaked for purging disorder compared to eating disorders with binge eating, like bulimia nervosa.
7) Do you think purging disorder should be included in the DSM-5 as a separate disorder? Why or why not?
I think we still don’t have enough information to answer this question. Just looking at people at one point in time, it looks like purging disorder is a distinct disorder from bulimia nervosa and anorexia nervosa. However, we really need to know if purging disorder and bulimia nervosa are just one disorder at two different phases, or if purging disorder is a distinct disorder with a different likelihood of remission, set of comorbid problems, etc. To answer these questions, we need to look at people with purging disorder and bulimia nervosa at multiple points of time. Clinically and anecdotally, I can tell you that purging disorder seems like a different disorder than bulimia nervosa—but I need to collect the data to prove it!
8) You’re raising funds to study purging disorder–what do you hope to learn with this study?
My study is looking at the long-term outcome of purging disorder. There are three main questions I’m asking.
1) What are the remission rates for purging disorder?
2) What predicts remission? I’ll be looking at a number of potential predictors including severity of shape/weight concerns, depressive symptoms, how often someone feels like their eating is out of control, and how large (or small) someone’s meals are. I’ll also be looking at two hormones: leptin (which is secreted from fat tissue) and cholecystokinin (which is released from the gut after you eat).
3) Does purging disorder have a different outcome from bulimia nervosa? These questions will provide much needed descriptive information on purging disorder. By looking at predictors, we will be able to identify potential treatment targets. By comparing purging disorder to bulimia nervosa, we will better understand if purging disorder should be it’s own “full” diagnosis in DSM-5, just like anorexia nervosa, bulimia nervosa, and binge-eating disorder. This will ultimately influence the likelihood that people recognize purging disorder and receive effective treatments.
To do this, I will be following up 219 women who participated in earlier studies about purging disorder and bulimia nervosa. They will be invited to complete an hour-long interview and questionnaires. Using their information, we can answer these questions.
9) How can readers contribute to your fundraiser?
I have an experiment.com page here: http://experiment.com/projects/long-term-outcome-of-women-with-purging-disorder/
Funds are really important for helping to pay participants. I will be following-up these women on average 10 years after they participated. They will be, on average, 33 years old and leading busy lives. The funds will be used to compensate them for their time. This study will only be meaningful if we can maximize the number of women who participate, and offering compensation will help greatly!