Reports that eating disorder (ED) rates are rapidly increasing seem nearly ubiquitous, but are rates actually increasing? Are EDs at an “epidemic” level? I came across a recently published study suggesting that this may not be the case; indeed, ED rates might actually be decreasing, at least in the Netherlands.
In the study, Smink and colleagues (2015) followed a group of general practitioners (GPs), servicing roughly 1% of the total population, asking them to record all the newly diagnosed patients with anorexia nervosa (AN) and bulimia nervosa (BN) between 1985-1989, 1995-1999, and 2005-2009. They were interested in whether incidence rates changed or remained stable over time.
Incidence refers to the number of new cases of a disease or disorder in a population over a certain time period; it is not the same as prevalence, which refers to the total number of individuals suffering from the condition at a given point in time … Continue reading →
In 1967, Routtenberg and Kuznesof reported a very peculiar phenomenon in rats:
They discovered that when rats were on a restricted feeding schedule (1 hour per day in their experiment) and had free access to a running wheel, their food intake was significantly lower than in control rats, which were on the same feeding schedule but without access to a running wheel. This discrepancy between increased running activity and decreased food intake caused substantial body weight loss, and if rats were not removed from the experimental setup timely, they would eventually die of starvation. This model, later named the activity-based anorexia (ABA) model, is one of the most widely used animal models for the study of anorexia nervosa (AN). (Source)
Of course, rats are not humans. Nonetheless, animal models of anorexia nervosa can inform us of some of the underlying neuropsychological and physiological influences and consequences of … Continue reading →
When most people think of bulimia nervosa, they think of binge eating and self-induced vomiting. While that is not incorrect, it is not the full picture either. In the current edition of the Diagnostic and Statistical Manual (DSM-IV), there are two subtypes of bulimia nervosa: purging (BN-P) and nonpurging (BN-NP). The difference lies in the types of compensation methods: patients with BN-P engage in self-induced vomiting, or the misuse of laxatives, diuretics, or enemas whereas patients with BN-NP use fasting or excessive exercise to compensate for binge eating.
How common in BN-NP? It is very hard to say. A small population-based study in Finland (less than 3,000 participants) found that 1.7% of the sample that bulimia nervosa, 24% had BN-NP (or 0.4% of the entire sample) (Keski-Rahkonen et al., 2009). (I couldn’t find much else on prevalence of BN-NP.)
Unfortunately, however, there’s been very little research … Continue reading →
The link between urban living and mental disorders such as schizophrenia and depression has been known for quite some time (Sundquist et al., 2004). In one study, Sundquist et al found that individuals living in a densely populated area had a 68-77% higher risk of developing psychosis and 12-22% higher risk of developing depression.
The question then arises, do eating disorders follow a similar pattern? And if yes, what are some possible explanations? Certainly we know that both genetic and environmental factors are involved in the development of eating disorders, but what specific factors and to what extent remains unclear.
In this study, Gabrielle E. van Son and colleagues set out to explore whether increasing urbanization was an environmental risk factor for the development of eating disorders.
In order to answer this question, the researchers had a network general practitioners (GPs) record each newly diagnosed case of anorexia … Continue reading →
Six month of blogging and I have yet to do a proper post on the prevalence of eating disorders. I think it is about time. I see all sorts of numbers thrown around, often depending on the purpose of the article and the author’s bias. Is it 1 in 1000, 1 in 100, 1 in 20 or maybe even 1 in 2? Who is right?
Well, it is a tricky question to answer.
The number depends on how the particular study was conducted. Here are some factors that may influence the final rates: the population being studied, the sample size, the definition of eating disorder, the methods used by researchers to identify and screen for individuals with eating disorders, the number of years over which data is collected, and so on. In other words, a lot! That’s why in order to get a better sense of the true … Continue reading →