Anxiety, anorexia, and estrogen: Interpret the links with care
Some research that’s been making the rounds online, as well as on Twitter and Facebook, is the reports of a recent finding that showed an estrogen patch decreases anxiety in AN. It sounds great on the surface: anxiety is a big factor in the development and prepetuation of anorexia, so finding something that would decrease that would be great.
Which is very true, as far as it goes.
The problem is that the press releases and news coverage of the findings, if you dig and bit further and connect the dots between several different stories, doesn’t support much of the enthusiasm and optimism I’ve seen.
Sorry- I’m a scrooge like that, I guess. Bah humbug.
So I thought it would be good to take a walk through the research and share what the researchers found and (more importantly) what they didn’t find.
First things first, a few notes:
- This study was not published in a research journal. This is important for several reasons: I don’t have all of the details of what the researchers did, so my analysis won’t be as good or as complete as it might be if I had the data in front of me. As well, the article didn’t go through the peer review process. Certainly, it was reviewed by endocrinologists since it was presented at an international meeting, but I’m less familiar with that particular process.
- Estrogen treatment and birth control are not the same things. I know of several people who commented that birth control made them more anxious in response to these study results. That may be true, but oral contraceptives are generally either a combination of estrogen and progesterone OR progesterone-only.
So, now that we’re done with that, let’s dig into what the scientists did.
A team led by Madhusmita Misra, an endocrinologist at Massachusetts General Hospital, started with 72 adolescent females between 13-18 who were diagnosed with AN. Half of these girls received estrogen and half placebo. They were followed for 18 months. At the beginning and the end of the study, the participants were given questionnaires to measure state and trait anxiety (generally speaking, state anxiety is how anxious you are right now and trait anxiety is your overall personality and how anxious you are in general), as well as body shape perception.
By the end of the study, half had dropped out. It’s pretty standard for an AN study to have half the participants fail to complete the study for whatever reason (it’s why research trials into AN are so difficult to complete- patients get anxious and just bolt), but the dropout rate is still REALLY high and it definitely limits what the researchers can figure out from the data they do have. The researchers were left with 20 on estrogen and 17 on placebo. A quick glance at the numbers didn’t seem to indicate that either group was more likely to drop out.
Those adolescents given the estrogen had significantly lower trait anxiety at the end of the study compared to the placebo group. State anxiety also appeared to decrease, although they researchers didn’t have enough participants left to determine whether that was a fluke of the people who were recruited or whether it was an actual effect of the estrogen.
Interestingly, the estrogen had ZERO effect on the participants eating attitudes, behaviors, or body image. If weight gain did occur, however, the estrogen appeared to prevent a worsening of body image. It is unclear how many study participants gained weight over the course of the study, nor were other measures of recovery included in the analysis.
“Identification of therapies that reduce the tendency to experience anxiety and reduce body dissatisfaction with weight gain may have a major impact in reducing relapse,” Misra said in a press release. “These findings have the potential to impact therapy in anorexia nervosa with early implementation of estrogen replacement in girls who are estrogen deficient.”
The decrease of anxiety is really important, and really positive. But the problem is that it didn’t appear to have any effect on AN in particular, which was the whole point of the study. If the lower anxiety led to improvements in outcome, then that would be really exciting. Or even improvements in ED psychopathology or body image issues. Researchers need to do a follow-up study to see if that decrease in anxiety can be leveraged to make meaningful behavioral changes. As well, the idea that estrogen might help reduce relapse rates is interesting, but again, it needs to be followed-up to see whether this is actually true or just a good idea.
It’s interesting and promising, but I’m not sure I’d call it a “breakthrough.”
Edited to add: The study has since been published. You can read it here.