I have been suffering from depression and an eating disorder for a couple of years. Although, I have been in treatment for the eating disorder and have made some progress, the depression is still debilitating and feels endless. Some professionals have told me that anti-depressants are not effective if you are at a low weight.
Has this been studied and do you believe it to be true? At what BMI do anti-depressants work effectively?
Indeed, anti-depressant medications have not been found upon formal study, to be any better than placebo, for the treatment of depression or any of the symptoms that generally improve with these medications, in patients with anorexia nervosa. We know this from studies that randomly and blindly assign patients to active medication or inactive placebo and measure symptom change, such as those associated with depression, anxiety and eating.
One study we conducted at Columbia of this nature was:
Attia E, Haiman C, Walsh BT, Flater SR. Does fluoxetine augment the inpatient treatment of anorexia nervosa? Am J Psychiatry. 1998 Apr;155(4):548-51.
The second part of your question remains challenging to answer because a recent study done by our group found an antidepressant to be no better than placebo, even when the patients reached normal weight at the time of study entry.
(Walsh BT, et al. Fluoxetine after weight restoration in anorexia nervosa: a randomized controlled trial.JAMA. 2006 Jun 14;295(22):2605-12.)
This leaves us wondering whether individuals need to be normal weight for a longer time in order to respond, or whether the target weight required for this study (BMI = 20) is not adequate for antidepressant response.
Also, it is important to remember that depression improves signficantly with weight restoration, so any treatment that can help someone move toward normal weight is worth trying as an anti-depressant strategy itself.