Q: Metformin & Weight Control
Dear Dr. Phelps,
I'm 29 years old and was diagnosed with Bipolar-I when I was 22. The illness
runs in my family, but I didn't experience my first clinically significant
episode until I developed an eating disorder at age 21. It felt like the eating
disorder somehow "triggered" the bipolar. Since then, I have
struggled with my weight and have experienced carb cravings and occassional
binging. My weight has fluctuated a lot since starting medications (at my
worst, I gained and then lost 70 pounds). Over the last 3-4 years, I have
noticed that I am tending to gain weight with increasing ease. This is true
even when I restrict calories. When I am able to lose weight, it is only with
great difficulty. I saw the information on metabolic resistance that you posted
and showed it to my psychiatrist. With some reluctance, he agreed to try
metformin both to help me lose weight (I am 5'3'' and currently weigh 147 lbs.)
and to help prevent me from gaining any more. But he requested that I ask you a
1) What have your results with metformin looked like in the 5 months since you
last wrote on the topic?
2) Have you noticed any effect on mood from metformin in patients with bipolar?
3) Roughly what percentage of your patients started on metformin have achieved
significant weight loss or have
avoided further weight gain?
I am happy to follow up by reporting to you the results of my "metformin
trial" if you would like to increase your "n". I keep a very
detailed chart of my moods, weight, and medications, which should help me
determine whether the metformin is working. BTW, I now take seroquel (400 mg),
lithium (900 mg), parnate (20 mg), synthroid (88 mcg), and lamictal (300 mg).
Dear Liz --
You have a smart psychiatrist: those are good questions I'd hope a doctor would
ask. My sample size remains small, so I'd be interested in your results if you
try this. Frankly, after about 10 patients, only two of whom have lost a
significant amount of weight, and one or two who appear to perhaps have ceased
gaining, I've started using amantadine more often. There too we have only one
open study with less than 20 people to go by. And I'd held off using it because
it affects the neurotransmitter dopamine, which in some versions of bipolar
disorder would seem like working against one's own medications, some of which
affect dopamine in somewhat opposite way. But darn if the first 4 people I
tried it on didn't start losing weight. On the other hand, all four also got a
tremor and had to reduce the dose from 300 to 200 mg, and the long term
consequences of using
this way are basically completely unknown (as well as amantidine's somewhat
higher risk profile in first place).
However, I haven't changed the metformin story
to match what you're reading here; in part because my sample is also too small
to say "it doesn't work"; and in part because of the
report from Dr. Rasgon I posted as part of the metabolic syndrome story, in
which metformin was used effectively to treat depression. There's still
something more appealing to me to try to treat the problem, which it
seems metformin has the capacity to do, though admittedly not every time; as
opposed to amantadine, which as far as we know is just adding another
medication with some sort of funny side effect of weight control (rather like
the Topiramate strategy).
Another similar "report from the fringe"
would be to look at using T3/T4 thyroid, which has no clear data supporting its
use (not even the less-than-20 open trial data), but again some metabolic
rationale as discussed in
Bipolar. Careful not to freak out your doc' with too many of these reports!
Good luck to you.
Published December, 2003