Doctors and patients both may have a hard time determining when a new health concern is actually a side effect. That’s especially difficult when you don’t find the problem on any official list of drug adverse effects. As a result, one reader ended up wondering, “Is my depression linked to metformin?”
How Is Depression Linked to Metformin?
Q. I was recently prescribed metformin to control blood sugar. When the dosage increased from one to two times a day, I began to have serious depression.
I had experienced depression many years earlier. Then, the cause was hypothyroidism; after two weeks on Synthroid, I was a “new person.” Consequently, I knew that this wasn’t just random sadness.
I treated myself as a guinea pig, starting and stopping the medicine three times just to be sure that metformin was really the cause. Each time, it took longer to feel normal again. When I reported this to my internist, she wasn’t aware that this was a side effect.
I have found that increasing my dose of B vitamins, especially vitamin B12, helps the depression somewhat. I’ve had chronic trouble getting enough B12 since I was a teenager, but my doctor monitors my levels.
Metformin and Vitamin B12 Deficiency:
A. Metformin is the most commonly prescribed diabetes drug in the world. It works well, but it can cause vitamin B12 deficiency (Diabetes & Metabolism, Nov. 2016).
Low vitamin B12 levels have been associated with depression (Fortify Your Life: Your Guide to Vitamins, Minerals and More). Other symptoms of B12 deficiency include fatigue, numbness and tingling, sore tongue, palpitations and shortness of breath.
You might ask your doctor to request a methylmalonic acid (MMA) test in addition to your serum B12 blood test. High levels of MMA point to low levels of vitamin B12.
Ask your doctor to help you find the right dose of vitamin B12 to overcome depression linked to metformin. You shouldn’t have to feel severely depressed in order to control your blood sugar.
You may want to read more about diabetes or depression to prepare for your conversation with your health care provider. We suggest our eGuides to Managing Diabetes and Dealing with Depression for further information. If you have had a similar experience, please feel free to share it in the comment section.