Okay, I would like to chime in here. Please bear with the long post, but I have some personal experience with ADD meds and pregnancy/nursing that I would really like to relate.
I am a mom of a twelve year old boy and one year old daughter. My son was born before I was diagnosed with ADD and I nursed him until almost two. I love the bonding, and the benefits of BF'ing are amazing, so of course when my daughter was conceived two years ago I fully intended to breastfeed.
However, this was after I had been diagnosed and had been treated for ADHD and anxiety disorders and had been well controlled on medication for years. Because I was nervous about the effects during pregnancy, I tried to cut out all my meds (other than zoloft) at the advice of my OB/GYN. It was a disaster.
I was in online school and in one month went from an A average to a D-. My son was worried about me because I was so on edge and unable to cope that he actually would come home from school, help clean the house, and would give me a dozen hugs a day trying to make me feel better (I have an awesome son
I hated that he felt he needed to take care of me, and that of course made things worse. When I went to my OB/GYN appointment next time, she was very concerned in the changes in me and recommended I go back on my ADHD meds at a reduced dose, as well as giving me a very low dose emergency prescription for Xanax in case of severe anxiety attacks.
She explained to me that while the restriction on these meds are primarily precautionary, since studies on them aren't conclusive, the studies of the effects of massive stress ARE well documented and that can be devestating to an unborn baby's health. So I began taking my medication, sparingly and only when absolutely necessary, and my stress levels quickly became much more manageable. My doc was happy because she felt the meds were a much lesser risk than the constant panic attacks and depression my untreated ADD and anxiety was causing.
After the baby was born, I was of course planning to nurse, but now the medication question popped again. I talked with the pediatrician, my OB/GYN, psychiatrist and GP about staying on my reduced medication schedule nursing. My OB/GYN was supportive, as was my psychiatrist, and surprisingly, my pediatrician. The only one who was not was my GP, who felt it was an unnecessary risk. I decided it was three to one, particularly because my pediatrician told me she firmly believed that small amounts of the medication in breast milk did not pose any real risk (as long as there was no sensitivity) and that the negative impact of me losing my ability to function well was far more serious as a risk. She is a big breastfeeding proponent, and in her opinion even with the minute amount of med that might pass into the milk breast milk was still the far better choice when compared to formula.
So, long story finally to a close, my daughter is one year old now and still nursing. I take my ADD meds when needed, even have moved up a bit towards my previous most effective dosage. All docs have been monitoring me and my daughter, and I am thrilled to say we are both doing well. She is a bright, beautiful, healthy girl who has never had any health problems at all. She is perfect (I may be biased) and I am very comfortable with my decisions. My husband has been awesomely supportive through this all as well.
With proper medical supervision, I think that the benefits of the medication can outweigh the risks...as I said, stress is clinically PROVEN to cause major health problems for unborn children and there are so many amazing benefits to breastmilk that even with the (very very small) risk of nursing while taking ADD meds it is still is superior to formulas - the immunities passed along, milk that changes to meet baby's needs as they age so their food is always custom-perfect, the lowered risk of future obesity, and so many other benefits are all amazing!
As long as you are open with your doctors so that they can monitor you and the baby, I believe you nurse safely while maintaining a modified medication regimen. And remember, if your doctor is very much against it, you can always look around for a second opinion, and my psychiatrist said that more than once he has called ob/gyns and pediatricians to consult with them about acceptable medication regimens. Maybe you could talk to your doctors about something like that.