Might help to contact a naturalist who specializes in homeopathic remedies. I know my Cymbalta pharmacy info specifically contraindicates St. John's Wort because it is another form of anti- depressant. I'm also on Neurontin, but haven't seen anything on the reaction between it and SJW.. My doctor told me NOT to take SJW with my Ultram because it also has some anti-depressant properties, so knowing that it can react with some of our meds, I would wnat a professional opinion.
Another note. I have a friend who is VERY into natural remedies (she has allopecia). She uses a certified naturalist and was told that St. John's Wort is not very effective for a large majority of people. Her daughter didn't have any real results with it either. She said that SAM-e and Kava kava have been shown to have more results than the St. Johns Wort.
Hope this helps. Good luck.