I've taken Deplin for about 7 months. I think it has had some positive effects, but I'm not 100% sure because a lot has been going on in those months and it is hard to know what is what. The reason that I started on Deplin was that I have serious problems with depression (BP II), but I was trying to minimize meds due to trying to get pregnant. The bonus with Deplin for this purpose is that it is a form of folate and folate is very important to a healthy pregnancy. I do think it helped me keep my lamictal dose down.
Also, my pdoc apparently gets a lot of samples, so I have yet to pay for it.
Best,
EJ