They most certainly can..

I had meds that worked very well imo for a year. Then something got messed up.. and they don't seem to work now.... So I dunno if that counts..

But what I DO know counts are the meds I have now which I am supposed to take when "in need"... I take them basically when I feel suicidal. They work great. After half an hour I am much calmer and can sleep and such. They barely give me any side effect too.

I am hoping to get something new for long term or go back to the old ones I had... maybe they work better now..

You know... if a med did work very well that person wouldn't really have any reason to still be on this forum... right? So maybe there are more successful medications than what it seems there are here.