I don't think CBD has cognitive side effects, though maybe THC does. Anyway, I have not had success with CBD to treat tremors. It only made me feel a little less annoyed by them. However, when I combine CBD and THC, I do feel a sense that they are mellowed somewhat. I don't like the idea of taking that combo on a regular basis though. So I only do it when I am very stressed out. Takes the proverbial edge off.