If I change medication and decide to go back to my old med will I have to titrate again?

hi!

I am currently on concerta 36, and I really don’t know how to feel about it. I don’t feel any difference between 27 and 36

at my last appointment my psych said that if concerta 36 didn’t help we would try a new medication

so if I try this new medication and decide to go back to concerta would I have to start with 18 again?…

thanks!