Ritalin is used for ADD and ADHD. It is a stimulant and is often calming in patients with ADD/ADHD. However anxiety and ADHD are the same illness, at least from a cannabis perspective.
I would usually advise starting the whole plant CBD, perhaps long acting such as a capsule with CBD. Then, over a week or two, begin tapering the ritalin, as stimulants are just not a great idea to use long term. Also, CBD is a great therapy for ADHD/ADD