hi,i have severe arthritis pain,and herniated disks in my lower back.i recently started taking ritalin awile back for adhd problems and depression.i would like to know if there is any connection between taking central nervous system stimulants,such as ritalin, and having increased pain? i have been in horrible pain for the last couple of weeks, and if there is any connection,i will change meds. please, if any knows any thing about this, please respond!