my sons doc changed his meds from ritilin to concerta about 4yrs ago his health has been fine he is less wound up at night and he doesnt get quite so much paranoia recently like others have said its a time release med so son is on two tabs a day, he takes them just before his breakfast within an hour he is such a pleasant boy and the anxiety he was experincing while on ritilin has gone, he still doesnt eat a lot as with ritilin concerta supresses his appetite but he makes up for this when the med wears of in the evening, he also can take risperdol at night to help him sleep, like everyone else says each med efects ppl diferant but allways find out as much as you can about the med first