... Sleeping tablet Lunesta 3mg and Mirtazapine 30mg a day, how risky this is.

He has increased the Mirtazapine from 15mg to 30mg & Clonazepam from 0.15 to 30mg after being advised by one of Psychiatrist where he is taking some classes & not from his own Psychiatris, he didn't have any written prescription of increased dose.
How risky is this and do we need written prescription before he should start taking higher doses