"concerned"

[Hanifasmm]

Mister Micawber,
Thanks to you.
You are really great!
with regards,
Er.S.M.M.Hanifa

Concerned with/about and Concerned for/about

Hello. I know that ‘concerned for/about’ is used when you are worried and feeling concern about something, and ‘concerned about/with’ is used when you’ are interested in something, but I’m not sure in what context we use concerned for/about and concerned about/with. Please enlighten me. Thanks in advance.