East European's craziness depicted in series (8)

I believe the answer is:

rumanian

I'm a little stuck... Click here to teach me more about this clue!

'east european's' is the definition.
'rumanian' can be an answer for 'european's' (I've seen this before). I'm not sure about the 'east' bit.

'craziness depicted in series' is the wordplay.
'craziness' becomes 'mania' (I've seen this in another clue).
'depicted in' is an insertion indicator.
'series' becomes 'run' (a run or sequence of things).
'mania' placed inside 'run' is 'RUMANIAN'.

Can you help me to learn more?

(Other definitions for rumanian that I've seen before include "from Transylvania?" , "European" .)

I've seen this clue in The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.