Stonekeeper's Vacation Game: Guess a movie #10 [FredBurroughs wins]

Stonekeeper's Rules:

So you guys like to play games? This is my favorite one that we use to play on Imdb. It's a investigating game that can be time consuming but it's lots of fun. Basically, I have a movie in mind and you have to guess movies. For each movies you guys are going to guess, I will give a hint that connects the two movies. Example: Actor, lenght, genre, aspect ratio, language, country, year, director, writer in common, rating, number of votes, nominations. It can even be something like: both movies involve a girl being murdered. The winner of the game can either start a new one after or say "pass" and I will do it.

After 12 hints, the original poster gets the point and also get to do another one.

Scoreboard:
Allaby: 3
FredBurroughs: 4
Kawada_Kira: 1
Stratego: 1
MinaVladimir: 1

I still don't fully get how this works and I suck at giving clues. Good luck.

HINT 1 (One Flew Over the Cuckoo's Nest): Both film's directors come from the former Eastern Bloc.
HINT 2 (Sunshine): People go craaazy!
HINT 3 (The Pianist): The story takes place in Europe (bonus clue: runtime over 2 hours).
HINT 4 (The Room): A relationship falls apart.

The film was Possession (1981)