(Cover) - EN Showbiz - Michelle Williams has confessed shes never happy during the making of movies.

The 30-year-old American actress has enjoyed a hugely successful year so far, receiving a best actress Oscar nomination for her portrayal of depressed wife Cindy in romantic drama Blue Valentine.

Michelle has spoken a great deal about the trauma she experienced in the making of the gritty film, although she admits her struggles were not solely linked to Blue Valentine, as she always feels unhappy making films. Michelle has won praise for her parts in films such as Prozac Nation, Brokeback Mountain, I'm Not There and Shutter Island and is attracted to deep characters who are often experiencing mental torment.

I never feel happy when Im playing a character. Theres always a level of torment and agony that I experience on a set where I need to force myself psychologically and physically to keep me going, she told the British edition of OK! magazine.

Michelle enjoyed working with her Blue Valentine co-star Ryan Gosling, who played her husband Dean. She also has a great amount of respect for director Derek Cianfrance, and admits he really tested her and Ryans acting talent.

Derek pushed us beyond our limits and wanted us to be very angry with each other as much as our characters were supposed to be. Ryan and I hated having to revisit those dark moments between our characters, she added. (C) Cover Media