Up until recently the High-Rise actress felt like there was so much noise in her mind that she couldn't make decisions or take control over her life. To combat this she booked onto a week-long therapy course that focuses on Freudian analysis, which traces behaviour patterns back to the person's parents.

''(It was) f**king amazing," she tells PORTER magazine. "It's terrifying but extraordinary... It's 10 years of therapy in a week. I got back a week ago. It takes a while to settle.

"There's an immense amount of space in my head and there is no f**king noise in it for the first time. All that noise has just gone... I just got to a point where I just felt… I didn't understand why I was, I couldn't dig myself out, I couldn't make decisions, I felt pretty assaulted by life and not in control…"

Sienna had previously revealed she went to see a therapist over her on-off relationship with former fiance Jude Law, who she finally split from in 2011. She admits to the magazine that although she doesn't see him that much, "I care about him enormously."

Sienna has a three-year-old daughter Marlowe with actor Tom Sturridge, who she reportedly split from in 2015 after four years. Although she is currently single, the actress would love to give Marlowe a sibling.

"I would love more, I'm suddenly feeling very broody for more babies, and my daughter's desperate to have a sibling," she confessed.

When asked what she looks for in her ideal man, the 34-year-old says she has only ever been attracted to intelligence and those who look good but don't have the brains won't last long with her.

"I don't care about that (looks), but you know, within limits," she explains. "Someone staggeringly beautiful and thick is totally ugly to me... It sounds silly but I like bookish academics who are slightly odd, and borderline, you know, on the spectrum."