Helena Bonham Carter - Helena Bonham Carter's 'Insanity' Fear

Helena Bonham Carter believes she has the "potential" to go insane.

The 'Alice in Wonderland' actress - whose mother Elena suffered a severe breakdown 38 years ago - believes mental illness is hereditary and accepts the fact she may suffer herself in the future.

Helena - who is in a long-term relationship with Tim Burton - said: "There's a good streak in our family of, I'd say, healthy insanity. My mother, and I know, my grandmother and great-grandmother. I think it's very much genetic.

"I haven't suffered yet, but I know there's potential there. I've been depressed and don't like it. I was definitely depressed when I was 18, wondering who I was.

"I was under a lot of scrutiny but I hadn't worked out for myself whether I wanted to act. I felt very isolated because I was out of my peer group."

Helena, 43, sought therapy for her problems, but is unsure whether speaking to someone helped.

The actress - who landed her first acting role at 16 - added to The Times newspaper: "I had therapy. I'm not sure if the therapy helped. It just passed. It was fine. You find a way through it, but it is hard, still, to talk about it."