Helena Bonham Carter is convinced that she has the “potential” to become insane.

Several of her ancestors, including her mother, suffered with mental illness, according to the Alice In Wonderland actor.

Helena, who has been with Tim Burton for a long time, 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.

Photograph: AP

“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 counseling for her issues, but she’s not sure if talking to someone helped.

She said, “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.”