Jane Fonda blamed herself for her mother's mental health issues

Speaking on PeopleTV's 'The Jess Cagle Interview', she said: "If you have a parent who is not capable of showing up, not capable of reflecting you back through eyes of love, it has a big impact on your sense of self.

"As a child, you always think it was your fault...because the child can't blame the adult, because they depend on the adult for survival. It takes a long time to get over the guilt."

The 80-year-old actress - whose father originally told Jane and her brother their mother had died from a heart attack - admitted she never really knew her mom when she was alive.

She said: "When I wrote my memoir (2005's 'My Life So Far'), I dedicated it to my mother because I knew that if I did...I would be forced to really try to figure her out.

"I never knew her because she suffered from bipolarity."

The 'Book Club' star was able to access her mother's medical records, and also explored both her and her father, Henry Fonda's, backgrounds to get a better understanding of them and to put her own mind at ease.

She said: "When you go through that kind of research...if you can come to answers, which I was able to do, you end up being able to say, 'It had nothing to do with me.'

"It wasn't that I wasn't lovable. They had issues. And the minute you know that, you can feel tremendous empathy for them. And you can forgive."