Former SA Lib talks about bipolar battle

Mental illness is not an excuse for breaking the law, Former South Australian Liberal Senator Mary Jo Fisher says.

Ms Fisher has spoken about her own battle with bipolar disorder - which saw her resign from politics after being acquitted of stealing groceries from an Adelaide supermarket and found guilt of assaulting a security guard in 2011 - for Mental Health Week.

"For me, with bipolar, I can't beat it. I'm going to have it for the rest of my life. But I can learn to manage it," she told ABC radio on Tuesday.

"Mental illness is not an excuse. Because you're depressed, you can't go out and egg someone's car."