Fearne Cotton's husband's family didn't know she was battling with depression

Jo said: "I only found out about it when the book came out. She never sat down with me and said, 'Jo, I'm depressed.'

"But being on anti-depressants was good for Fearne and it was a good step for her to acknowledge she wasn't feeling well.

"I didn't know that Fearne had ever felt low. To me, she's always been this lovely, bubbly, happy person - but being with Jesse has been brilliant for her and she's better now."

While Fearne may not have confided in her, Jo - who was previously married to Jesse's dad Ronnie Wood - is very "proud" of her for speaking out about her struggles.

She told Closer magazine: "I'm so proud of Fearne and I think it's very brave of her to talk about her depression as other people out there may be low and depressed.

"With Fearne speaking out in public, it makes other people feel they are not alone and helps to dispel any taboos.

"There are so many things we go through and we keep to ourselves, but it's good to be able to speak up about it and it makes you feel better."

Fearne - who has kids Rex, three, and Honey, 17 months, with Jesse - previously revealed how depression left her feeling "drained" and how being diagnosed with the condition was a huge "relief" to her.

She said: "I had a real lack of energy. I felt so drained and my lust for everything that I love wasn't there any more. I'm very optimistic by nature, I wake up in the morning and I'm very excited about my day, I'm so pumped and enthusiastic about the smaller things in life and that was dead.

"Everything was a drag and felt heavy. I felt anti-social, cut-off, alienated and they were massive warning signs. Everyone has that lightbulb moment that they need to do something differently, but for me it was feeling stuck ...

"It was definitely a relief when the doctor identified what was happening to me. It took it away from being my fault. I was prescribed anti-depressants. I decided it would get my head above the clouds for a moment. I'd never taken them before so it felt like it be worth a go."