Ruby Wax begins with an apology. She is three hours late for the interview because she's been napping. "I did 11 calls and then I fell asleep, so I'm sorry," she says. "I got so tired of hearing my own voice."
She has been busy rehearsing for her show, which has just opened for a five-week run in Covent Garden's Duchess Theatre following a successful stint at the Edinburgh Festival.
Still, the comedienne is undismayed by the good reviews: "I'm so ready to be panned," she says. "There are people out to get you in this country. Twenty years ago I did some television work, clearly acted, and then for the rest of your life they like to peg you. You're either a Jew, or a funny person or a maniac, or whatever."
There are two things to note about Wax's two-woman show, a 'mental health comedy' called Losing It.
Firstly, Wax believes it is the best thing she has ever written. Secondly, it is definitely not about depression - her experience of the illness, or that of her co-star Judith Owen.
It's about "money, envy, loves, how nobody knows how to be an adult," she says. It's not her story - it's everyone's story.
"I didn't write it [about my own depression]. I hate the Vagina Monologues, I'm not waving a flag. I don't stand up as a feminist or, you know, as a Jew, I don't even feel like a female, or whatever age I am, I don't know.
"I may identify with it but everybody in there is nodding their head. I'm not going 'and then in 2003 I decided I'd go to...'"
For the record, the reason Wax hates the Vagina Monologues is because she once saw one of her daughters in an amateur performance of the play ("I never got over that one").
Her current play is scripted, although Wax and Owen manage to make it seem entirely fresh. In person Wax is less coherent, often trailing off in mid-sentence or changing the subject altogether. She "ums" and "ahs" her way through an anecdote about a hostile audience member:
"Once in the Chocolate Factory somebody said 'you guys are making this up' and I think a group of gay women pretty much, um, killed him after the show... when he left, I don't know what happened when he left. Pretty angry crowd."
Wax also contradicts herself. She also admits she can get it "completely wrong".
But on stage with Owen she is fluid and funny (her advice on marriage: "If a man earns £250,000 or more per year you must clean the house, look after the children and sleep with him whenever he wants. And you're not allowed to age. If he earns less than £10,000 a year, let the whole place rot").
After they perform there is a Q&A session where members of the audience line up to tell her how brilliant she is, while others heckle and shout questions or make abrupt statements about psychiatric drugs and depression. It gets moving when a blonde woman bursts into tears as she talks about her decade long battle with depression and how good it is to hear someone discussing it publicly.
There is emotion in the performances too. There's also a worrying point when Wax dolls out misinformation to the audience (she had to seek help from the Priory, apparently, because there was a dearth of nationalised mental health services in London).
She says she did not mean to suggest London had a lack of services for the mentally ill -- apparently what London lacks is a space for them to get together and talk ("like alcoholics have").
"We are in the theatre [creating that space] so they can at least, you know, don't feel that they have to hide it or constantly make excuses or pretend they're OK... That's what's lacking and that's why the Priory was sort of one option."
And Wax is doing her bit to tackle the stigma of mental health. Every Tuesday afternoon, she and Owen, along with friends, will hold a meeting in the theatre where those who need psychiatric help, or carers of mentally ill people, can get expert advice.
"Once you say the words, once I said to one of my friends 'I'm actually really sick', and you can actually say it. They sometimes step in and say 'OK, I'll help you' and so I think by people being able to say 'I'm not right', it's such a burden and this is such a relief. I'm not really offering my advice."
Wax says she was the breadwinner for her husband and three children when she was ill - she could not just stop working.
"It's all difficult," she says. "Do you feel more pity for the rich guy who gets a brain tumour than the poor guy? I just don't know... It's not a contest for who has it worse."
One in four people globally deal with mental health issues (hence the play's tagline: 'bring three friends'). It's "there but for the grace of god go I," she says.
Wax admits in the show her trigger, the thing that pulled her down into the cycle of negative thoughts, was envy. But it's not just her problem.
"How come people laugh when I say I tear out the pages of Hello Magazine? People are laughing in recognition."
She continues: "The most beautiful are the most paranoid... Usually the people that have a little bit want even more. The ones that are blessed are the guys who sit on a rock and fish all day. That's kind of the conclusion."
And Wax is paranoid too. "I don't think I'm good. That's part of the curse. I'm waiting for someone to really give it to me for doing this. I feel like somebody's going to think this was a real act of showing off. I find show business, as my daughter does, slightly embarrassing."
Parts of show business, Wax believes, are desperate. Like stand-up comedy: "I'm suspicious of that desperate quality. So the reason I have Judith, in a sense, I'm doing this for her. Seriously."
She bounces off her co-star, whom she's known for five years. For her, their partnership is what stops it from feeling "desperate".
So what's next? After the run in Covent Garden, Wax will continue performing the show in mental health hospitals ("my tribe") and hopes to expand it internationally.
Her interest in the brain and metal illness has led her to study an MSc in neuroscience at Oxford University. And with her studies, Wax finally has something to bore people about in dinner parties, after spending years hearing about "what Bismarck ate for lunch". "I'm only interested in that. I feel that before you get into politics or anything else you really have to know... why you're so fanatical about certain things."
Then she plans to write a book about "the manual" from the play - the one thing everyone needs to comprehend the twists and turns of life.
"This is the internal journey that Bill Bryson hasn't written yet," she says. "I'm going to try and incorporate my masters and twist it to make it really funny."