Patients looked on in horror when a man burst into the psychiatric hospital brandishing a carving fork which he forcefully stabbed into the reception desk.

But for charge nurse Jo Brand, this was just another day.

"He then pulled the knife out and was waving it about demanding to see someone. If you got frightened and panicky that would escalate the situation. You had to speak in a calm voice and not bark out orders like a headmistress," Brand recalls.

In her 10-year career as a psychiatric nurse in south London before she went into comedy, the comedian was threatened with guns, knives and other sharp implements and was attacked on numerous occasions.

Scary times, but meeting the 52-year-old today in Dulwich Picture Gallery near her home in leafy south east London, she is a sea of calm, dressed in black, holes in her hoody, a slightly comic bandana trying to tame her choppy hair.

We're here to discuss the first volume of her autobiography, Look Back In Hunger, much of which focuses on her career as a psychiatric nurse, only reaching her first steps into comedy in the last few chapters. Volume two is due next year.

"I prefer the coal face of nursing," the mother-of-two reflects. "I miss it a lot, particularly working with a group of people I got on well with, because stand-up's a fairly solitary existence."

She loved her job as charge nurse at the emergency clinic of the Maudsley psychiatric hospital, south London.

"I liked the excitement. It was occasionally dangerous and depressing and heart-rending, but you did at least feel you were intervening at a crisis point and doing something.

"It taught me how to interpret situations and to withstand a lot more abuse than most women can."

Brand broke into comedy in 1986 and her book ends as she is just starting to make a name for herself on the circuit.

"I'd wanted to do comedy for years because I was just so caught up in the romance of being a stand-up comic, just the ability to make a whole group of people laugh, just by what you say. It was like a huge challenge and I came from a family that likes a good laugh."

Her time as a psychiatric nurse put her in good stead for the knocks she would take as a comedian in later years.

"At the time I couldn't really connect comedy and nursing but, looking back now, I realise that the amount of verbal abuse I got as a nurse, and the way that I had learned to let it wash over me, set me up as a bit of a tough old bird able to deal with hecklers."

That was all a long time ago now. Today she is a regular on panel shows like QI, with Stephen Fry and her pal Alan Davies, although she will no longer appear on the BBC2 show Mock The Week, hosted by Dara O Briain.

"It's too fast, too stressful and too demanding for me," she says simply.

Meanwhile, another series of the black comedy Getting On, in which she stars as a common sense nurse in an NHS ward full of quirky, elderly women, has been commissioned and filming should start after Christmas.

Brand admits that when she was starting out, some of her material was filthy, to create the shock element so many female comedians use to get themselves noticed.

"I wasn't aggressive until someone started on me, but then I thought it was open season and would give it to them big-time. To some extent a lot of that was a building-up inside me of all the abuse I had over the years in psychiatry and not being able to answer back.

"My favourite tasteless thing was to come on with a blood capsule in my mouth, wear a big white T-shirt, cough up what looked like blood and say, 'I must give up smoking'. I thought that was a brilliant opener. Half would laugh hysterically and the other half would look a bit queasy.

"A lot of my material was about my weight, my moustache, deliberately so because I wanted to get it out of the way."

Over the years she's been taunted about her size and her sexuality (many thought the happily married Brand was a lesbian) but nothing fazes her.

Born in south London, Brand grew up in Kent and was a bright child who passed her 11-plus and attended Tunbridge Wells Girls' Grammar School.

She loved the school and thrived in it, but neither of her parents could have anticipated the dramatic effect it would have on their daughter when her father, a structural engineer, moved the family to Hastings with his job. Brand immediately hated it.

She rebelled, started hanging out with the wrong crowd, had a series of dodgy boyfriends and dabbled in drugs.

"I had a go at smoking heroin, but it wasn't my cup of tea," she reflects. "My crutch was food. I just ate too much of the wrong stuff."

She spent much of her teenage life in a haze of alcohol and now reflects that her appalling behaviour was designed purely to get back at her parents.

"I was furious with my parents because I thought that if they truly knew what a momentous fracture in my life was going on, being moved away from close friends and school where I was relaxed and happy, to something unknown, they'd have known it was a big mistake."

At one point, her father threw her out of the house and she ended up severing contact with her parents for several years, until, returning home extremely drunk from a party, she left a candle burning in the bedroom and her flat burned down. After that, she moved back home.

She has few regrets, however, about her rebellion.

"I wouldn't be doing what I'm doing now if I hadn't done all that, because it changed me. It made me less compliant, less contented with my lot and less wanting to follow a traditional path."

Comedy has changed in the 20 years she's been on the circuit, she reflects.

Self-deprecating jokes about being fat, periods and eating cake are part of her repertoire, but there are certain subjects she feels are no laughing matter.

"I'd be very careful not to be racist or take the mickey out of mentally ill people or people with disability."

And she doesn't approve of some of the material explored by her fellow comedians.

"Poor old Jimmy Carr does some very unpalatable material. I think he's a nice bloke, I just don't like some of his jokes. I think they're cruel, racist and misogynistic.

"He does a lot of stuff about fat women. There was a joke he did about gypsy women smelling and people were up in arms about it.

"You do notice with the most recent generation of young, male comics, that they do what I would consider to be slightly misogynistic stuff, which they may consider edgy."

Brand hasn't been on a stand-up tour for a year as she's juggled other projects with family life (her husband, Bernie, is a psychiatric nurse and they have two daughters, Maisie, eight and six-year-old Eliza).

"There are pros and cons to being an older mum," she says. "Very young women who have kids are strait-jacketed to some extent in that they have to cut out their social life and then regret that.

"Older mothers have done what they wanted to do and have become established, but they're knackered!"