WHEN Denise Welch talks about her 18-year battle with clinical depression, her words echo with the authority of a woman who truly knows what rock-bottom is. And she doesn't pull any punches as she describes the debilitating effects of an illness which affects countless thousands in the UK, but still carries a stigma.

"I wouldn't be here today were it not for the incredible support and understanding of my family and friends. They literally saved my life. Without them I would be dead," she says, matter-of-factly.

Cheshire-based Denise, married to actor Tim Healy and a mother of two, is undergoing a new hormone-based treatment which, it is hoped, may finally help silence the unpredictable demons which have blighted her life. But there are no guarantees. No real cures. And her road to a controlled depression-free future is littered with the ghosts of previous false dawns.

She says: "I won't be able to say for six months or so whether this latest treatment I am having is working or not. So far so good, but I have been here before with other treatments and then the depression comes back with a vengeance when I think it is finally under control.

"So I'm not going to say anything until I have reached the six-month period, then we may be in a better position to say if it is working or not."

Denise, known from her appearances in BBC TV series Waterloo Road, as former Coronation Street landlady Natalie Barnes and as a panelist on talk show Loose Women, is convinced her personal depression came on when she was pregnant with her now 18-year-old son Matthew.

"I believe it was triggered by something hormonal," she says. "But whatever the cause it keeps coming back and nothing has really worked to control it over a sustained period of time."

The latest blackness descended when Denise was on a family holiday in Portugal just a few weeks ago. It was completely unexpected.

"I was sitting there in Portugal sipping from a cup of tea when I could just feel it start to happen," she says. "The blackness came back and was very intense. I'm 48 now and the depression has been getting more intense over the past two years."

Despite crippling bouts of depression Denise has managed to cope with illness, her role as mum, wife and actress - apart from one occasion memorable for all the wrong reasons.

Stockport

"Nearly three years ago when I was in panto in Stockport I had to pull out because I was on the verge of a nervous breakdown. It was the first time it seriously affected my work like that.

"But I had no choice. I just couldn't function. What was awful was that one of the other actresses had fractured her wrist and in one of the newspaper articles it praised her for returning to work despite her injury and almost made a mockery of my situation.

"That's the problem with depression. Even though it is an horrendous thing, because it is not physical it is treated with contempt by many people. There is a lot of ignorance when it comes to clinical depression. I was once even told to get a hold of myself and snap out of it by a GP of all people."

It is with the profile and public image of depression in mind that Denise has agreed to become an advocate for Manchester-based support group Mood Swings, which is run by the father of her former Coronation Street pal Jennie McAlpine.

"If by talking about my clinical depression I can help focus attention on the problem and foster a bit more understanding of what sufferers are going through, then I feel like I should be doing it," she says.

"I am in a fortunate position where people will listen to what I say because I am an actress and appear on TV. So I want to use that position to do whatever I can to help."

She's also quick to point out how the current celebrity obsession with rehabilitation clinics is doing the image of depression and its sufferers no good. She says: "All these celebs are checking into places like The Priory for no reason other than they've had a wild weekend and drunk a bit too much. It's become a bit of a joke."

Denise is currently working on the third series of hit TV series Waterloo Road, all shot in Manchester. She says that since she started the hormonal-based treatment under Dr John Studd at London's Lister Hospital, all is well.

She says: "I am incredibly lucky - I have a loving and amazingly supportive family, a nice home and a great job. Most days are great, if unusually busy, at the moment."