Catherine Zeta-Jones: Darling bud with a steely core

Clad in shimmering Versace, Catherine Zeta-Jones looked a picture of Hollywood glamour when she swept to the stage of the Radio City Music Hall in New York last June to accept a Tony, American theatre's equivalent of an Oscar, for her role in the Broadway hit A Little Night Music.

But then she opened her mouth. After a long and rambling speech, in which she gushed endlessly about the cast and crew, she turned to husband Michael Douglas in the stalls. "See that man there?" she squawked. "He's a movie star! And I get to sleep with him every night!"

The comments, blurted over the rumblings of a pit orchestra which had begun playing the Welsh actress off stage, were cited as evidence that removing Swansea from the girl is significantly harder than removing the girl from Swansea. Later, she issued an apology to TV viewers who might have been offended. "I was so caught up in the moment I don't think I knew what I was saying," it went. "I had no control over what was coming out of my mouth ... I can't believe I said something as crass as that."

Fast forward 10 turbulent months, and the events of that night take on a different hue. Douglas now has throat cancer. Zeta-Jones, for her part, revealed this week that she is suffering from bipolar II disorder, a mental illness in which sufferers can experience severe mood swings. To armchair psychiatrists, who are rarely in short supply when a member of the A-list hits choppy water, her performance on last year's Tony Award podium is evidence that her problems may have been brewing for some time.

Yet beyond prurient speculation, the 41-year-old star's decision to go public with her troubles has met with goodwill. The frankness with which her spokesman discussed the condition gladdens organisations that deal with mental health issues. They have released statements celebrating her "bravery", hoping the rare spectacle of a public figure confronting psychological demons will lift some of the enduring taboo surrounding mental illness.

That said, the circumstances under which Zeta-Jones confirmed that she recently spent five days at the Silver Hill hospital in Connecticut involved a hefty dollop of journalistic intrigue. This week's whirlwind began late on Tuesday, when her publicist, CeCe Yorke, got wind of the fact that the National Enquirer, America's most invasive supermarket tabloid, intended to splash with news of the so-called "mental breakdown".

Ms Yorke, an expert in damage limitation, is no fan of the Enquirer, which recently covered Douglas's ongoing treatment for his cancer by claiming that he had "just months to live". She therefore decided to "kill" their exclusive, emailing an announcement to rival news outlets. "After dealing with the stress of the past year, Catherine made the decision to check in to a mental health facility for a brief stay to treat her bipolar II disorder," it read. "She's now feeling great and looking forward to starting work this week on her two upcoming films."

With that, Zeta-Jones's illness was made public, and her rosy reputation adroitly protected. So too was her standing as a fully paid-up member of Hollywood royalty. Not only does she have an Oscar under her belt, untold riches in the bank, and two young children who are scions of a dynasty which began with her father-in-law Kirk Douglas, she has also tightened her grip on of one of the most important properties in show-business: the general public's affection.

"What can you say about Catherine, except that she's a gal?" says Gayl Murphy, an entertainment commentator who has often interviewed her. "She's beautiful, tough, likeable and completely charming when you meet her in person. And most of all, she can really act. I mean, what wouldn't someone like Jennifer Aniston give to have her life? And now of course everyone will be rooting for her."

They may not need to. Throughout her life, Zeta-Jones has enjoyed great fortune. In childhood, her working-class parents, Pat and David, won £100,000 during a night at the bingo, allowing them to enrol their daughter in dance and ballet classes. Later, they sent her off to acting school in London where, at the age of 15, she was plucked from obscurity to headline a West End production of 42nd Street.

The wider British public would first catch wind of her charms in 1991, when she landed the role of Mariette in a hugely successful TV adaptation of the H E Bates novel The Darling Buds of May. Aged 22, and overflowing with comely charm, she was an instant media darling. In the ensuing years, she cultivated a string of celebrity boyfriends. They included the Blue Peter presenter John Leslie, crooners David Essex and Mick Hucknall, actor Paul McGann, and Soldier Soldier star Angus Macfadyen, to whom she was briefly engaged. Asked to describe her lifestyle, in a 1995 interview with the Daily Mirror, she declared: "I drink, I swear, I like sex."

Shortly afterwards, her engagement to Macfadyen crumbled. With her TV stock falling, and her 30th birthday approaching, a lesser actress could have flatlined. But with typical pluck, Zeta-Jones decided to roll the dice once more, figuring that Hollywood offered a chance at reinvention. She soon won a role in the television mini-series Titanic. It impressed Steven Spielberg, who then recommended her for the female lead in a new Antonio Banderas project called The Mask of Zorro. Released in 1998, it became a breakout hit.

Not long afterwards, she was introduced to Michael Douglas, who was then 25 years her senior. He had separated from his wife of 23 years, Diandra Luker, and was instantly smitten, using the immortal chat-up line: "I'd like to father your children." A few years later, he got his wish. They now have a son and a daughter, and large homes in Mallorca, New York, Los Angeles, Canada, Wales and Bermuda, where they spend most of their time.

Artistic credibility arrived in 2000, when Zeta-Jones was nominated for a Golden Globe for the critically acclaimed Traffic. In 2003, when heavily pregnant, she carried off the Best Supporting Actor gong at the Oscars for Chicago. Since then, she has picked and chosen film roles carefully, opting to spend time with her family. As a result, she has perhaps avoided the overexposure which afflicts so many leading ladies.

As befits the topsy-turvy nature of her life, Zeta-Jones is always anxious to emphasise that she's in touch with her roots. In interviews, she is constantly self-effacing and energetic, and makes a habit of name-checking the Mumbles, where her family still lives. (Her brother Lyndon works as her manager.) In fluffier moments, she'll talk about her fondness for the game of golf, and all things Welsh.

Away from the camera, she sometimes boasts a steely core. That much emerged in the years after her wedding, when she and Douglas pursued an action against Hello! magazine for publishing unauthorised photographs of the event, which had been sold to OK!. It also became clear a few years back, when she succeeded in persuading Virgin Books to cancel a planned biography by the noted scandal-monger Cliff Goodwin.

Details of how the book was stopped remain unclear. But Goodwin's agent, Jane Judd, gives the impression that he remains bruised by the affair. "He just won't talk about her," she said this week. "He wrote an entire book and it got stopped by lawyers. So he's understandably concerned that anything he says could land him in trouble." Whatever Zeta-Jones has that is capable of scaring a grown man so comprehensively will – with a bit of luck – stand her in good stead in the weeks and months to come.

A life in brief

Born: 25 September 1969, Swansea, Wales.

Family: Daughter of an Irish seamstress, Patricia Fair, and a Welsh sweet factory owner, David James Jones. Named after grandmothers Catherine Fair and Zeta Jones. Married actor Michael Douglas in 2000. They have a son, Dylan, and a daughter, Carys.

Education: Left Dunburton House School, Swansea, without O-levels. Took musical theatre course at the Arts Educational Schools in London.

Career: Professional stage debut aged 12 as lead in Annie at Swansea Grand Theatre. First screen appearance in 1990 in Les 1001 Nuits. Earned fame a year later as Mariette in an ITV drama, The Darling Buds of May. Since her Hollywood break in The Mask of Zorro, she has appeared in more than 20 films. Won Best Supporting Actress Oscar for Chicago in 2002 and a Tony Award for A Little Night Music in 2010. Appointed CBE in 2010.

She says: "People assume I have confidence and Hollywood glamour, when actually, sometimes I'm just a goofball."

They say: "When I discovered she loved golf, I realised my fantasies had come true." Michael Douglas