She was once reported as saying "you can never be too rich, too thin or have too much cashmere" but now it seems that Tara Palmer-Tomkinson, the London It girl and habitual presence on the fashionable party circuit has had too much of just about everything else.

This pretty social butterfly has just checked into the exclusive Meadows Clinic in the Arizona desert, apparently suffering under the weight of a punishing party schedule that takes her from the ski slopes of Klosters to castles in Ireland, all of which makes for an entertaining read in her social diary for The Sunday Times.

Her new agent, Toby Pocock, explains that Tara is simply wiped out by her fast-living, fun-loving lifestyle and is seeking a more serious direction in life. There is nothing "sinister" about the divine "Ms PT" 's flight to the desert, but speculation about her health and her bizarre behaviour on the Frank Skinner Show last week prompted one TV commentator to describe her performance as something from "another planet".

Ms Palmer-Tomkinson, younger daughter of the landowner Charles Palmer-Tomkinson and his wife Patti, was destined to be a minor socialite and fashion assistant until one day in 1994 when she planted an innocent kiss on the cheek of family friend Prince Charles. The world's paparazzi were there on the ski slopes to capture the moment and after that Ms P-T's star was in the ascendant.

With the helping hand of M&M Management in London, she was soon being photographed on the arm of the fashionable restaurateur Mogens Tholstrup, and multimillionaire boyfriend Robert Hanson. In the past five years she has been everywhere the It girl should be.

But this 27-year-old is no pushover. She might come across as an air-head but she was sassy enough to send up the It girl image in an otherwise forgettable advert for Kentucky Fried Chicken last year and it's possible she won a few fans in the process. She even wrote an article for The Spectator defending her lifestyle while pointing out that she has three A-Levels and a weakness for Jane Austen. Even her detractors will admit she is a consummate professional in her attitude to her work. But how difficult can it be to wear pretty dresses and party all year?

So, for now Tara is taking it easy in Arizona, attempting to deal with an inner torment, or as others suggest some kind of addiction, far from the glitzy round of lunch at Le Caprice or shopping with Noel Gallagher's wife, Meg Matthews.