KEY POINTS:
After two 24-hour stints in separate rehab facilities, Spears has confirmed her lead in 2007's celebrity train wreck race.
But Brit isn't the only celeb to head off the rails this year. A quick look back over the past two months reveals a number of high-profile individuals are battling various demons behind rehab doors.
Stuart Anderson, programme director of Auckland's Higher Ground Drug Rehabilitation Trust, said the decision to enter rehab is a courageous one, however, people need to be prepared to deal with their problems when they arrive.
"If someone checks out after a day, it shows they're doing what they think needs to be done but they're not ready to undertake the process," said Mr Anderson.
Residential rehabilitation facilities around the world have long waiting lists, said Mr Anderson, and if someone is not prepared to work on their problems, it is likely they would be asked to leave.
"It is a very special environment to be in. It's probably better to leave if you're not prepared to work on your problems," he said.
While it seems Spears' rehabilitation is yet to commence in full, other stars have stepped up and completed their respective programmes.
Take a look at our celebrity rehab tally and see why 2007 is set to be the year of rehab:
DRUGS & ALCOHOL
Lindsay Lohan
After months of hard-partying and eyebrow raising antics, Lohan's mother announced last December that the actress had been attending Alcoholics Anonymous meetings. A month later, Lohan checked herself into Los Angeles' Wonderland facility after an all-night drinking binge following the Golden Globes, where she was reportedly found passed out in a hotel hallway. Lohan has since left the facility and, though she has been seen out at various nightclubs, reports say she is staying sober.
Keith Urban
After battling his demons with drugs and alcohol in 1998, Urban entered rehab for a second time in October last year. Initially planning on a 30-day stay, Urban remained at the Betty Ford Clinic in Palm Springs for 90 days, finally leaving the facility in January this year.
Robbie Williams
Ten years after Williams last entered rehab, the former boy bander announced his return to rehab on his 33rd birthday. Williams entered a US-based facility last week, for an addiction to prescription medicine - believed to be anti-depressants. Williams admitted addictions to cocaine and alcohol during the mid 90s, a period he later described as "a black hole".
Tara Conner - Miss USA
The 21-year-old beauty queen made headlines last December when Donald Trump allowed Conner to keep her crown, on the condition that she enter rehab. Conner spent Christmas and New Year's at the Caron Foundation in Pennsylvania, before being released in January. Since leaving the facility, Conner has admitted she is an alcoholic and had tried cocaine.
BEHAVIOURAL ISSUES
Isaiah Washington
Grey's Anatomy star Washington hit headlines after the Golden Globe Awards last month, when he announced to a room full of reporters that "I did not call T.R [Knight] a faggot." Accused of homophobia, Washington checked into a rehab facility on January 24 and issued a statement, which read:
"With the support of my family and friends, I have begun counselling. I regard this as a necessary step toward understanding why I did what I did and making sure it never happens again. I appreciate the fact that I have been given this opportunity and I remain committed to transforming my negative actions into positive results, personally and professionally."
UNKNOWN DEPENDENCY
Britney Spears
Reports say Spears checked into Eric Clapton's rehab facility Crossroads, in Antigua, last Friday, only to leave 24 hours later. After this weekend's notorious head shaving episode, Spears checked into the Promises rehabilitation centre in Malibu on Tuesday, before checking out yesterday.