Imagine if you could go back in time and tell Diana not to get in that car. Or tell Carolyn Bessette-Kennedy to stay in Manhattan that Friday evening.

Imagine if you could call up Amy Winehouse that summer in 2011, tell her none of this is worth it — not the fame, not the silly boyfriend, not the album. What matters is her life.

It's a stupid fantasy, I know.

What kind of power does a random person have over an iconic celebrity? But I feel like we're living through all those moments right now with Britney Spears. And I want to sound the alarm, even though, of course, I know it's pointless.

In the early hours of March 5, Spears, 44, deleted her Instagram account.

The night before, she was arrested in California on suspicion of driving under the influence of alcohol and drugs; the car was travelling "erratically" and at high speed.

The DUI comes just a month after she sold her entire music catalogue and four months after her ex-husband and father of her two sons, Kevin Federline, released a memoir about his relationship with her — something that she has said hurt her deeply. In October last year, she appeared with bruises and bandages on her body, which she brushed off as an accident at a friend's house.

A representative for Spears released a statement on Friday, saying, "Britney is going to take the right steps and comply with the law and, hopefully, this can be the first step in a long overdue change that needs to occur in Britney's life. Hopefully, she can get the help and support she needs during this difficult time."

The rep added, "Her boys are going to be spending time with her. Her loved ones are going to come up with an overdue needed plan to set her up for success for wellbeing."

Are they? Are these the same loved ones who put her in a conservatorship for 13 years? The same ones she wrote about on her Instagram page in February, saying, "I feel incredibly lucky to even be alive with how my family treated me … and now I'm scared of them."

We know that fame can be dangerous, especially for women, and especially for those women who landed in the public eye in the early 2000s. These were the same years America's Next Top Model was being lapped up by a public hungry to punish women for being too fat, too loud, too dumb, too slutty, too much.

The casual brutality wielded by the online tabloids against teenage girls (Britney was only 16 when she released 'Baby One More Time') was justified as something they deserved for seeking the limelight.

Other women of that era have managed to survive it — Lindsay Lohan, Lady Gaga and Taylor Swift, among them. But those women always seemed to have someone in their corner. It seems as if Britney never really had anyone.

As she said in the wake of Federline's memoir, "If you really love someone, then you don't help them by humiliating them."

When a person has been consistently exploited and stripped of their autonomy for the better part of their life, the fact that they struggle is no great shock. But that may be part of the problem.

We're no longer shocked that Britney Spears seems unwell, even though what we are witnessing is the ongoing cost of a life lived under a microscope, where every cry for help was demeaned or subsumed and managed by those with a vested interest in her staying productive rather than healthy.

The hope now is that the noise of the headlines doesn't drown out the actual need for care — the kind of comprehensive help that prioritises her humanity over her brand, before she becomes one of those doomed blondes we all love to worship. Before it becomes too late.

Feature image: Getty.