'It overshadows everything': Samantha Cameron opens up about her 6-year-old son's death.

Samantha Cameron, the wife of former British Prime Minister David Cameron, has spoken about the death of their six-year-old son in 2009.

In an interview with The Times, the 45-year-old revealed that the death of Ivan – the couple’s first child – “overshadowed everything” in her life.

“Ivan dying is such a massive thing that everything else is irrelevant,” she said.

“It just overshadows everything. What goes on in the outside world becomes meaningless. Like anyone else in my situation, I just kept going. You have to deal with it, because you have no choice.”

Ivan suffered from a rare and severe form of epilepsy, Ohtahara syndrome, and cerebral palsy. He died at London's St Mary's Hospital in February 2009.

Throughout his life, Ivan needed constant care at night, with both David and Samantha often taking turns sleeping in his room. Ivan's condition meant he was unable to speak.

But despite knowing about Ivan's illness, Samantha said there was nothing the couple could have done to prepare themselves for his death shortly before his seventh birthday.

"For the whole time Ive was alive, you were always dealing with life or death situations, but it doesn’t prepare you for when you are actually faced with it," she said.

"When it happens, it is still a huge shock."

The British couple have three other children - Nancy, 13, Arthur, 11, and six-year-old Florence.

Cameron admitted she still finds it quite hard to talk about her son's death.

"It is one of the reasons I am quite private; I can’t talk about it, but I can’t not talk about it," she said.

"I still have four children and I think about him the whole time. It’s all so complex - nothing is ever black and white. There were so many emotions and that’s why grief is so hard.

"We have pictures of him all round the house; we go to visit his grave very often," Samantha said.

"Florence talks about him the whole time as though she knows him, when she never met him. It’s the biggest thing in my life."

Listen: TGM on how men grieve differently after the loss of a child.