Prince William Opens Up About Pain Of Losing His Mother

Prince William has spoken about the pain of losing his mother, Princess Diana, in a new documentary.

The Duke of Cambridge, who was just 15 when his mother died in a car crash,  said dealing with the loss had a tremendous impact on the state of his mental health. 

"I've thought about this a lot, and I'm trying to understand why I feel like I do..." Prince William said in the new BBC documentary, 'A Royal Team Talk: Tackling Mental Health'.

The late Diana, Princess of Wales, holds Prince William in the 1980s. PHOTO: AAP

"... But I think when you are bereaved at a very young age -- any time really, but particularly at a young age, I can resonate closely to that -- you feel pain like no other pain."

READ MORE: Prince Williams Tears Up Revealing 'Very Difficult' Moment Related To His Children 

William added the tragic experience of losing his mother meant he formed strong connections with families he worked with during his time as an air ambulance pilot.

William said the emotional nature of the job, helping families who are having "the worst news the could ever possibly have" meant he recognised he had to protect his own mental health.

"That raw emotion... I could feel it brewing up inside me and I could feel it was going to take its toll and be a real problem," he said.

"I had to speak about it."

READ MORE: Prince Harry Opens Up About 'Missing' Mum Princess Diana After Birth Of Baby Archie

The now father-of-three spoke about the British tendency towards the "stiff upper lip" in difficult times, but encouraged people to "relax a little bit and be able to talk about our emotions because we're not robots".

William has been a fierce advocate for opening up conversations around mental health and tackling the stigma that often surrounds it with his charity, Heads Together.

If you need help in a crisis, call Lifeline on 13 11 14. For further information about depression contact beyondBlue on 1300 22 4636 or talk to your GP, local health professional or someone you trust.

Main Photo: Network 10.