Prince Harry has called on "everybody else in a position of authority" to help tackle the stigma around mental health and the lack of support services, a subject he admitted is "politically sensitive".
He was speaking to Sky News just days after he opened up about having counselling following the death of his mother Princess Diana.
Harry said he is now "in a good place" but dodged a question about whether he was happier now that he has a girlfriend.
Asked about what can be done to boost the provision of mental health services at a time when trusts fear funding is being cut, he said: "It is politically sensitive... it's not our job to make those changes.
"Our job specifically for this campaign is to remove the stigma to allow the conversation to happen."
He added: "As I've said before this is everyone's responsibility.
"This is our responsibility, yours, the media across the UK and across the world, and everybody else in a position of authority, so we need to make sure this is a team effort and that we change it now and within the next year not in 10 years' time."
Harry was at the Excel centre in London opening the Marathon expo event.
This weekend Heads Together, the joint mental health campaign launched by Prince Harry and the Duke and Duchess of Cambridge, is the main charity partner for the London marathon.
Speaking about why he decided now was the right time to talk publicly about the impact losing his mother had on him, Harry said: "I think the fact that we've been doing this campaign for a year now and the stories that we've heard, the people we've met, now was the right time.
"You know 20 years after our mother's death for us to be able to share our experiences and say you know what it doesn't matter who you are, everybody has mental health and the better you are at sort of dealing with your mental fitness the better person you end up being."
Asked about how it felt to be called brave and compared to his mother Princess Diana, he added: "I see it as being one of those people that was unfortunate enough to have those experiences, but as I said I'm just one of millions of others and every single person has dealt with it in different ways.
"All I was trying to do was say my bit and encourage others to speak openly and deal with something when it's small rather than let it snowball."
At the end of last year Prince Harry admitted publicly that he was dating the actress Meghan Markle.
He avoided answering a question about whether he was now happier because he had a woman in his life, but went on to say he is in a "good place".
He said: "Yeah I'm in a good place, we're all in a good place and we want the UK to be in a good place as well, and we can't stand the idea of people, whether it be small children, parents, veterans, white van drivers, CEOs of companies, whoever it is - we can't stand the idea that people are suffering in silence.
"The appetite is there and together as a country we can make a massive difference that will be appreciated across the globe."
Heads Together is expected to raise millions of pounds this weekend after already helping to boost the profile of the eight charity partners.