The Duchess of Cambridge today launched a keen appeal to support teachers in the battle to improve children's mental well-being.
Speaking at the Royal Foundation's mental health education conference, Kate said parents and parents should work with teachers to support young people and guide them on the right path.
"None of us can make a difference alone," he said.
The royal mother of three said: "I feel so passionately about working together and being here today has confirmed to me what is already being done, so thanks to all of you who are prioritizing the importance of mental health and importance of the development of childhood as a whole. "
Kate, who spent eight years working with charities, met some of our leading experts in mental health, addiction, family breakdown, homelessness and education, says she believes that many social problems can be traced back to childhood .
The Duchess said: "They (the experts) have taught me over and over again that the root cause of so many of today's social problems can be traced back to the very first years of a person's life and often through generations.
"Scientific and other evidence is clear: the early years of a child's life are more crucial to the development and to the health and future happiness of any other single moment in our lives.
"It is also clear that the positive development of our children is directly linked to those who take care of them, teachers, carers and parents", he continued.
"It is therefore essential to support teachers with their well-being so that they can find the best level of care for all the children in their schools and communities where they work, but none of us can make a difference on their own," he said.
Previously the Duke of Cambridge was named patron of charity, who first visited as a boy with Princess Diana.
William, 36, became the nominee of The Passage, an organization based in St Vincent's Center in Westminster that has helped over 130,000 people in nearly 40 years.
He was 11 years old when Diana brought him and his younger brother Harry to charity in December 1993. Kensington Palace today published a picture of The Passage's visitor book, which showed where William had signed his name, along with that of his mother, in that visit.
William, who was also the patron of the Centrepoint homelessness charity center, said his visits to the children's center left "a deep and lasting impression".
He has made numerous public and private trips to the center since then, even with the Duchess of Cambridge before Christmas, when he spoke about the effect of drugs on the homeless.
He joined charity volunteers today to help prepare and serve lunch in his first official engagement as a patron.
Cardinal Vincent Nichols, head of the Catholic Church in England and Wales and patron of The Passage, said: "I know that the Duke is deeply committed to working with the neediest, like the thousands of people who helped The Passage from the streets" The managing director of charity, Mick Clarke, said that during William's visits "it was very clear that he has a deep concern for the people affected by the homeless".
Kate, William and the Duke and Duchess of Sussex coordinate the Foundation for mental health in the education of the Royal Foundation, which also leads the Heads Together initiative.