The duke of Cambridge Prince William penned a Father's Day note in the Sunday Daily Express that touches on a message of fatherhood and mental health.

“For me it is a day not just to celebrate how fortunate I am for my young family, but to reflect on just how much I’ve learned about fatherhood and the issues facing fathers in all walks of life,” his letter reads.

The father of two continued his message around mental health and childhood stability.

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"What we have seen time and time again is that so many of the issues that adolescents and adults are dealing with can be linked to unresolved childhood challenges – addicts that were not getting treatment for a serious psychological condition that started in their teens; men who committed suicide who had been depressed since they were in primary school; homeless teenagers who could not confront significant emotional challenges."

The duke and duchess of Cambridge along with Prince Harry have been advocates for mental health this year. They were featured in a video Saturday at the Head's Together Father's Day breakfast.

“It is often said that fathers can often find it hard to talk about their own feelings so there’s no wonder they struggle to speak to their son or daughter about the topic,” he writes.

“I really believe that a child’s mental health is just as important as his or her physical health.”