In a rare public address, the Duchess of Cambridge has sought to break the stigma surrounding children who suffer from mental health issues.

Kate Middleton, 33, gave the heartfelt video appeal on behalf of the children’s mental health charity Place2Be, of which she is patron. 

Speaking in clear, measured tones, the royal - who is mother to one-year-old Prince George - said she and husband Prince William both felt strongly about the need for greater understanding of difficulties such as self-harm and depression. 

"Both William and I have seen that many young people are struggling to cope with the impact of bullying, bereavement, domestic violence, family breakdown and more," Middleton said, in the statement to mark the UK’s first Children’s Mental Health Week (from 16 to 22 February).

"Without support, the effects of these challenges can be traumatic, leading to serious issues such as anxiety, depression, addiction, and self harm.

"A child's mental health is just as important as their physical health and deserves the same quality of support," she said. "William and I sincerely believe that early action can prevent problems in childhood from turning into larger ones later in life."

A Kensington Palace spokesman said the Duchess had seen first-hand the traumatic effect that "addiction, poverty, abuse, neglect, loss and illness of family members" can have on the emotional well-being of children.

"The Duchess of Cambridge is especially concerned with early intervention mental health support for young people, to tackle these issues at the earliest possible stage, so that children have the brightest possible futures, as they deserve," the spokesperson said. 

In the video, the Duchess said that people would not hesitate to seek help if their child had a broken arm; but to seek similar support for emotional difficulties sometimes triggered feelings of embarrassment or discomfort. 

"Together, with open conversations and greater understanding, we can ensure that attitudes towards mental health change, and children receive the support they deserve," she said. 

William and Kate are expecting their second child together this April. He or she will become fourth in line to the throne, behind older brother Prince George, who is 18 months old. 

Place2be supports children suffering from emotional difficulties in various ways, including one-to-one counselling - a method they say helped 84% of children with severe problems improve in the years 2012-2013.

Catherine Roche, chief executive, said the charity were "thrilled" to have the support of the Duchess of Cambridge for their campaign. Watch her video message, below. 

Photo: Rex Features