Speaking at the event, organised by their Heads Together organisation, Kate said wants everyone to know that it's okay to ask for help.
‘All of us know someone who has been through difficult emotional times, and we know how hard it can be to see a way forward.
‘William, Harry and I feel it is our duty to do what we can, with your help, to shine a spotlight on emotional well-being and highlight the support that is out there to prevent or manage the pain at difficult times.’