Britain’s Prince William and popstar Lady Gaga have joined forces to promote the importance of being open about mental health issues.

Last year, Lady Gaga released an open letter detailing her fight with Post Traumatic Stress Disorder.

“For me, waking up every day and feeling sad and going on stage is something that is very hard to describe. There’s a lot of shame attached to mental illness. You feel like something is wrong with you,” she says in a video call with the prince.

Their call features in a charity film showing the pair chatting from their homes in London and Los Angeles. In it, they highlight the need to normalise discourse about mental health.

“It’s OK to have this conversation, it’s really important to have this conversation and you won’t be judged. It’s so important to break open that fear and that taboo, which is only going to lead to more problems down the line,” said Prince William.

Together with his brother Harry and his wife Kate, William is spearheading the “Heads Together” campaign.

Prince Harry recently broke with royal tradition and spoke out publically about his own issues following the death of his mother, almost 20 years ago.