He urged them not to shy away from talking about mental health particularly with the high usage of social media and the internet in their age group, which led to "a lot of false realities" being "thrown down young people's throats, expecting or thinking that everybody's life is perfect".
The closed-door session with a group of six youth mentors was held at the British ambassador's residence.
Prince urges young Singaporeans to speak out about mental health
The youth mentors who attended the session have experienced mental health issues themselves and have now recovered to support others in similar situations. Some mentors are peer support specialists with a youth mental health and outreach assessment service called the Community Health Assessment Team (CHAT).
CHAT aims to remove the stigma of seeking help and to improve young people's access to support, said the United Kingdom's Foreign and Commonwealth Office (FCO).
Prince Harry urged young Singaporeans to speak out about such matters as people tend to be averse to mental health issues.
"You have to talk about your mental health in order to be mentally fit and therefore be happy and healthy for the rest of your life," he said.
Dissolving stigma surrounding mental health by reaching out
The topic of mental health is something Prince Harry has held close to his heart and has been keenly advocating. Last year, he and The Duke and Duchess of Cambridge, launched the Heads Together campaign in Britain to end the stigma surrounding mental health.
In April, he also opened up to the British media about his own mental health issues that snowballed due to his mother Princess Diana's death when he was 12. He also spoke about seeking counselling only after 20 years since the incident and his desire to help other families after feeling the impact of losing his mother.
"When you speak to other people's families and little kids and stuff, you think: 'I don't want them to have to go through the same things' ... With a little bit of experience, you want to help as much as you can and try and empower them to have that conversation, to be brave enough for themselves to talk about it at a young age, rather than bottling it up for far too long," he said.
During Sunday's session, Prince Harry also encouraged the group to create platforms and foundations to introduce the topic of mental health with their friends. He also touched on the importance of hobbies, or healthy ways to cope ̶ such as dance or music.
"If you can just help one person not have to go through what you went through, and suffer in silence, then you've saved a life," he said. MIMS
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