Doctor Alex George has admitted that he had no idea his younger brother Llyr was battling mental health issues when he decided to take his own life last year.
The 19-year-old was just weeks away from starting medical school when he committed suicide in July, leaving his family reeling.
"I was at a restaurant when I found out," Alex wrote in The Sun. "My dad called me and immediately I could tell something was wrong, something bad had happened. I asked him who had passed away.
"What came next was the most indescribable physical pain I've ever felt. He told me my youngest brother Llyr had died, and he'd taken his own life at the age of 19. In that moment my world fell apart, it came down around me. It shattered."
He continued: "It doesn't follow the trajectory of conditions like pneumonia or broken bones. Each and every person who experiences poor mental health is unique.
"Not once did Llyr tell me how he was feeling. I'm a doctor, we were very close, he knew I was a mental health advocate and hugely passionate about it.
"We spoke and messaged constantly and still he kept how he was feeling to himself.
"That tells you everything about the sense of stigma and shame we still have attached to mental health issues in this country."
Alex has now started a campaign to introduce better mental health awareness and support in schools and in recent weeks has begun discussions with the government over the project.