21/04/2017 10:11 BST | Updated 21/04/2017 10:11 BST

Why I'm Running The London Marathon

Jeff Spicer via Getty Images

"My son has OCD" - it was the first time I'd talked about it outside family and close friends and this was certainly not how I'd planned it. A TV camera to my right, reporters to my left, and in front of me Prince William, listening intently to my confession. Even now, three months on, I still find those words difficult to utter, despite the fact that my 14-year-old son, has been severely affected for over a year.

Parental Stigma

Why is it so hard to talk about? Like thousands of other parents, I am acutely aware of the stigma and ignorance that surrounds mental health. It is a taboo that all too many parents face alone, worried they'll be judged or their child will be labelled. A wall of silence greets them at the school gates.

My son, is like any other teenager, apart from the fact that he has OCD. Three letters which have made a big difference to him. I know a lot about it now, but 12 months ago I had very little understanding of what obsessive compulsive disorder was.

I used to think people with OCD washed their hands excessively, kept things in order, or spent hours tidying their homes. That's the stereotype, but my son displayed none of those traits. His OCD is all about thoughts. Anxious thoughts that bombard his mind every second of every hour he's awake. Imagine experiencing your worst nightmare 24/7. In order to prove he doesn't like them he has to perform compulsions - some painful, others embarrassing, none of them nice. It's become so debilitating he's missed most of the school year. Basic everyday things like writing can be a battle. It's a far cry from the talented, sociable, healthy boy we had 18 months ago.

Like so many others we chose to keep it to ourselves, covering up his behaviour when we could, making excuses when we couldn't.

Opening up

It's what we did until that meeting with Prince William. I'd been invited to the Heads Together London Marathon launch. I thought it'd be a chance to listen to other people tell their mental health stories. The Duke and Duchess of Cambridge and Prince Harry were going to make an appearance so it was a pretty big event with a large media presence. After the launch, I was taken to an adjoining room. Without warning, the future king appeared behind me and asked why I was running the London Marathon. Amid the surprise, excitement and my desperation to say something, I broke the parental stigma in my mind. I can still hear those words as if someone else was saying them "My son has OCD". It was unfamiliar territory for me. As a presenter, I normally ask the questions. I normally put other people on the spot. But with the boot on the other foot I spoke out. "I'm sorry to hear that Sean. How is it affecting him" William replied. And we proceeded to have a conversation about my son's struggles, like two dads chatting about the challenges of being a parent.

You're not alone

The next day the papers covered the launch extensively and my son's OCD was mentioned. That's when it became clear we were not alone. Parents got in touch about their experiences. We were part of a parental community treading the same precarious and often demoralising path.

Some were just starting out on the journey, having noticed mental health warning signs in their child. Others had reached the denial stage. A feeling of guilt often follows: 'is it my fault?', 'should I have stayed at home?', was a common concern among working parents.

For me it was the worry that Reuben's issues were hereditary and I had passed on faulty genes. I also worried about my son - 'will he be picked on?'. I was wrong. His amazing school friends have turned out to be more understanding than any adult.

Some parents we've met are much further down the parental mental health path, like Normal Lamb MP, who gave us hope that even if mental health problems are lifelong in many cases they can be managed.

We've got a lot to learn, but I do know that if you're a parent of a child with mental health issues you are not alone. Talking about it can help lessen the burden.

After a long wait for the right level of treatment my son is taking small steps in the right direction.

While he takes those steps, I've decided to take the approximately 52 thousand steps it takes to complete the London Marathon to raise money and awareness for YoungMinds and Heads Together. Life was a lot easier for me when I was 14, so I'm happy to sacrifice my knees to start a conversation about mental health.

Sean Fletcher is a journalist and broadcast personality on BBC Countryfile and ITV's Good Morning Britain. He's a YoungMinds London Marathon Runner. This post was originally published on the YoungMinds website. YoungMinds is the UK's leading charity committed to improving the emotional wellbeing and mental health of children and young people.

How to get involved

If you've been inspired by Sean's story, there are ways you get involved and change the conversation on mental health.

1. Support Sean

2. Start the conversation on social media:

Twitter: @Heads_Together

Instagram: Heads_Together

Facebook: @HeadsTogetherCampaign

#HeadsTogether #OkToSay

3. Watch and share the films on the Heads Together YouTube channel.