Sir Trevor McDonald on the 'awful torment' facing thousands of families with missing loved ones
Watch Emily Knight's report
For the past 11 years, every night before she goes to bed, Julie Stammers has messaged her son Anthony.
"That's my connection now," she says.
His family have not heard from 27-year-old Anthony since he went missing from Colchester in May 2012.
But still his family hope. His mother says she takes each day at a time, hoping there will be a breakthrough.
"There are days, obviously, I don't want to face the day, I don't want to get up," she says.
"I don't sleep very well and if I do sleep, I wake up and go 'Damn, I am in this nightmare," Mrs Stammers tells ITV News.
The enduring hope Mrs Stammers feels is held by thousands of other families with a long-term missing loved-one, all holding onto the possibility they could one day be found.
Anthony's father Rob Stammers adds: "It is hard going... Some days it is almost like surreal.
"If someone said to me one of your children would be missing for 11 years, you couldn't comprehend it," he added.
The family say they are leading a double life.
"You've got to get on and do the every day things you do in life", Mrs Stammers said. "But you're also walking this dual life of missing next to you, which is always there."
Anthony's sister Cathy Stammers describes life as having "a little Anthony-shaped hole in everything that you do".
Since 2012 the family has been supported by the charity Missing People, which is marking its 30th anniversary.
“Missing People are the nicest people you never want to meet,” is how the Stammers family describe the charity.
It was founded in 1993 by the late sisters Janet Newman and Mary Asprey following the high profile case of missing estate agent Suzy Lamplugh.
The sisters saw the trauma the Lamplugh family went through and set up a helpline to provide support for families like them.
Jo Youle, the charity's chief executive, said: "Back in the beginning people had no idea of the devastation that a person going missing causes for a family.
The figures are stark, with one person every 90 seconds going missing. Some 353,000 missing incidents are recorded each year with 170,000 people reported missing.
Sir Trevor McDonald has been patron of the charity since it started in 1993.
"I had no idea of the magnitude of what we were actually dealing with in the beginning," he said.
The broadcaster described the "agony and misery" which he has seen families experience over the decades when a loved one disappears and stays missing.
"It's the not knowing what has happened to them - where they are, are they alive or are they not?" he says.
"What this charity does is give people essential support to people who are caught in this awful torment about not knowing what has happened to a missing relative."
Sir Trevor McDonald spoke to ITV News about his 30-year involvement with Missing People and the lengths families have gone to to find a loved one.
"It has affected me because I have understood, which I never did before, the depth of the problem. Also, I never thought of the sheer numbers of people," says Sir Trevor.
"You never get away from the agony and misery which people share with us when they talk about their missing loved ones."
James Stammers, Anthony's older brother, is training for the London Marathon to fund raise for the charity he calls "a lifeline".
He will run with a photo of his brother on his back-pack.
"[It's to] give back to an organisation that's basically been a genuine and real support network over these last 11 years from my perspective and my parents'. I can't thank Missing People enough," he added.
Behind every family affected by a missing person, there is a heart-breaking story, each unique in its tragedy.
Jennie and Mike Thompson from Cheltenham have not seen their son James for almost 30 years.
"We’re both 80 this year... Time is running out,” Mrs Thompson told ITV News.
Jamie, as he was known, was 20 years old. They wonder if they have grandchildren they don’t know about. “That would be nice,” adds his mother.
Tessa Capon from Peterborough last saw her father when he dropped her off at the school bus stop in 1998.
"It's always on my mind. You walk past someone in the street that could potentially be my dad.
"I don't know what he looks like now - it's been 24 years nearly," Ms Capon says.
Bek Stratfield from Tintagel in Cornwall, last saw her 17-year old son Finn in 2017.
"Finn is in my mind every day. I never stop thinking about him and as Finn's mum I'd never give up on him," Ms Stratfield says.
Through every story of heartache and loss, one thing is a constant: the charity, described as “a lifeline” by so many families.
Anyone with any information about a missing person can contact Missing People
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