The Scottish broadcaster has traced his own roots to Ireland and the IRA after wondering about his background before adoption. He says he has suffered a sense of rejection throughout his life.
Working on the ITV special Long Lost Family: Born Without A Trace, Campbell has been pained to follow the stories of foundlings abandoned with no history or identity.
The presenter said he had “moments” of emotion on Long Lost Family, which he tries not to reveal on screen, as he and an expert team try to find the origins of those who had been left “without a trace”.
He said: “I understand, no matter how happy your adoption is, that nagging sense of rejection that many adopted people get.
“I think it’s important to bring those feelings to it and it’s not a conscious decision to bring them or not, I think it just happens
“It’s really difficult because we get wrapped up in the emotions. You get to know somebody and you kind of go with them on it. I’ve had my moments.”
Edinburgh-born Campbell discovered his mother was a Dublin Protestant and his father had family links to the IRA after embarking on a mission to learn about his own family past following his adoption as an infant.
He has said the information passed on to his adoptive family is more than the “void” foundlings face when they want to know more about their origins.
Campbell said: “With my adoption, I had some scant details and my parents were very forthcoming and said, if I ever wanted to know more, they would tell me as much as they could and they would help me in any tracing process.
“I knew the bare bones of it and that’s so much more than any foundling would ever have any chance of doing.
“I think it’s something they’ve lived with since age nought and it’s been a massive eyesore on their psychological landscape, on their inner life.
“I can’t imagine what that’s like.
“I try and take my own feelings and compare them and it’s difficult, it’s completely different.”
Campbell was educated at Edinburgh Academy. His adoptive mother was a psychiatric social worker and his adoptive father a publisher of maps.
After graduating from the University of Aberdeen with a degree in history, Campbell became involved in commercial production for radio. He worked at Northsound Radio in Aberdeen from 1981 to 1985, first as a jingle writer, before going on to host the breakfast show.
The special Long Lost Family programme will air on ITV at 9pm next Monday.