It is a bright, crisp morning in a pub in West London and Adrian Edmondson is looking dapper in jeans and plush drape coat. The 51-year-old could easily pass for, ooh, 49, which is fortunate, as this is the age that he is supposed to be in his new sitcom, Teenage Kicks. “Ah yes,” he sighs and sucks in his tummy. “I think I can carry off playing someone a bit younger.”

The comedian, who made his name as the head-banging Vyvyan in The Young Ones, has come full circle. More than a quarter of a century on, he is back living in student digs, this time as Vernon, an ageing punk who moves in with his undergraduate son and daughter when his wife leaves him. A crucial difference, of course, is that the students in Teenage Kicks are nothing like the undergrads at Vyvyan's Scumbag College, circa 1982. Edmondson sips his tea and gets misty-eyed. “They seem a lot less exciting than in my day. There is not the kind of freedom we had when we were paid to have fun at the Government's expense.” The Young Ones almost wrote itself. “We were grotesque versions of ourselves. I was a bit of a drunk, Rik Mayall was a pretentious wannabe radical, Nigel Planer was a hippy...”

Edmondson continued to have fun after leaving Manchester University as part of the pioneering alternative comedy spearhead. Earlier this year he made a tabloid splash when he talked about his cocaine use, saying that Jennifer Saunders told him to stop taking it because it was making him “act like a tit”. It was way in the past, he explains. “It was actually before we were married. I wasn't even that wild. I wasn't an addict, it was just what you did.”

There are no more drugs and he has even cut back on the beer, though he has not opted for a cardigan and slippers just yet. “It's trying not to be fat that alters your lifestyle the most. I'm not a social drinker, I'm a social event drinker. If it's someone's birthday I get trashed and have a bloody brilliant time.” He once drove into a Soho lamppost and still has a grudge against the West End. “I kicked a taxi the other day in Old Compton Street,” he says with a hint of pride.

So is Vernon just Vyvyan with less hair and more belly? “No, he is actually much more me now. Vernon is very Rock Against Racism, the kind of lefty who proved his credentials by living in a squat with a blocked toilet but went home to his parents in God-alming at weekends to have a poo.”

The idea for Teenage Kicks came from Edmondson's time in the Fame Academy house in 2005, when he was finally forced to realise that he was no longer one of the kids. “I mistakenly thought I was being groovy with the young people. Then I discovered that behind my back they called me ‘uncle'. I realised there is no way you can be mates with young people. It's like my kids (Ella, 22, Beattie, 20, Freya, 17) think that there is no way I could know anything about youth culture but I think that I invented it.” Reality TV made him face harsh realities. “I threw away my motorcycle leathers. I accepted I was never going to have a 32-inch waist again.”

Teenage Kicks is hardly revolutionary - it is ITV, after all - but it does tap into the modern predicament of adults refusing to grow up. Could he ever imagine his father, a teacher in the Armed Forces, going to see the Clash? “He wouldn't even let us have Radio 2 on in the car. I left a Led Zeppelin album out once and he left a note saying: ‘Yes, but what does it all mean?' I don't think my dad ever had a pair of jeans. It was all Marks & Spencer slacks in his day.”

After a life in showbiz, Edmondson, who also appears in Holby City as the maverick surgeon Abra Durant, is mellowing just a little. He certainly likes himself more. “I used to be an arrogant t***. I'm a lot more tolerant, but within me there is a rage that sometimes comes out.” Back to the taxi-kicking again. Anything to do with boarding school? “Yes, that kind of deep psychological wounding scars. You don't have to go much further back than that.”

As a result of his upbringing he was a very hands-on parent. “I think of all the things I've done, being a father is what I've tried to be the most successful at.” His two oldest daughters recently left home and he and Saunders have filled the void by returning to London (keeping their Devon farm for weekends) and throwing themselves into work. “I really miss them, since they left home it's been miserable. One week there were chats around the table, the next week there was no one there.”

While Saunders is winding down her performing partnership with Dawn French on their current farewell tour, Edmondson got there first, splitting reasonably amicably with Rik Mayall in 2003. He just wanted to move on. “It's not that I'm not proud of our work together, I just didn't want to do so many w**k gags any more.”

Maybe he really is finally acting his age. Then again maybe not. “We've got a plan that if we both survive into our late sixties we will play a couple of bastards in an old people's home. There are so many things there to hit each other with - Zimmer frames, walking sticks - it could be really funny.”

While he waits for decrepitude, would he ever consider writing with his wife? “No. A lot of comedy writing is about resolving one's own issues and I don't think that it would be right in a marital partnership. In comedy you chew the cud over who you are and pull things out of that, and I think it would be exposing too much. Look at John Cleese and Connie Booth. They wrote Fawlty Towers and then divorced.”

Teenage Kicks, Friday, ITV1, 9.30pm

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