You know your gaming habit has got out of hand when you start wearing a nappy to allow you precious extra minutes at the screen. So says Brian Dudley, the director of Broadway Lodge in Weston-super-Mare, which earlier this year became the first addiction clinic in the UK to welcome gaming addicts.

"We are now seeing some people devoting their whole lives to gaming," says Dudley, who offers a 12-step abstinence programme to those suffering from a wide range of addictions, including alcohol, drugs and sex. "Some spend 18 hours a day playing on their computers. Immersive role-playing games such as World of Warcraft and Call of Duty hook people and let them live in a fantasy world. The online element to the game lets them falsely believe they have lots of friends. Some people were reported to have taken a week off work just to play Call of Duty when it was released recently."

Dudley's sense of frustration about the lack of action over excessive gaming is palpable: "We're just at the tip of the iceberg in our understanding of this subject. There's been very little in the way of meaningful research. Some research in the US has shown that 8-10% of gamers show signs of addiction, and in places such as South Korea there are now over 100 gaming addiction treatment centres. The industry is in denial about it at the moment and politicians are just not interested."

Ever since videogames became a fixture in our homes in the early 1980s, there has been panic about their effect on our increasingly sedentary population. But with the arrival of broadband earlier this decade, multiplayer, fantasy role-playing games such as World of Warcraft have become hugely popular.

"It's the games with no end that are the worst," says Dudley. "They can help people develop eating disorders, such as binge eating. We're also seeing cross-addiction, where gamblers start to also get addicted to gaming and alcohol. There are many triggers for addiction such as bullying and family problems. But sometimes it can be just that the person really enjoys the game."

But are computer games just a hook for addictive personalities? Without extensive research, it's unlikely we'll ever get a definitive answer, says Dudley. And the gaming industry is dismissive of the notion that gaming could be harmful. The Entertainment and Leisure Software Publishers Association (Elpsa) says: "Playing videogames is simply another daily activity that can give people pleasure. It is not a physical addiction."

Addiction is not the only worry. Since the launch in 2006 of the Nintendo Wii, there have been regular reports of people suffering from injuries during gameplay. But it is injuries caused by repetitive actions – "cumulative trauma disorders" – that seem most likely to manifest themselves during excessive gaming. "It has been shown in the US that kids playing computer games can develop symptoms in their arms and fingers, especially when using a joystick," says Professor Stephen Tyrer, emeritus consultant in psychiatry, pain and neurorehabilitation at Newcastle's Royal Victoria Infirmary. "Kids that really enjoy a game can also develop more symptoms, but after two to three days of not playing, the symptoms tend to go. Aggression and pain have also been strongly related in studies, which might raise questions about there being a link when playing certain games. The most affected part of the body is likely to be the hand and arm, but the tension created when playing could lead to symptoms in the neck, shoulder and elbow. As with any screen-based activity, the advice is to take as many breaks as possible, ideally at least five minutes every hour."

Mike Rawlinson, director general of Elpsa, says that the "industry believes that videogames should be enjoyed as part of a healthy, active and balanced lifestyle". And he points to the fact that in October, the Department of Health's Change4life programme chose to endorse Nintendo's Wii Fit Plus for its health benefits.

It marks quite a departure from a Change4life poster that was distributed across the country back infrom March that . It showed a young boy slouched in front of a screen holding the controller to a games console with the headline: "Risk an early death, just do nothing."