Are you a mobile addict?

For most of us, the mobile phone has become an essential item for keeping in touch.

To some people - those in the vicinity of a too-loud mobile phone user - they are a modern-day annoyance.

But a new academic study today shows one person in three is completely addicted to their mobile phone.

The biggest study yet of mobile phone usage has discovered that millions of us believe we can't live without our mobiles - almost double the number of phone addicts reported in a similar study last year.

And the survey of more than 150,000 people pinpointed five distinct types of phone user - from the addicted "cyborg" to the "m-ager", a new generation of phone-addicted teenagers.

Researchers found the worst-affected addicts are unable to cope if they are more than six feet away from their phone. They use it as a watch and alarm clock and send dozens of text messages every day.

According to University of Lancaster Professor Mike Hulme, who carried out the study for consultancy firm Teleconomy, the results could be only the tip of the iceberg.

He said: "We have carried out this study every year for four years and this is a very dramatic rise. We were surprised by how many people couldn't cope without their phone. We also saw, for the first time, a whole generation of young, mobile-literate people who are the phone addicts of the future.

"They are into having the latest handsets and personalising their phone as much as they can.

"We even came across a one-year-old who couldn't talk but could distinguish between the ringtones on his mother's phone; he knew when a text message was coming in as opposed to a call."

Professor Hulme also discovered another 18 per cent of us were addicted but refused to admit it.

"The people in denial are the ones the phone companies really love. They sign up to the lowest tariff but then go way over the limit and end up paying large amounts to their phone company. Despite this, they just won't admit they are not in control."

Experts claim our reliance on mobile phones could be permanently harming our ability to communicate with each other.

Psychologist Linda Papadopolous said: "Mobile phones act as a security blanket, which is a good thing, but they do increase our stress levels.

"You feel you are never out of touch and it becomes impossible to sit down to do something; we are always making a call or sending a text. The scale of the addiction is only going to get bigger, particularly with children."