Internet addiction is as dangerous as other "extreme addictive disorders" including gambling, sex addiction and kleptomania, according to Israeli researchers.

Around 10 per cent of the world's surfers are afflicted with this " pathological condition" that can lead to anxiety and severe depression, warned Dr Pinhas Dannon, a psychiatrist from Tel Aviv University's Sackler Faculty of Medicine.

Dr Dannon noted that internet addiction is currently classified by mental health professionals as an obsessive compulsive disorder.

This is a mild to severe mental health condition that results in an urge to engage in ritualistic thoughts and behaviour, such as excessive hand washing or, in the case of the internet, web surfing.

"We need to look at internet addiction differently," said Dr Dannon on behalf of his colleagues from Tel Aviv University and the Be'er Ya'acov Mental Health Center.

"Internet addiction is not manifesting itself as an 'urge'. It is more than that. It is a deep 'craving'. And if we do not make a change in the way we classify internet addiction, we will not be able to treat it in the proper way. "

Two groups are at greatest risk from internet addiction disorder, according to Dr Dannon. The first is teenagers. But more surprisingly, the second is women and men in their mid-50s suffering from the loneliness of an "empty nest".

The symptoms of internet addiction in both groups are vague and often difficult to diagnose. Sufferers may experience loss of sleep, anxiety when not online, isolation from family and peer groups, loss of work and periods of deep depression.

Treating internet addiction can only be done effectively if the condition is treated like any other "extreme and menacing addiction".

For example, a clinician could use talk therapy or prescribe medication such as Serotonin blockers and Naltrexone, which are also effective against kleptomania and pathological gambling.

No less important, Dr Dannon stressed, is that mental health practitioners in schools and workplaces should be made aware of the risks of internet addiction. Workshops on these risks should be held in both situations, he advises.