Children are 'under pressure to stay connected 24 hours day'
Using a mobile phone frequently may be associated with teenage stress, a study has found.
It could also be linked to restlessness and sleep-related problems, according to researchers at the Sahlgren Academy in Sweden.
The study looked at two groups of mobile phone users between the ages of 14 and 20 who were categorised by how much they used their phones.
Scientists found those who used them most were more restless.
They were more likely to suffer from stress, fatigue, disrupted sleep and insomnia.
Research leader Dr Gaby Badre said: "Addiction to cell phones is becoming common.
"Youngsters feel a group pressure to remain interconnected and reachable round the clock."
The participants were divided up into those who made less than 5 calls and 5 texts a day and those who made more than 15 calls and sent more than 15 texts.
The more heavily-dependent on a mobile the person was, the more likely they were to adopt a "careless" lifestyle, which included consuming caffeinated drinks and spending more time on computers.
Dr Badre added: "There seems to be a connection between intensive use of cell phones and health-compromising behaviour such as smoking, snuffing and use of alcohol."