John Carey was spending a fortune on his 50-a-week habit. It was his only vice but at times of stress he just could not stop himself.

But he was not puffing away on cigarettes or scratching National Lottery cards. He was eating ballpoint pens.

The company where John works made him buy his own because his habit was costing them too much.

So he started stocking up on pens at his local shop at a cost of around £50 a month.

He knew he had to get help so he turned to hypnotherapy.

John, 34, from Brighton, used to munch his way through every part of a pen while he sat in front of his computer and would bite the shaft until it splintered, eat the lid, chew the refill and then throw what remained in the bin.

He said: "My manager took me to one side and said it wasn't just the money I was costing them but the fact that nobody else could ever find a pen to use.

"I've been chewing them for about five years but it started getting worse, especially when I was stressed. Where other people would say 'I'm dying for a cigarette' I'd say 'I'm dying for a pen'.

"A lot of the time I didn't realise I was doing it.

"Once I went to a sales meeting and on the way there in the car I ate a pen. When I walked in I had ink all over my mouth and didn't realise.

"Nobody said anything for a while and then one of them said, 'You've got a bit of ink on your lip.' I looked in a mirror and I had blue all over my face."

John's girlfriend, Penny, had grown used to his bizarre habit. But after one session of hypnosis by students at Uncommon Knowledge, a hypnotherapy clinic in Brighton, John was cured.

Andy Cripps, who hypnotised John, used a scrambling technique. He said: "Basically, we jumbled up the sequence of his habit in his head to break the cycle."

Andy meets fellow hypnotherapy students each week in Worthing to cure people of their phobias - the most common arachnophobia, fear of spiders.

To volunteer to be hypnotised ring him on 07970 918877.