Lucy Todd was overjoyed when she heard she had made the shortlist of a national photographic competition.

However, as an agoraphobic, she knew she couldn't attend the prize-giving ceremony at the Natural History Museum in London last month and had to send her parents in her place.

While they collected her certificate and posed for photoghraphs with the host, Blue Peter vet Tricia Mundy, Lucy, 18, sat at home and waited for updates by text.

At a time when her friends have been expanding their horizons - heading off to university or gap years abroad - Lucy's world has been steadily shrinking.

She can only travel a short distance from her home in West Sussex before panic sets in.

"My heart races, I get hot, the room begins to spin and my legs feel like they can't hold me," she said.

"It's a flight or fight response, and once I get to a certain point there's no return. I can't calm down and the only thing to do is leave."

Lucy's first panic attack was four years ago at Davison High School in Worthing.

She said: "At first I was only suffering attacks in certain classrooms which were upstairs and I thought it might be something to do with climbing the stairs. Then it started happening everywhere."

"I staggered on through the end of Year 10 and tried to go back after the holidays, but I was spending the whole time in the medical room.

"Finally mum said she didn't want to put me through any more, so I started studying at home."

She was able to take part in a pilot scheme run by West Sussex County Council, which enabled her to attend a virtual school', communicating with teachers over the internet.

Close contact Despite her problems, she achieved seven As and three A* at GCSE and had hoped to continue her studies at Worthing College, but that proved a step too far.

Instead, she persuaded the Open University to give her special dispensation to take courses in biology and photography even though she was two years younger than the usual age of entry.

She spends several hours a day studying alone at the home in Salvington Hill, Worthing, which she shares with parents Anne and Keith and 29- year-old brother Joe, who are all teachers.

Facebook and email enables her to keep in close contact with her friends. She said: "It's a very lonely life. My friends are all off at college in different areas of the country and even when they come home I can't go pubbing and clubbing.

Getting treatment has been difficult. She had to drop out of cognitive behaviour therapy sessions at Worthing Hospital because the trips were stressful and were making her condition worse.

Now she is trying a complementary therapy which claims to unblock trapped emotions.

She is optimistic that one day she will beat her phobia, but finds it difficult to predict when that might be.

"I have no idea of any time spans, but I'm working on it." said Lucy.

rachel.wareing@theargus.co.uk