April 12, 2001 14:17: Can't stop washing? Find yourself hoarding things? Or are you forever checking to see if you locked the door or turned off the cooker. Take heart; you are not alone. More than two per cent of the population is trapped in patterns of repetitive thoughts and behaviour ...

WHEN Sue Marsh was a child, she accepted her mother's obsession with cleanliness as normal.

"Her fear was she would contaminate myself and my sister, that other people would come into the house and contaminate us," she recalled.

"As a child, you don't know that it's any different from the normal way families are, to have three baths a day and always have to change into different clothes when you come home from school and get up in the morning.

"We weren't allowed to play with other children. We always had to be squeaky clean if we went out and got dirt on our clothes, it used to cause a great deal of anxiety."

Sue's mother would get up at 3am so she could fit in her cleaning rituals before taking the children to school.

"She would start from one corner of the room until she had done the whole house. If she was interrupted, she would have to start again."

As time went on, Sue was also roped into the cleaning.

"When I was 10 or 11, I fell asleep at school. I remember my teacher asking if there were any problems at home. I just told him what I had to do at home.

"I felt very guilty. I thought they were going to send my mother to a psychiatric hospital and we were going to be put in a care home."

Sue's mother was given some help and treatment, but remained fairly obsessive. "It was a relief to be able to leave home when I was 16. I suddenly realised how much my life had been handicapped. It was like being set free."

These days, Sue is a community mental health nurse with a special interest in obsessive compulsive disorder, or OCD, a disabling condition that leaves more than two per cent of the population trapped in patterns of repetitive thoughts and behaviour.

Famous sufferers are believed to have included reclusive millionaire Howard Hughes, Charles Darwin and Florence Nightingale.

For Steve (not his real name), his obsession is checking. "My OCD problems crept up on me without me realising I was suffering with anything other than being over-conscientious," he said.

"I started worrying about whether I had done my job properly had I locked the doors or switched off the lights? I worried about letting others down, if I made a mistake or caused someone to be injured by my actions.

"I could be at home watching telly and all of a sudden I would have a thought come into my mind. Did I do that, or did I check that? My mind would go over and over with escalating thoughts of what might happen."

With each day filled with worries and restrictions, Steve became exhausted, irritable and despairing.

After 10 years, his wife asked their GP if there was any help available.

Steve received counselling and heard of OCD for the first time.

He was referred to a psycho-educational group, which gave him further help and enabled him to meet other sufferers.

Out of that was born a new East Dorset action and support group called Obsessions Together.

"We all have obsessional traits, but people with OCD have an over-inflated sense of responsibility. They fear catastrophe is going to occur unless they do their rituals," explained Sue.

The most common obsessions are linked to hygiene and checking, but others include hoarding and counting rituals. Sue knows of one sufferer who had to pirouette three times every time he entered or left his house.

Mental health nurse Dave Boardman, who works with youngsters, said: "A third to a half of adults with OCD recognise their condition started in childhood or adolescence. The main age group I tend to pick up is 10 to 12-year-olds, but there are some six-year-olds who have developed OCD."

"If they can get early intervention, they have a better chance of recovering."

l Useful numbers: Obsessive Action helpline 0207 226 4000; British Association of Behavioural and Cognitive Psychotherapists 01254 875277; MIND 0345 660163.