People who suffer from autism are made to feel isolated in many ways - not least as Ann Robinson reports, when diagnosis confirms they are different.

Gunilla Gerland is 34 and has always brushed her teeth twice a day. But every time she has to think about what she is doing. It has never become automatic - every contact with the toothbrush is like her first.

Gunilla is autistic, although this is hard to imagine when one starts talking to her. She writes, lectures, travels, and has good friends. But her problems, though subtle, become more apparent as the conversation continues. "Skills that others take for granted, like brushing your teeth, will never come naturally to me. I would never be able to drive a car - I wouldn't even try to learn. And if I am speaking on the phone, I find it very hard to understand the person if there is any noise in the background" she says.

She has many professional friends from the field of autism but relationships don't come easy either: "I feel I need to be appreciated and useful, though I'm not sure I can distinguish between that and being loved. I don't think I need to actually feel loved".

It was only at the age of 29, after failing in several jobs and being involved in some self-destructive relationships, that she was diagnosed as having high-functioning autism, or Asperger Syndrome. "I read a book in the library about autism and recognised myself in the descriptions. I contacted the professor of child psychiatry who had written the book and after tests, evaluations and looking back through my old school records I was diagnosed. In a way, it was a huge relief to me after all these years of knowing I was different without knowing why. I had always been labelled 'naughty', 'wayward' or 'difficult', and now it was if my reputation was cleared. I had thought all my problems stemmed from being badly brought up, which I was."

"But the diagnosis also made me sad because I spent my childhood desperately wanting to be the same of others and now I knew for sure that I wasn't."

Gunilla had a horrible childhood by any standards. She says rather ruefully that in some ways being autistic was actually an advantage in her own highly dysfunctional family. "My mother never understood how to deal with me when I was a young child. And later she was entirely absorbed in her own problems of the violent relationship with my father, who eventually abandoned her, and in her own alcoholism."

Gunilla could not have been an easy child for any mother to cope with, let alone a battered, unhappy and drunk one. She had a deep fear of new foods which stopped her chewing anything: she would swallow it whole or avoid all but a few staple foods altogether. She was thrown into panic by sudden noises. She had no memory for people, even familiar ones: when her father left home and later returned, she thought it was a new father. Starting playgroup, and later school, were terrifying experiences for her. She had no way of understanding that her mother would pick her up at the end of the day. She developed rituals and found small, enclosed hiding places to help to contain her panic.

She was bullied and exploited throughout her youth because of being different and also because of her inability to react to pain and misery in any outward way. At school, a group of older boys used to take her behind the toilets every day and hit her. She never told anyone or reacted to the blows. Indeed, such was her need for routine that she sought out the boys if a day went by and they forgot to hit her. She thought this was the way things had to be.

When Gunilla was younger, her mother tried to console her when she was panicky or distraught. But it seemed to Gunilla that her mother had no idea of the depths of her despair: "It was like being consoled for having a graze on my nose when in fact I had broken both my legs." The only person with whom she could play or communicate as a child was her older sister, Kerstin, who was so unhappy at home that she left as soon as she could, taking off just days after finishing school.

Gunilla's mother continued drinking. At a formal family gathering to discuss apportioning an inheritance, she came downstairs totally dishevelled and stark naked. Gunilla's reaction to this emotional nightmare was to become even more detached.

Gunilla eventually left home at 16 and moved in with 17-year-old Jon, with whom she had "a kind of comradeship but no real warmth or closeness". Then she lived on her own and linked up with Annie, who persuaded Gunilla to go to Spain with her. In Spain Gunilla met a heroin addict called Miguel, a self-destructive man who was notorious even among addicts. Gunilla also took heroin but soon decided to leave Miguel and return to Stockholm.

Unable to hold down a job because she couldn't get on with people in a "normal" way, she became depressed and took long-term sick leave. Then, while randomly picking out books in the public library; she came across the description of autism that was "like a punch in the stomach" and was eventually to answer the question why she had always felt different.

Gunilla believes autism is a biological condition: "You are born with it or develop it in early childhood, possibly because of an infection while in the womb or in the early day of life."'

Would she consider having children herself? Yes - if she could find the right partner. "In some ways I'd be a better mother to a child with Asperger's Syndrome than to a normal child because I'd understand it better. But I'd have to have a partner who could compensate for what I lack, and maybe he wouldn't be happy with me."

Gunilla - fluent in Swedish, English and Spanish - has written a moving autobiographical account of her experiences and she helps others with autism. She finds the Worldwide Web a wonderful way to meet others, especially since social interaction is hard for her. She doesn't want sympathy or any talk of her condition being "devastating" Instead, she wants what most people with a disability want: tolerance and some understanding of what makes her different. "I want to feel good about myself, that's all."