Autism is one of the most devastating — and puzzling — disorders challenging medical science. Now, a McMaster University psychologist has uncovered some precious clues to its beginnings.
Autism includes a wide range of symptoms, but the most important include a withdrawal from social life, problems with language and unusual attachments either to objects or the arrangements of objects.
The diagnosis of autism is usually made when a child is 2 1/2 or 3 years old, but there are reasons to believe the seeds of the disorder are sewn much earlier, perhaps even at birth. The problem is uncovering convincing evidence of that.
So, when Dr. Melissa Rutherford was told by the mother of twins, one of whom was an autistic boy, that she had kept, from the very beginning, a daily journal detailing the twins' health and behaviour, Rutherford realized she had a unique document.
Not only was this an exhaustive record of the boy's daily life before he was diagnosed at the age of 3, but his twin, a girl, served as a control child exposed to the same possible environmental effects that might have played a role in the onset of the condition.
The journal did not disappoint, even from its first pages. For instance, birth difficulties have been linked to the development of autism in the past, and indeed the twins' birth was difficult for both, but much more difficult for the girl, suggesting, at least in this case, that birth problems had not been the decisive factor.
The daily entries showed that six months of age might have been a turning point in the lives of these children. Before that, there was little discernible difference between the two children. They were developing normally and at about the same pace. However, as the twins approached their first birthday, things began to change.
The girl began to use verbal labels for things and people; the boy did not. From the age of 6 months to a year, the boy only used two different words, whereas his sister used several words a week. At every language milestone that followed, the boy lagged further and further behind his sister.
One of the hallmarks of autism is deficient social behaviour. Again in this case such deficits did not appear before 6 months, but soon after became more and more evident as time passed.
By the age of 11 months, the two twins were noticeably different — the girl communicated with others both verbally and non-verbally, but the boy avoided eye contact, displayed less affection for others than did his sister and often failed to respond to his name when called.
By the time he was 2, he preferred to be alone and play by himself. By the age of 3, a child psychiatrist remarked that he "does not offer comfort if others are in distress and will not come for comfort if he himself is hurt" and that he "will not engage in social play." By this time he was well on his way to fulfilling all the diagnostic criteria of autism.
Rutherford argues that there are two important ideas to come from this journal. One is that until the age of 6 months, there were no apparent behavioural differences between the two twins.
What this means isn't clear. It could be that there are signs of incipient autism present, but too subtle for us to detect, at least with current techniques. However, it might also mean that the disorder has not yet set in. Which one is true obviously has huge implications for causes. Are they there from the beginning? Or can the cause be traced to something that happens to the child after birth?
The other clear finding is that, while diagnosis is usually made around the age of 3, there are, at least in this case, clear signs of autism at least two years earlier than that. This suggests that it might be possible to diagnose the condition much earlier and put in place therapies that might improve the outlook for the very young, autistic child.
Not to be greedy, but this story would have been even more fascinating had the twins been identical, thereby exposing the role of genes in the origin of the condition.
Nonetheless, I suspect that much more will come from this document — it will be a reference for autism research for years to come.
Autism includes a wide range of symptoms, but the most important include a withdrawal from social life, problems with language and unusual attachments either to objects or the arrangements of objects.
The diagnosis of autism is usually made when a child is 2 1/2 or 3 years old, but there are reasons to believe the seeds of the disorder are sewn much earlier, perhaps even at birth. The problem is uncovering convincing evidence of that.
So, when Dr. Melissa Rutherford was told by the mother of twins, one of whom was an autistic boy, that she had kept, from the very beginning, a daily journal detailing the twins' health and behaviour, Rutherford realized she had a unique document.
Not only was this an exhaustive record of the boy's daily life before he was diagnosed at the age of 3, but his twin, a girl, served as a control child exposed to the same possible environmental effects that might have played a role in the onset of the condition.
The journal did not disappoint, even from its first pages. For instance, birth difficulties have been linked to the development of autism in the past, and indeed the twins' birth was difficult for both, but much more difficult for the girl, suggesting, at least in this case, that birth problems had not been the decisive factor.
The daily entries showed that six months of age might have been a turning point in the lives of these children. Before that, there was little discernible difference between the two children. They were developing normally and at about the same pace. However, as the twins approached their first birthday, things began to change.
The girl began to use verbal labels for things and people; the boy did not. From the age of 6 months to a year, the boy only used two different words, whereas his sister used several words a week. At every language milestone that followed, the boy lagged further and further behind his sister.
One of the hallmarks of autism is deficient social behaviour. Again in this case such deficits did not appear before 6 months, but soon after became more and more evident as time passed.
By the age of 11 months, the two twins were noticeably different — the girl communicated with others both verbally and non-verbally, but the boy avoided eye contact, displayed less affection for others than did his sister and often failed to respond to his name when called.
By the time he was 2, he preferred to be alone and play by himself. By the age of 3, a child psychiatrist remarked that he "does not offer comfort if others are in distress and will not come for comfort if he himself is hurt" and that he "will not engage in social play." By this time he was well on his way to fulfilling all the diagnostic criteria of autism.
Rutherford argues that there are two important ideas to come from this journal. One is that until the age of 6 months, there were no apparent behavioural differences between the two twins.
What this means isn't clear. It could be that there are signs of incipient autism present, but too subtle for us to detect, at least with current techniques. However, it might also mean that the disorder has not yet set in. Which one is true obviously has huge implications for causes. Are they there from the beginning? Or can the cause be traced to something that happens to the child after birth?
The other clear finding is that, while diagnosis is usually made around the age of 3, there are, at least in this case, clear signs of autism at least two years earlier than that. This suggests that it might be possible to diagnose the condition much earlier and put in place therapies that might improve the outlook for the very young, autistic child.
Not to be greedy, but this story would have been even more fascinating had the twins been identical, thereby exposing the role of genes in the origin of the condition.
Nonetheless, I suspect that much more will come from this document — it will be a reference for autism research for years to come.
posted by kevin at 9:10 AM
