Question about autism.

[LeftishBrit]

5. Mostly it's diagnostic changes, and greater awareness of autism

30 years ago, higher-functioning autistic people might have been regarded as 'maladjusted' or just 'odd', while lower-functioning autistic people might have been regarded as 'mentally handicapped' without further explanation, or as 'childhood psychotics/schizophrenics' (a diagnosis almost never given nowadays).

In 2009, Simon Baron-Cohen and colleagues did a large-scale study in the UK where they assessed people of different ages according to current diagnostic criteria for autism. The proportion who met the current criteria was the same in all age groups (about 1 per cent), suggesting that there was no actual recent rise in incidence. The only difference was that younger people were more likely to have already been diagnosed on the autistic spectrum, whereas older people were more likely to have other diagnoses or none.

Though there is thus no real evidence of a rise, I would suggest that there may be slight influence from another factor. Children, who are extremely premature or ill at birth, have an increased risk of autism. 30 years ago, most such infants did not live long enough to be diagnosed as autistic; nowadays a high proportion do survive and may receive this diagnosis.