A new CDC reports says that 1 in 59 children in 11 studied states are identified as being on the autistic spectrum, up from 1 in 68 just two years previously. But does this mean that the prevalence of autism is increasing? Probably not. Increased screening for and recognition of affected children as well as a broadened definition of the syndrome are probably to blame. Via Neuroscience News
This is emblematic of a larger problem in behavioral science overall, as diagnosis is done by descriptive criteria in the absence of definitive empirical measures. This leads to expansion and contraction of various diagnostic groups (e.g. bipolar disorder or schizophrenia) both over time and from place to place.