Autism is a developmental disorder, so any case severe enough to need large amounts of social support will generally get diagnosed before people start trying to

Autism is a developmental disorder, so any case severe enough to need large amounts of social support will generally get diagnosed before people start trying to rig the system (Munchausen by Proxy cases excepted, of course). You can get an adult diagnosis of autism spectrum, and they'll ask about your childhood, but it's not currently worthwhile to verify via interviewing your parents. Also, social security disability benefits for autism are difficult to obtain without a childhood diagnosis. Basically the thinking is that if you weren't disabled enough for your parents to need help getting you through school, you're not disabled enough to be unable to work. This really sucks for the edge cases that fall through the gap, but does have anti-fraud advantages.