Getting an earlier diagnosis could help a person gain a better understanding of themselves or get medical help.

According to a study in Autism Research, 4657 legally independent autistic adults finds difference in co-occuring conditions between groups of adults who were diagnosed as a child versus adults. 

They also reported lifetime diagnoses of psychiatric conditions at a higher rate, at 3.2 versus 2.8 for people diagnosed during childhood.  

“Experiences of childhood- versus adulthood-diagnosed people are likely to be quite different,” said lead researcher Vanessa Bal, the Karmazin and Lillard Chair in Adult Autism at Rutgers University 

Where studies do not have the required information to differentiate between the groups, trying to generalise the findings, " is going to have crucial implications for research ".