(Wired) – Research reveals that those diagnosed with autism early show distinct genetic and developmental profiles from those diagnosed later.

The analysis, published last week in the journal Nature, showed that children diagnosed before the age of 6 were more likely to have behavioral difficulties—such as problems with social interaction—from an early age. In contrast, those diagnosed after the age of 10 were more likely to experience social and behavioral difficulties during adolescence. They also had a greater predisposition to mental health conditions, such as depression.

The study adds that the average genetic profile of those diagnosed later was closer to that of ADHD and conditions such as post-traumatic stress disorder than to that of “classic” autism identified in early childhood.

The study concludes that the timing of diagnosis is not entirely random but reflects underlying genetic differences that, in some cases, coincide with risk for other conditions. (Read More)