In the book Anything but typical

What was Jason diagnosed with in the third grade?

Jason was diagnosed with autism in the third grade in the book Anything but Typical.

The story is about an autistic 12-year-old called Jason, who cannot lead his everyday life normally, the way other kids do. He can only be himself online, when he is writing his stories. It is online where he meets a girl, Rebecca, who may become his first and only friend.