It may be the Bible for shrinks (and yes I know that all too well) but it is also dated. It is also a consensus that many do not agree with but is the official stance. I recommend reading the peer review papers that you might be able to get access through your college library. Sometimes alumni can get access through the college library and not have to pay for subscriptions that go into the thousands per year. If you want a starting point, look into ADHD, ADD, and shades of autism brain scans.