Good book, but why ignore a plethora of problems like ADHD that might have something to do with the chronic procrastination in a person's life? I just can't go

Good book, but why ignore a plethora of problems like ADHD that might have something to do with the chronic procrastination in a person's life? I just can't go past the first few pages of the book without seeing the fact that most of the symptoms that the author is describing of chronic procrastinators are in fact the exact symptoms that are used to diagnose ADHD in adults. What am I missing?