first I want to say the APA in your link is for the American Psychological Association which is different than the APA as in the American Psychiatric Association. Even though they both carry the same organization initials, they are two different organizations here in america that do completely different things in different ways. the first one over sees psychologists and the other is much bigger and publishes the DSM (diagnostic manual that says what mental disorders there are in america, the diagnostics and so on, and also governs things testing requirements and much more.)