Which of the following can help diagnose attention deficit/hyperactivity disorder (AD/HD) according to the American Psychiatric Association?
1) The impairment should be exhibited in multiple settings.
2) The symptoms should persist to a degree that is maladaptive and inconsistent with the individual's developmental level.
3) The behavior should be caused by a temporary situation.
4) The characteristics of AD/HD should be displayed before the age of 20.