"In the U.S., primary responsibility for treatment of this vulnerable and at-risk population falls to state and local governments. The performance of this vital public health function is guided by an array of laws, regulations, policies and budgeting choices, all of which vary markedly from one jurisdiction to the next. As a result, any individual’s likelihood of receiving timely and effective treatment for an acute psychiatric crisis or chronic psychiatric disease depends largely on the state and county where he or she happens to be located when such need arises."   from a study by The Treatment Advocacy Center.

 The "imminent danger to themselves or others" is a criterion defined in State law...in this case, in Oregon. It, in fact, as I mention in my post, often leads to intervention being postponed until the mental illness has reached an extreme crisis level.