A problem here that I think most psychiatrists make is their exact boundary in regard to what they are supposed to do, and I've never actually had anyone give us, as a profession, an accepted answer.
If someone is simply lonely, are we supposed to treat that? Insurance, hospital duty, everything else aside other than our professional ethics, are we supposed to deal with this?
Certainly someone in ER psychiatry shouldn't. IMHO it's a waste of hospital resources. ER psychiatry should be reserved for people in acute need of help and if not referred elsewhere.
Insurance won't pay for something unless it's billable. One could argue that loneliness is a form of adjustment disorder, but most insurance companies as far as I'm aware won't allow you to bill for it.
IMHO these people should be referred for psychotherapy only, and a psychiatrist should only treat for this if he/she sincerely believes the person truly has a form of mental illness. Otherwise they need to be referred elsewhere. Other professions such as counselors are supposed to talk to people and given them therapy if they are not mentally ill. In ER psychiatry, we can certainly refer them to a counselor or other services such as churches, social organizations, etc, but I don't think we should be treating loneliness in and of itself.