To what extent do mental health professionals investigate when they suspect persecutory delusions?

In My Humble Opinion
1

Posted in IMHO because it involves the behavior of regulated professions. The example comes out of my imagination and is not real.

To what extent do mental health professionals in the US or similar country investigate the evidence when they suspect persecutory delusions?

E.g. a patient states that he is afraid of entering a nearby town because his ex-wife is Chief of Police and he is afraid that if he enters the town, he will be trailed by police, constantly monitored, persistently cited for trivialities that he then would have to pay to defend against (one mile over speed limit, jaywalking, littering etc.), and potentially brought to trial on trumped up or outright falsified charges? This fear of the town causes problems for the patient because his normal commute takes him past the town and he now spends an extra hour to drive around the town, making care to stay at least 100 feet from the town limit line, during his daily commute, which adds to his stress and exhaustion (potentially clinially significant distress).

Would a clinician automatically assume that the fear must be unreasonable and delusional because American cops are never corrupt? To what extent would the clinician go to determine whether or not there is any external evidence that the town’s police are corrupt before stamping the patient as delusional?

Similarly, a patient could fear retaliation from organized crime or something similar that could possibly be true but, for the majority of people, isn’t.

2

Obtaining collateral info from the patient’s family and friends is a big part of mental health care. It would be standard practice in that kind of situation for a psychiatrist to try to confirm what’s been going on with other people who know the patient (if the patient will grant permission for the psychiatrist to talk to others).

Of course, the only situation in which you can force psychiatric treatment on someone in most locales is if their behavior appears to be IMMINENTLY DANGEROUS to either themselves or others. If someone has a strange belief, but it appears to be harmless, the only reason they would have to talk to a psychiatrist about it would be if the person having the odd belief found it troubling. So this person, who is avoiding the city and not expressing any desire to retaliate against his ex-wife, would probably never end up talking to a psychiatrist about this odd belief unless he himself recognized it was irrational and wanted help to stop thinking about it.
Trust me, there are a lot of people walking around out there with active psychosis who aren’t under treatment because they haven’t expressed anything dangerous.