No standing
Love does not confer standing.
Most of what people assume they can do from this position does not exist. The short list of what genuinely does is more useful than the long list of what does not.
Why nobody will tell you anything
You are not next of kin. That single fact governs most of what you run into, and it is why the position feels like being shut out of something you are clearly in the middle of.
- A hospital or a doctor will not discuss him with you, will not confirm he is there, and is not being obstructive — it is confidentiality, and it applies whatever you know about him.
- A treatment service will not tell you whether he arrived, stayed, or left.
- You cannot have him admitted anywhere, and you cannot make anybody assess him. Where compulsory assessment exists it is judged by clinicians under law, not requested by a friend.
- You are frequently the last person to be told what happened and, if it goes badly, the first to be asked why you did not do more.
Rules vary by country and this site does not give legal advice. What is consistent is that love does not confer standing, and no amount of being the one he talks to changes that.
What you can still do
A shorter list than people expect, and not an empty one.
- You can call an ambulance to him. Nobody needs to be a relative for that, and it is the one lever that works at any hour, from any distance.
- You can pass information in even where none comes out. You can tell a service what you have seen, and they can listen to you without telling you anything back. It is not futile and it is often the only way a clinician hears the unsanitised version.
- You can report a child at risk, or somebody being hurt in that house, and you do not need proof, certainty or his permission. The routes are here.
- You can be a stable fact. Answering on Sundays, not lying to him, not joining in. It is unglamorous and it is what people credit years later.
- You can decline to lie for him, to lend money, to keep a dangerous secret, or to be the only person who knows.
What is not a lever, whatever you are told
Ultimatums delivered by somebody with no standing are usually absorbed and forgotten. Confrontation meetings need a trained person in the room. Getting several people to send the same message at once tends to produce a closed door rather than a decision.
And the thing people most often try: being reliably, endlessly available in the hope that presence eventually converts into change. It does not work as a mechanism, it is not repaid, and it is the single most common way people in your position end up unwell themselves.
If he has told you and nobody else
That is common and it has a logic: the person furthest from the consequences is the safest one to tell. It is not a mandate, and you did not accept a role by picking up.
You are allowed to say that you cannot be the only one who knows. Asking him to tell one other person, or telling him you intend to speak to somebody yourself, is honest rather than a betrayal — and saying it sober, in advance, is the version that does not break the relationship.
Where safety is involved, the calculation changes and secrecy is not an option. If a child is at risk or somebody is being hurt, the route comes before the friendship.