Hello arabianbird: I cannot comment with regard to your question. However I noticed this is your first post here on PC. So... welcome to PsychCentral! I hope you find PC to be of benefit.

Here are links to 2 articles, from PsychCentral's archives, on the general topic of stopping psychiatric medications:

Withdrawing from Psychiatric Medications

Discontinuing Psychiatric Medications: What You Need to Know

I do understand your concern with regard to signing a document that would allow a doctor to hospitalize you against your will. (I presume that would be legal where you live. I doubt it would be where I reside.) Giving someone that kind of power over you is not something to be taken lightly, at least from my perspective. On the other hand, based on what you wrote, it sounds as though perhaps agreeing to something such as this may be necessary if you're going to get off the Invega.

I see you list yourself as being somewhere in Europe. Of course I don't know anything about how things work where you live. If you were here in the U.S. I think what I would suggest would be to contact your local mental health association & perhaps see if there would be a mental health legal advocacy organization, or perhaps an attorney, you could discuss this with as well as perhaps receive some guidance from. Perhaps something similar could be done where you live?

It may be, if you simply can't find a physician who will help you get off of the medication without giving them this kind of authority, you may need to agree to something such as this. But it would be best, I would think, to go into it with the support of a knowledgeable organization or perhaps legal professional. At least those are my thoughts with regard to your post. I wish you well...