According to the Swiss law on Assisted Dying, the patient should be capable of "Sound Judgment (Capacity for Decision-Making)", meaning, "the person must be able to understand the nature, purpose, and consequences of their decision. This is the most critical factor in cases involving non-terminal conditions."
If that person is schizophrenic, would that be considered uncapable for consenting and making a sound decision? Or would it increase the chances for their approval ?
So my guess is it would make it much, much less likely for a person to be approved, even if it shouldn't. This is just a guess.
The problem was a diagnosis like that is that once a person is diagnosed, they are no longer credible. Sad? Don't like medications? Think they aren't helping? Hate life? Well... it's not the truth, it's just because you can't perceive things correctly because of a mental health issue. You're sad, but only because you aren't on enough dopamine-blocking sedatives that make you sleep all day; you don't like medications because you lack insight and your disease prevents you from knowing how great they are; think the medications barely do anything? that's due to a lack of good judgment from the disease because big pharma is always great; you only hate life because you aren't taking enough dopamine blocking sedatives. Once you are in that system, every problem is nail that needs to be hammered with big pharma meds that typically make people tired, twitch, and unable to experience sexual pleasure, and if you complain about those meds, the solution is to hit that nail with even more meds.
Often when a person gets a diagnosis like that, if they are in the system in any way, their feelings and experiences are discounted and they are supposed to follow directions. So if you have that disease, either you are seeing a psychiatrist and taking medications and working, and then managing things okay, or you are seeing a psychiatrist and taking medications and not working, in which case society is taking care of you and you will have almost no autonomy which will slowly be taken from you, ripped away inch by inch if you are getting any public benefits, or you don't see a psychiatrist at all and just raw-dog the symptoms, which is awful, but your autonomy and privacy and dignity won't be taken from you (although your symptoms could get so bad that you end up hurting others, so it's risky if you care about others and not hurting them).
But try to look at things from the perspective of people who are practicing euthanasia and helping people to die:
If someone has schizophrenia, and may or may not be perceiving the world correctly, and then you are the clinic that puts them to death, what happens when the person's family finds out and starts complaining? "You killed my _______ (child/mother/father/brother/sister) who was too sick to decide those things! ____ (she/he/they) didn't know any better! You're evil people!"
I don't know the answer on this, but I think if someone got officially diagnosed with a disease like that, and that was the information presented to a clinic, then that clinic would say no, even if the person was stable on medications and not symptomatic, because it would be too risky for a clinic to get involved with.
If, on the other hand, a person approached a clinic for some other medical reason, and the person had schizophrenia but the clinic didn't know, perhaps the clinic would approve because of ignorance?
Suicide leaves friends and family left behind grieving and angry and feeling helpless, so... society hates it because of that, in part, and because of religion, the lies people in society tell each other to feel less bad. But a clinic is always going to have to be prepared for anger and backlash and it just seems so risky to accept someone with that disease. I don't know if it's been done before. I am guessing, I don't know if there's information out there.
You could check with clinics and ask them, but if they hear your voice or learn your name, they may realize you have that disorder and refuse to help you ever.
As someone who doesn't get involved in the mental health system because of bad experiences in which my privacy was taken away, I should also add I have a large bias against the mental health industry and feel like once someone is given an official mental health diagnosis and embraces that, they get treated as "less than" indefinitely, as some second-class person who lacks autonomy and dignity. But I am very biased from having a horrific experience when I was younger. There are possibly people who have good experiences, take medications, don't mind the side-effects, and have happy lives as a result of medications. That certainly was not my experience, but perhaps others have had that happen?