Kind of interesting that the system is different in the UK and people can talk about suicidal ideation relatively more freely than they can in the US.
In the US if you want to avoid involuntary hospitalization, you have to avoid telling them having any specific plans or thoughts. Don't tell them you are on a suicide forum. Don't say that you have searched for methods on the internet. If you have actually done anything, don't tell them that. But I would say that it is just really difficult to openly talk about suicidal ideation with a therapist. Especially if you don't know them very well, you might want to stay away from saying anything directly about suicide.
Before I read one person on this forum saying that you can try saying "depression" instead of "suicide".
Kind of redundant, but I'll write down few things I know of.
-don't mention you know about any specific chemicals, like SN or N
- don't talk about how you want to kill yourself. Ex) hanging, jumping, chemicals, etc. "how are you planning to kill yourself?" Say, "i don't know!"
- don't tell them you've actually done anything to kill yourself. (It would be ok if you've done things long ago, but you are going to make them think that you don't think of Doing things to kill yourself all now)
- don't tell them you used the internet to find ways to suicide. Ex. Don't tell them you searched for painless ways to die on google
If they believe you are an imminent threat to yourself, they are required to seek emergency help for you. If they think you are not an imminent threat to yourself, you might be able to get away with talking about your suicidal ideation. You have to prove them that. However, different mental health practitioners might have different ideas on what makes a person an imminent threat to oneself, so you always have to be careful when you are talking about wanting to harm yourself.
They are also trained to pick up subtle nuances, so I'm just going to say that you really have to be extra careful.