Skeezys - many thanks for those links, I'll work my way through them.

Dnester- appreciate the thought, thank you

magicalprince - yes we asked, but he denied feeling truly suicidal. He admitted feeling hopeless and that everything felt pointless. He seems to have his own internal narrative which differs from ours (perhaps reality is somewhere in the middle?). He's really smart, scarily so... but we've never expected him or his sister to do more than their best. As long as He's tried his best, that's enough. He seems to have his own internal "I must be perfect" thing with no room to learn or grow from mistakes - he just mentally tortures himself.

He expects us to react badly and punish him if he does poorly at school. Which we don't deserve - we walk on eggshells around him. I'm sure we're not perfect parents, but he often veers from "fear of us punishing him" to being angry at us not being strict enough!! It's confusing!

His sister by the way, who has never got as high grades as him academically is a sea of zen-like calm.