Once again, there is no legal obligation to give information on a disability or health issue. At all. Same goes for job applications.
Please, don't pay attention to the scaremongering OP. People are talking about different scenarios
Grinch do you teach in a university or train SWs on placement?
Because from my POV as a university tutor, although not in social work, the OP’s situation rings alarm bells for me.
Setting aside legal or professional issues, the catastrophising and overreaction to tutor’s advice and the denial of making a mistake is somewhat problematic.
University stafiwant students to succeed. We don’t set them up to fail. But students need to be “Fit to Practice “ and a suicide attempt resulting in sectioning is serious. And an error of judgement in not disclosing when asked, and maintaining denial now.
You’re right that generally, no-one is obliged by law to declare an il weds/disability but if students need support or mitigation they do have an obligation to disclose.
In my long experience of teaching undergrads the ones who thrive are the ones who take responsibility and develop self-knowledge particularly if they suffer from a chronic illness or fragile health. The ones who tend to crash are those who will not accept help that they need or are in denial that they need support and help.