Hi, and I hope you are well.
You have asked a question that raises a classic dilemma, for many.
The law states you must disclose this for licensing purposes, or you are breaking the law itself. This means you have no choice, when you make an application.
It is possible you will pay a high price for your honesty, however, in terms of potential denial of ratings, time and money.
Supportive medical advice would be to consult your own treating Doctors for advice and remedy to align your condition and general health with that which the Authority will require. I.e. confront the issue head on.
A useful resource is also the CAA medical website that actually shows you medical conditions and what is required for ongoing maintenance of a rating, AND for initial issue. In theory, if you can demonstrate you have complied, then there would be no grounds for denying you a rating.
My advice is to be honest, but be even better prepared, and help yourself.
Just be warned that in the UK the licensing authority can be a total nightmare at times. Check everything before they see it, or you will waste a lot of time!
Best,
F&B