The Time to Change campaign says one in four have a mental illness. If it is one in four, then there are still 170 to go in the Commons. You still have the stigma, otherwise you would not have just four MPs.
British politician Charles Walker, on ‘coming out’ in the House of Commons as having struggled with severe OCD for over 30 years by referring to himself as a “fruitcake”.
I totally agree with this: self-define how you like, especially if humour is your coping mechanism - just don’t use labels for others unless you have their consent and agreement that that is how they identify. (‘Mad pride’: proceed with caution).