It doesn't work like that as PIP isn't awarded on the basis of a disability, it's awarded on the basis of how the disability affects day-to-day functioning.
Not exactly and make a claim on that basis you would most likely fail.
PIP is made up of various descriptors that the government came up with would constitute being disabled.
You don't actually need a diagnosis of what the problem is only some evidence of the difficulties that it poses you on a day to day basis.
Take a claim based on being depressed. You would have to fit enough of the various descriptors that would match the difficulties you have with living with depression.
There is the overall test that even if you could manage a scenario like making a simple meal for one, if you could not do it to a satisfactory level, or that you could not do it again within a reasonable time frame or you did get halfway through the task but had to give up then you could not make such a meal and for that you would be awarded full points for that descriptor.
The descriptors produce points. You have to score a minimum of 8 points for the standard award and over 12 points for the enhanced award.
If you had to use a stick to help with mobilising, you used an aid such as a long handled brush to clean your back in the bath, you had an aid in the kitchen to help with cutting up vegetables and an aid to make sure you took the right medication you would get 8 points. Each aid used awards 2 points. An aid to putting shoes on is also an aid.