What is the test for determining whether a person with severe mental impairments has a disability?

process. Specifically, an affirmative answer at steps one or four (whether the claimant is currently engaged in substantial gainful activity or can perform past relative work), or a negative answer at step two (whether the claimant has an impairment or combination of impairments that is severe), would immediately lead to a finding of non-disability, and the analysis would stop there. Conversely, an affirmative answer at step three (whether the claimant's impairments meet a listing) would immediately lead to a finding of disability, also ending the analysis. Id. See also Garfield v. Schweiker, 732 F.2d 605, 607 n.2 (7th Cir. 1984).