What is the test for impairment in a disability claim?

performing the work that the applicant previously performed and incapable of performing any other substantially gainful employment that exists in the national economy. 42 U.S.C. 423(d). The claimant's impairment must result from "anatomical, physiological, or psychological abnormalities which are demonstrable by medically acceptable clinical and laboratory diagnostic techniques." Drouin v. Sullivan, 966 F.2d 1255, 1257 (9th Cir. 1992).