What is the test for determining whether a person is disabled for the purpose of receiving social security benefits?

A person is considered "disabled" for the purpose of receiving social security benefits if he is unable to "engage in any substantial gainful activity by reason of any medically determinable physical or mental impairment which can be expected to result in death or which has lasted or can be expected to last for a continuous period of not less than 12 months." 42 U.S.C. Sec. 423(d)(1)(A). The impairment must result from anatomical, physiological, or psychological abnormalities which are demonstrable by medically acceptable clinical and laboratory techniques. 42 U.S.C. Sec. 423(d)(3); Gallant v. Heckler, 753 F.2d 1450, 1452 (9th Cir.1984). The same standard is used for determining whether a claimant is entitled to SSI benefits. See 42 U.S.C. Sec. 1382(c)(3)(A).