Janet, I don't know anything about the Medicaid for disabled adults that you refer to.
But Kat does make a point which is that SSDI and SSI use the same qualifications in terms of approving disability. The Medicaid that you are referring to I assume is administered by the state rather than fed. So it's possible that the state could be using different rules for qualification. eg my difficult child gets SSI/ Medicaid on the basis of the qualification we did several years ago in another state.... which refers to functional ability. The Residential Treatment Center (RTC) which is paid by state authorized Medicaid is a different process and doesn't look at the same qualifiers as SSI. They're looking at psychiatric reports referring to depth of illness, chances of recovery, safety of community, etc.