Wonder if that is counting outside of the capitol complex?
Check it out:

One in three, or 35.2 percent, of people getting federal disability insurance benefits have been diagnosed with a mental disorder, according to the latest data from the Social Security Administration (SSA).

Washington, D.C., the seat of the federal government, ranked in the top-ten list of states where disabled beneficiaries were diagnosed with mental problems.

In 2013, the latest data from SSA show there were 10,228,364 disabled beneficiaries, up 139,625 from 2012 when there were 10,088,739 disabled beneficiaries.