Nowadays, the word mental itself is used as a descriptive adjective to identify someone different than normal.
From the blogs.psychcentral.com
Today's reader will be startled and probably offended by its frequent use of the most common racial slur, not merely in conversation but as a descriptive adjective.
From the washingtonpost.com
His descriptive passages are convincing, although adjective-heavy, but the frequent juxtapositions of the spiritual with the risible are disruptive.