WordNet sense 1 (affected with madness or insanity):

crazy, demented, disturbed, mad, sick, unbalanced, unhinged, brainsick

WordNet sense 2 (afflicted with or characteristic of mental derangement):

insane

WordNet sense 3 (having the attention diverted especially because of anxiety):

distrait

WordNet sense 4 (showing a lack of attention or care):

inattentive