1,2,3,4-Tetrahydro-chromeno\x9b3,4-c!pyridin-5-ones of the formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.5 include hydrogen, alkyl, alkoxy, hydroxy, halo, nitro, amino, and trifluoromethyl; R.sub.4 is unsubstituted or substituted phenyl, pyridyl, or quinolinyl; and n is 0 to 4, are useful to treat psychosis in mammals, particularly schizophrenia.