WordNet (r) 3.0 (2006):

cast down
    v 1: lower someone's spirits; make downhearted; "These news
         depressed her"; "The bad state of her child's health
         demoralizes her" [syn: depress, deject, cast down,
         get down, dismay, dispirit, demoralize,
         demoralise] [ant: elate, intoxicate, lift up, pick
         up, uplift]

Moby Thesaurus II by Grady Ward, 1.0:

159 Moby Thesaurus words for "cast down":
   abase, abash, abashed, afflicted, agitated, bad, baffle, balk,
   beat down, beset, bilk, blow down, blow over, bothered, bowed-down,
   bowl down, bowl over, break down, bring down, bulldog, bulldoze,
   burn down, chagrin, chagrined, chapfallen, chop down, confound,
   confuse, confused, crestfallen, cross, cut down, damp, dampen,
   dampen the spirits, darken, dash, dash down, dashed, debase, deck,
   defeat, defeat expectation, degrade, deject, dejected, demean,
   depress, depressed, despairing, despondent, desponding, disappoint,
   discomfit, discomfited, discomforted, discompose, discomposed,
   disconcert, disconcerted, disconsolate, discourage, discouraged,
   dishearten, disheartened, disillusion, dispirit, dispirited,
   disquieted, dissatisfy, distressed, disturbed, down, downcast,
   downhearted, drooping, droopy, drop, embarrass, embarrassed,
   feeling low, fell, fetch down, flatten, floor, foil, frustrate,
   ground, heartless, hew down, humiliate, hung up, hypochondriac,
   hypochondriacal, ill at ease, in low spirits, in the depths,
   in the doldrums, in the dumps, knock down, knock over, languishing,
   lay level, lay low, lay out, let down, level, low, low-spirited,
   lower, lower the spirits, mortified, mortify, mow down, oppress,
   out of countenance, perturbed, pessimistic, pining, precipitate,
   press down, prostrate, pull down, put out, put-out, put-upon, rase,
   raze, sadden, send headlong, sink, smash, spiritless, spread-eagle,
   steamroller, subdued, suicidal, supinate, take down, tantalize,
   tear down, tease, throw, throw down, throw into confusion, thwart,
   topple, trip, troubled, tumble, uncomfortable, uneasy, upset,
   weary of life, weigh heavy upon, weigh upon, whack down, woebegone,
   world-weary