幻を追う[maboroshiwoou] to pursue an illusion
幻影[genei] phantom
幻覚[genkaku] hallucination
幻覚剤[genkakuzai] hallucinogen
幻姿[genshi] apparition

幻視[genshi] visual hallucination
幻想[gensou] illusions
幻想劇[gensougeki] non-realistic drama
幻像[genzou] phantom

陰鬱[inutsu] gloom
鬱積[usseki] accumulation (e.g. of emotions, grievances, etc.)
抗鬱[kouutsu] antidepressant
鬱を散じる[utsuwosanjiru] to chase one's gloom away
鬱陶しい[uttoushii] gloomy (e.g. mood)

鬱病[utsubyou] melancholia
躁鬱[souutsu] manic-depressive (bipolar)
躁鬱病[souutsubyou] manic depression
鬱血[ukketsu] blood congestion
鬱蒼[ussou] thick