How to say "insanity" in Japanese

• 狂気きょうきCommon
  no-adjectiveMadness or insanity as a state of mind, without insulting force; the natural choice for describing someone's madness or a descent into insanity.
  それをやってみるなんて狂気きょうきに近ちかい。↗

  It is little short of lunacy to try it.
• キチガイCommon
  nounMadness or insanity, or a person regarded as a madman or lunatic; derogatory and offensive, so avoid it unless you mean to insult or disparage. Normally written in kana alone.
  デルバートは気違きちがいだと思おもうよ。↗

  I think that Delbert is crazy.
• 心神喪失しんしんそうしつCommon
  nounInsanity in the sense of lack of mental capacity — being non compos mentis — rather than madness as a state of mind; typical contexts are legal discussions of responsibility for one's actions.

Use 狂気 for madness or insanity as a state of mind, 「キチガイ」 for madness or a madman but with insulting, derogatory force, and 心神喪失 for insanity as lack of mental capacity in legal contexts.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 狂気きょうきmadness
• きちがいmadness
• 心神喪失しんしんそうしつinsanity
• 発狂はっきょうmadness
• 物狂いものぐるいinsanity
• 瘋癲ふうてんinsanity
• 風狂ふうきょうinsanity
• コリンヌクレリーのヌードダンサーInsanity (film)
• 狂いくるいmadness
• 乱心らんしんmental derangement
• 癲狂てんきょうmadness