How to say "addict" in Japanese

• アディクト
  nounA direct borrowing of English 'addict' covering the same meaning; being less common, it is chiefly a word to recognize rather than the default choice in most contexts.
• 中毒者ちゅうどくしゃ
  nounThe word for the substance-abuse sense: someone addicted to drugs or alcohol. It can also suggest 'junkie', giving it a harsher, more stigmatizing edge than a neutral description.
  その中毒ちゅうどく者しゃは麻薬まやくの過剰摂取かじょうせっしゅで死しんだ。↗

  The addict died from a drug overdose.
• 依存症者いぞんしょうしゃ
  nounTreats addiction as a dependence, the clinical framing of the word; it fits medical or explanatory writing and covers dependence on substances and other things alike.
• 常習者じょうしゅうしゃ
  nounReally means 'habitual offender' — someone who repeats an offense — and its 'addict' sense is secondary; it is seldom the word you want unless the habitual aspect is the point.
  彼かれはヘロインの常習者じょうしゅうしゃだ。↗

  He is a heroin addict.
• 常用者じょうようしゃ
  nounMeans a constant, habitual user — typically of a drug — so the 'addict' gloss is secondary; it is seldom the word you want for 'addict' as such.

For substance addiction use 中毒者; for addiction framed as a dependence, 依存症者; 「アディクト」 is the direct loanword; 常習者 and 常用者 really mean 'habitual offender' and 'constant user' and only loosely cover 'addict'.

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

• アディクトaddict
• 中毒者ちゅうどくしゃaddict
• 依存症者いぞんしょうしゃaddict
• 常習者じょうしゅうしゃhabitual offender
• 常用者じょうようしゃconstant user
• 厨ちゅう(Internet) troll
• 廃人はいじん(game, internet, etc.) addict