noun
mental disorder; mental illness
A clinical or formal term for a mental disorder or illness. In everyday conversation, 精神障害 or 精神病 are more common; 精神異常 can sound dated or stigmatizing.
See also: 精神障害
精神異常の診断を受けるには専門医の診察が必要です。
A specialist's examination is necessary to receive a diagnosis of mental disorder.
彼は精神異常を理由に裁判で無罪となった。
He was found not guilty in court by reason of mental illness.