Nǐ bié shénjīng shīcháng le, shìqing méi nàme yánzhòng.
Don't lose it — things aren't that serious.
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Colloquial. Often used hyperbolically (like English 'losing it') rather than as a clinical diagnosis. The medical term for psychiatric illness is 精神病 (jīngshénbìng) or 精神障碍 (jīngshén zhàng'ài).
