The cause of the disease is unknown, and it often gets better without treatment.

该疾病的成因不明，而且没有治疗时，往往会对症状有改善。

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People with a depressive illness cannot merely "pull themselves together" and get better. Without treatment, symptoms can last for weeks, months, or years.

有抑郁症的人不仅仅拉没有治疗，症状可能维持数个星期，数月或是数年。

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Results suggest that antibiotics do not improve this aspect and antibiotics are not recommended as an initial treatment for this condition as most people get better without them.

回顾结果指出抗生素可改善这方面的情形，但抗生素仍不被建议当作一开始的治疗，因为大多数的人都可以不需要抗生素而自愈。

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Instead, researchers use these so-called natural-history studies to gain a better understanding of how the disease progresses without treatment and to track different symptoms.

WSJ: Families Push for New Ways to Research Rare Diseases

Heart patients who get standard treatment get better quickly, so it is hard to tell without doing a rigorous trial whether it was due to the new treatment or now.

FORBES: AHA 2010