S.S.R.I.s are designed to help keep serotonin, a brain chemical, at a continuous level.The new study suggests that they provide little help to the large majority of the millions who take them.

• s用来使大脑中的化学物质复合胺持续保持某个水平.；这项新的研究指出这些药物对于大多数的使用者都是无效的