Moreover, while all this has been going on the serotonin hypothesis has come crashing down.

此外，尽管所有这一切都在进行，但血清素假说已经崩溃。

Without the serotonin hypothesis, doctors are, in this regard, back to square one.

如果没有血清素假说，医生在这方面又回到了原点。

Antidepressants came onto the medical scene in the 1960s in response to the serotonin hypothesis—a belief that a lack of a signalling molecule called serotonin was a leading cause of depression.

抗抑郁药在 1960 年代出现在医学界，以响应血清素假说——一种认为缺乏称为血清素的信号分子是抑郁症的主要原因的信念。