This is the best tl;dr I could make, original reduced by 93%. (I'm a bot)

A 1960s idea that serotonin concentrations might be lowered in depression1 had been rejected,2 and in clinical trials the SSRIs lost out to the older tricyclic antidepressants as a treatment for severe depression.

Serotonin mythIn the 1990s, no academic could sell a message about lowered serotonin.

18 There were pointers to a dimensional role for serotonin from the 1970s onwards, with research correlating lowered serotonin metabolite levels with impulsivity leading to suicidality, aggression, and alcoholism.

Extended Summary | FAQ | Theory | Feedback | Top five keywords: serotonin^#1 SSRIs^#2 antidepressant^#3 patient^#4 depression^#5

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