SLC6A4
SLC6A4 serotonin transporter — the molecular target that 2 compounds in the wiki act on.
In one line: The vacuum cleaner for serotonin — blocked by antidepressants to lift mood.
SLC6A4 is the serotonin transporter — the vacuum that clears serotonin (the calm-contentment chemical) after a signal. Antidepressants called SSRIs block this vacuum, so serotonin stays around longer. Over several weeks, this gradually rewires mood circuits and lifts depression and anxiety.
It's important that the effect takes weeks, not hours — the immediate serotonin rise isn't the fix; the slow downstream changes in the brain are. That's why you can't judge an SSRI in a few days.
Some supplements (like saffron, or 5-HTP) nudge serotonin too, but they should never be combined with SSRIs — too much serotonin at once is dangerous (serotonin syndrome).