Two key meta-analyses show that 88-93% of people taking SSRIs get no benefit beyond placebo. Yet your doctor probably doesn't know why.

When cortisol sensitivity is shot (common after chronic stress), the serotonin system can't regulate itself properly and shuts down serotonin release early. The expected rise in serotonin doesn’t happen.

When inflammation is elevated, your body actively steals serotonin precursors and blocks serotonin’s effect on neuroplasticity (no neuroplasticity = no anti-depressant effect).

Basic testing can predict this. But 'standard of care' skips them entirely and goes straight to powerful drugs.

The good news? Once you understand what serotonin actually evolved to do, there are much smarter ways to support it.