Replying to New analysis finds that depression may not be caused by lower levels of serotinin in the brain.

A large scale study recently concluded which compared levels of serotonin and its breakdown products in the blood or brain fluids did not find a difference between people diagnosed with depression and healthy control (comparison) participants.

After decades of study, there remains no clear evidence that serotonin
levels or serotonin activity are responsible for depression, according
to a major review of prior research led by UCL scientists.

Interesting considering the US 224 million Selective serotonin reuptake inhibitors (SSRI) prescriptions.



Source: https://www.sciencedaily.com/releases/2022/07/220720080145.htm