The simple serotonergic hypothesis (\"serotonin deficit causes depression\") has been qualified by the evidence. SSRIs work, but their efficacy is related more to neuroplasticity and circuit modulation than to a simple increase in neurotransmitter.
View the study (systematic review) →Serotonin is a precursor of melatonin via N-acetyltransferase; its daytime rhythm modulates nighttime sleep.
View the study (review) →90% of serotonin is produced in intestinal enterochromaffin cells, modulated by the microbiota. Dysbiosis alters synthesis and explains part of the anxiety-depression comorbidity with IBS.
View the study (review) →Modulates the feeling of satiety and eating behaviors; its dysregulation contributes to eating disorders.
View the study (review) →Information, not medical advice. Scientific evidence reflects the quality of the studies.