Peripheral serotonin levels as a predictor of antidepressant treatment response: A systematic review.

There are currently no reliable biomarkers to predict clinical response to pharmacological treatments of depressive disorders. Peripheral blood 5-hydroxytryptamine (5-HT; serotonin) has been suggested as a biomarker of antidepressant treatment response, but there has not been an attempt to systematically summarize and evaluate the scientific evidence of this hypothesis. In this systematic review we searched MEDLINE, Embase, PsycINFO, and the Cochrane Central Register of Controlled Trials. Twenty-six relevant studies investigating peripheral 5-HT as an antidepressant biomarker were identified. In all, we did not find robust support for an association between baseline 5-HT and treatment response. Several larger studies with lower risk of bias, however, showed that higher baseline 5-HT was associated with a greater antidepressant response to SSRIs, prompting future studies to investigate this hypothesis. Our results also confirm previous reports that SSRI treatment is associated with a decrease in peripheral 5-HT levels; however, we were not able to confirm that larger decreases of 5-HT are associated with better treatment outcome as results were inconclusive.
Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Amanda Holck reports financial support was provided by Southern Health Care Region, Sweden. Asa Westrin reports financial support was provided by Swedish governmental funding of clinical research (ALF). Daniel Lindqvist reports financial support was provided by Swedish governmental funding of clinical research (ALF). Daniel Lindqvist reports financial support was provided by Swedish Research Council. Owen M. Wolkowitz reports financial support was provided by Tinberg Fanily (gift). Pouya Movahed reports a relationship with H Lundbeck AB that includes: speaking and lecture fees. Marie Asp reports a relationship with H Lundbeck AB that includes: speaking and lecture fees. Daniel Lindqvist reports a relationship with H Lundbeck AB that includes: speaking and lecture fees. Daniel Lindqvist reports a relationship with Janssen Cilag AB that includes: speaking and lecture fees. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023. Published by Elsevier Inc.)