Genome-wide association and DNA methylation analyses of SSRI treatment response in major depressive disorder
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Background
Selective serotonin reuptake inhibitors (SSRIs) are first-line treatments for major depressive disorder (MDD); however, patient responses vary significantly. This study explored genetic and epigenetic factors linked to SSRI response to better understand this heterogeneity.
Methods
We performed a genome-wide association study (GWAS) in 852 MDD patients classified as SSRI responders or non-responders. A polygenic risk score (PRS) analysis was conducted to estimate the cumulative effect of common genetic variants. In a subset of 66 participants, genome-wide DNA methylation profiling was carried out using the Illumina Methylation EPIC array. Analyses included the identification of differentially methylated positions (DMPs) and regions (DMRs), as well as weighted gene co-methylation network analysis (WGCNA) and downstream pathway and protein–protein interaction (PPI) analyses.
Results
GWAS revealed several loci with suggestive associations, including intronic variants in SRCIN1 and NKAIN3, although none reached genome-wide significance. The PRS explained a small proportion of variance in SSRI response and did not yield statistically significant results. DNA methylation analysis identified nominally differentially methylated CpGs in genes involved in synaptic signaling and neurodevelopment (e.g., OLFM1, PTN, CACNB2, LHX6). In addition, WGCNA identified a co-methylation module that showed a trend-level association with SSRI response after adjustment for clinical covariates, and hub genes within this module were functionally linked to neuronal signaling in PPI network analysis.
Conclusions
Although no single marker reached significance, the results suggest that synaptic plasticity and neurodevelopment may influence SSRI response. These genomic and epigenomic insights offer molecular clues that may inform future studies on the biological mechanisms underlying antidepressant response.
Selective serotonin reuptake inhibitors (SSRIs) are first-line treatments for major depressive disorder (MDD); however, patient responses vary significantly. This study explored genetic and epigenetic factors linked to SSRI response to better understand this heterogeneity.
Methods
We performed a genome-wide association study (GWAS) in 852 MDD patients classified as SSRI responders or non-responders. A polygenic risk score (PRS) analysis was conducted to estimate the cumulative effect of common genetic variants. In a subset of 66 participants, genome-wide DNA methylation profiling was carried out using the Illumina Methylation EPIC array. Analyses included the identification of differentially methylated positions (DMPs) and regions (DMRs), as well as weighted gene co-methylation network analysis (WGCNA) and downstream pathway and protein–protein interaction (PPI) analyses.
Results
GWAS revealed several loci with suggestive associations, including intronic variants in SRCIN1 and NKAIN3, although none reached genome-wide significance. The PRS explained a small proportion of variance in SSRI response and did not yield statistically significant results. DNA methylation analysis identified nominally differentially methylated CpGs in genes involved in synaptic signaling and neurodevelopment (e.g., OLFM1, PTN, CACNB2, LHX6). In addition, WGCNA identified a co-methylation module that showed a trend-level association with SSRI response after adjustment for clinical covariates, and hub genes within this module were functionally linked to neuronal signaling in PPI network analysis.
Conclusions
Although no single marker reached significance, the results suggest that synaptic plasticity and neurodevelopment may influence SSRI response. These genomic and epigenomic insights offer molecular clues that may inform future studies on the biological mechanisms underlying antidepressant response.
Date Issued
2025-10-28
Date Acceptance
2025-10-01
Citation
BMC Psychiatry, 2025, 25
ISSN
1471-244X
Publisher
BMC
Journal / Book Title
BMC Psychiatry
Volume
25
Copyright Statement
© The Author(s) 2025. Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/41152819
PII: 10.1186/s12888-025-07502-y
Subjects
DNA methylation
Genome-wide association study
Major depressive disorder
SSRI treatment response
Synaptic signaling
Publication Status
Published
Coverage Spatial
England
Article Number
1030
Date Publish Online
2025-10-28