Associations between human oxytocin receptor gene promoter DNA methylation and brain structural connectome in panic disorder in Korea.
Lower peripheral OXTR DNAm levels may be associated with higher symptom severity in panic disorder, but the implications for treatment and clinical practice remain uncertain.
Where it sits
this study against the rest of the oxytocin corpusSummary and findings
This study examined the relationship between peripheral oxytocin receptor gene promoter DNA methylation (OXTR DNAm) and brain structural connectivity in 563 patients with panic disorder (PD) compared to 210 healthy controls. Patients with PD exhibited significantly lower OXTR DNAm levels than healthy controls. Reduced OXTR DNAm was negatively correlated with elevated clinical symptom scores in patients with PD.
Abstract
<h4>Aims</h4>Epigenetic regulation of the oxytocin receptor gene (OXTR), particularly DNA methylation (DNAm), has been linked to insecure attachment, anxiety-related phenotypes, and suicidality. However, its role in panic disorder (PD) and brain network dysfunction remains unclear. This study examined whether peripheral OXTR DNAm and OXTR DNAm-associated structural connectivity are related to clinical symptoms of PD.<h4>Methods</h4>We investigated OXTR DNAm and its structural connectivity in 563 patients with PD and 210 healthy controls (HCs). Peripheral blood OXTR promoter (-934) DNAm was quantified by pyrosequencing. In a neuroimaging subset, diffusion MRI tractography reconstructed the structural connectome. Network-based statistics tested the diagnosis-by-OXTR DNAm and diagnosis-by-clinical symptomatology effects using separation-related life events (SLEs), Anxiety Sensitivity Index-Revised (ASI-R), and the Scale for Suicidal Ideation (SSI). A preliminary bagging ensemble regression model was used to evaluate treatment response prediction.<h4>Results</h4>Patients with PD exhibited significantly lower OXTR DNAm levels than HCs, adjusting for age, sex, education, smoking status, and body mass index. Within PD, reduced OXTR DNAm was significantly negatively correlated with elevated SLEs, ASI-R, and SSI scores. Diagnosis-by-OXTR DNAm interactions revealed reduced connectivity across the hippocampus, amygdala, orbitofrontal, and precentral regions converging on the extended fear network. Importantly, OXTR DNAm-associated connectivity in the orbitofrontal and lateral occipital cortices showed a cross-validated association with the 8-week treatment outcomes.<h4>Conclusion</h4>Lower peripheral OXTR DNAm was associated with higher PD-related symptomatology and altered extended fear network connectivity. These findings suggest that peripheral OXTR DNAm may index aspects of clinical and neural heterogeneity in PD.
Background
The study investigates the role of epigenetic regulation of the oxytocin receptor gene (OXTR) in panic disorder (PD), a condition associated with anxiety and attachment issues. Prior research has linked OXTR DNA methylation to various psychological phenomena, but its specific implications for PD and related brain connectivity have not been fully elucidated. Understanding these associations could provide insights into the biological underpinnings of PD and its symptomatology.
Methods
This study involved a sample of 563 patients diagnosed with panic disorder and 210 healthy controls. OXTR promoter (-934) DNA methylation was quantified using pyrosequencing, while structural connectivity was assessed through diffusion MRI tractography in a neuroimaging subset. The primary outcomes included correlations between OXTR DNA methylation and clinical symptomatology, as well as connectivity patterns across brain regions.
Results
Patients with panic disorder exhibited significantly lower OXTR DNA methylation levels than healthy controls, adjusting for confounding variables. Within the panic disorder group, reduced OXTR DNA methylation was significantly negatively correlated with elevated scores on the Separation-Related Life Events scale, Anxiety Sensitivity Index-Revised, and the Scale for Suicidal Ideation. Diagnosis-by-OXTR DNA methylation interactions revealed reduced connectivity across key brain regions associated with the extended fear network.
Interpretation
The findings suggest that lower OXTR DNA methylation may be linked to greater symptom severity in panic disorder, indicating a potential biomarker for clinical and neural heterogeneity. However, the effect sizes and clinical significance of these associations remain unclear, and the study's observational design limits the ability to draw definitive conclusions about causality. Additionally, the reliance on peripheral measures raises questions about their relevance to central nervous system processes.
Key findings
- Patients with PD exhibited significantly lower OXTR DNAm levels than HCs.
- Reduced OXTR DNAm was significantly negatively correlated with elevated SLEs, ASI-R, and SSI scores.
- OXTR DNAm-associated connectivity in the orbitofrontal and lateral occipital cortices showed a cross-validated association with the 8-week treatment outcomes.
Limitations
- Observational study design limits causal inferences.
- Reliance on peripheral blood samples may not fully represent central nervous system dynamics.
- No specific numeric findings reported in the abstract.