Oxytocin receptor gene methylation: converging multilevel evidence for a role in social anxiety.

Abstract

Social anxiety disorder (SAD) is a commonly occurring and highly disabling disorder. The neuropeptide oxytocin and its receptor (OXTR) have been implicated in social cognition and behavior. This study-for the first time applying a multilevel epigenetic approach-investigates the role of OXTR gene methylation in categorical, dimensional, and intermediate neuroendocrinological/neural network phenotypes of social anxiety. A total of 110 unmedicated patients with SAD and matched 110 controls were analyzed for OXTR methylation by direct sequencing of sodium bisulfite-converted DNA extracted from whole blood. Furthermore, OXTR methylation was investigated regarding SAD-related traits (Social Phobia Scale (SPS) and Social Interaction Anxiety Scale (SIAS)), salivary cortisol response during the Trier social stress test (TSST), and amygdala responsiveness to social phobia related verbal stimuli using fMRI. Significantly decreased OXTR methylation particularly at CpG Chr3: 8 809 437 was associated with (1) the categorical phenotype of SAD (p<0.001, Cohen's d=0.535), (2) increased SPS and SIAS scores (p<0.001), (3) increased cortisol response to the TSST (p=0.02), and (4) increased amygdala responsiveness during social phobia-related word processing (right: p(corr)<0.001; left: p(corr)=0.005). Assuming that decreased OXTR methylation confers increased OXTR expression, the present finding may reflect a compensatory upregulation for pathologically reduced oxytocin levels or a causally relevant increased OXTR activation in SAD and related traits. OXTR methylation patterns might thus serve as peripheral surrogates of oxytocin tone and aid in establishing accessible biomarkers of SAD risk allowing for indicated preventive interventions and personalized treatment approaches targeting the oxytocin system.

• Authors: Christiane Ziegler, Udo Dannlowski, David Bräuer, Stephan Stevens, Inga Laeger, Hannah Wittmann, Harald Kugel, Christian Dobel, René Hurlemann, Andreas Reif, Klaus-Peter Lesch, Walter Heindel, Clemens Kirschbaum, Volker Arolt, Alexander L Gerlach, Jürgen Hoyer, Jürgen Deckert, Peter Zwanzger, Katharina Domschke
• Journal: Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology (Neuropsychopharmacology) Vol. 40 Issue 6 Pg. 1528-38 (May 2015) ISSN: 1740-634X [Electronic] England
• PMID: 25563749 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• OXTR protein, human
• Receptors, Oxytocin
• Hydrocortisone

Topics

• Adult
• Amygdala (physiopathology)
• Anxiety Disorders (genetics, physiopathology)
• DNA Methylation
• Female
• Genetic Variation
• Humans
• Hydrocortisone (metabolism)
• Magnetic Resonance Imaging
• Male
• Neuropsychological Tests
• Psychiatric Status Rating Scales
• Receptors, Oxytocin (genetics)
• Saliva (metabolism)
• Social Behavior