The relationship between neuroticism and inflammatory markers: a twin study

Area of Science:

• Behavioral genetics
• Psychiatric genetics
• Immunology

Background:

• Neuroticism is a vulnerability marker for mental and physical disorders.
• Inflammatory markers (CRP, fibrinogen, IgG) are linked to similar disorders.
• Shared genetic background between neuroticism and inflammation is unstudied.

Purpose of the Study:

• Investigate the phenotypic and genetic relationship between neuroticism and three inflammatory markers.
• Examine shared genetic and environmental pathways.
• Assess moderation of inflammatory marker regulation by neuroticism.

Main Methods:

• Study involved 125 Dutch female twin pairs.
• Neuroticism composite score calculated from four measures.
• Heritabilities, phenotypic, and genetic correlations estimated using bivariate structural equation modeling.

Main Results:

• Substantial heritabilities observed for neuroticism (0.55), CRP (0.52), fibrinogen (0.67), and IgG (0.43).
• No significant phenotypic or genetic correlations found between neuroticism and inflammatory markers.
• No moderation of genetic/environmental pathways by neuroticism.

Conclusions:

• Neuroticism and inflammatory markers (CRP, fibrinogen, IgG) are substantially heritable.
• No evidence for shared genetic or environmental pathways between neuroticism and inflammation.
• Neuroticism does not appear to moderate inflammatory marker regulation.