The relationship between major depression and migraine: A bidirectional two-sample Mendelian randomization study.

Area of Science:

• Psychiatry
• Neurology
• Genetics

Background:

• Epidemiological studies suggest an association between major depressive disorder (MDD) and migraine.
• The precise causal link between MDD and migraine remains incompletely understood.

Purpose of the Study:

• To investigate the bidirectional causal relationship between MDD and migraine using a two-sample Mendelian randomization (MR) approach.
• To examine the potential causal effect of MDD on migraine subtypes: migraine with aura (MA) and migraine without aura (MO).

Main Methods:

• Utilized genome-wide association study (GWAS) data for MDD and migraine (MA, MO).
• Employed single nucleotide polymorphisms (SNPs) as instrumental variables (IVs) in a bidirectional MR analysis.
• Applied inverse variance weighting (IVW) as the primary analysis, supplemented by MR-Egger, weighted median, and mode methods.
• Conducted heterogeneity, pleiotropy, and leave-one-out sensitivity analyses to ensure result robustness.

Main Results:

• Mendelian randomization analysis indicated a significant causal effect of MDD on increased migraine risk (OR, 1.606; p=1.52E-06).
• MDD was also causally associated with higher risks of MA (OR, 1.400; p=0.015) and MO (OR, 1.814; p=0.0008).
• Reverse MR analysis showed no significant causal effect of migraine (MA, MO) on MDD risk.

Conclusions:

• This study provides robust genetic evidence supporting a causal relationship where MDD increases the risk of developing migraine.
• The findings suggest that MDD is a significant risk factor for both MA and MO.
• No evidence was found for a causal effect of migraine on MDD risk in this genetic analysis.