Effects of major depression and bipolar disorder on erectile dysfunction: a two-sample mendelian randomization study

Area of Science:

• Psychiatry and Mental Health
• Urology and Sexual Health
• Genetic Epidemiology

Background:

• The relationship between major depression (MD) and bipolar disorder (BD) with erectile dysfunction (ED) remains unclear.
• Existing research lacks definitive conclusions on whether these mental health conditions causally influence ED.
• Understanding these potential links is crucial for comprehensive patient care.

Purpose of the Study:

• To investigate the potential causal associations between major depression (MD) and bipolar disorder (BD) and the incidence of erectile dysfunction (ED).
• To utilize Mendelian randomization (MR) analysis to assess these genetic links.
• To clarify the etiological relationship between specific mental disorders and ED.

Main Methods:

• Mendelian randomization (MR) analysis was employed using single-nucleotide polymorphisms (SNPs) from large genome-wide association study (GWAS) datasets.
• Instrumental variables (IVs) for MD and BD were selected to evaluate their genetically predicted relationship with ED incidence.
• Random-effects inverse-variance weighted (IVW) method was the primary analysis, supplemented by sensitivity analyses (Cochran's Q, MR-Egger, MR-PRESSO) to ensure robustness and rule out pleiotropy.

Main Results:

• Genetically predicted major depression (MD) was found to be causally associated with an increased incidence of erectile dysfunction (ED) (OR, 1.53; P = 0.001).
• No significant causal relationship was observed between genetically predicted bipolar disorder (BD) and the risk of ED (OR = 0.95; P = 0.306).
• Sensitivity analyses confirmed the main findings and indicated no significant directional pleiotropy.

Conclusions:

• This study provides evidence for a causal link between major depression (MD) and erectile dysfunction (ED).
• No causal relationship between bipolar disorder (BD) and erectile dysfunction (ED) was identified in the studied European populations.
• Findings suggest distinct etiological pathways for ED in relation to different psychiatric disorders.