Cesta CE, et al. – Using quantitative genetic methods, the researchers intended to quantify and decompose the correlation between neuroticism, polycystic ovary syndrome (PCOS), and major depressive disorder (MDD) into shared and unique genetic and environmental etiologies. Findings revealed that there are common genetic factors between neuroticism, PCOS, and MDD, though, neuroticism shares approximately half of the genetic and environmental components behind the phenotypic relationship between PCOS and MDD, providing some etiological evidence behind the comorbidity between PCOS and depression.

Methods

• In a cohort of twelve thousand six hundred twenty eight Swedish female twins born from 1959 to 1985, neuroticism, PCOS identified by symptoms of hyperandrogenemia (i.e., hirsutism) and oligo- and/or anovulation, and lifetime MDD status were determined through questionnaire responses.
• Structural equation modeling was utilized to examine the genetic and environmental sources of the variation within, and covariation between neuroticism, PCOS, and MDD.

Results

• The results of this study showed that female twins with PCOS (n = 752) had significantly higher levels of neuroticism than women without PCOS, and a 2-fold increase in odds for a lifetime prevalence of MDD.
• It was observed in the findings that the phenotypic correlation between PCOS and MDD was 0.19, with 63% of the correlation attributable to common genetic factors between the two traits.
• When taking into account neuroticism, forty-one percent was attributable to common genetic factors and nine percent attributable to common environmental factors shared between all three traits, with the remainder attributable to components unique to PCOS and MDD.