A recent study from Canada has observed higher rates of depression in mothers who have children after the age of 40. The prevalence of depression after delivery was about threefold higher in women aged 40 to 44 years as compared to women aged 30 to 35 years. This relationship was even stronger after controlling for potential confounders, including education level, marital status, and chronic illness (adjusted OR 3.72; 95% CI 2.15 to 6.41).
When the researchers looked only at first-time mothers, the odds of depression in the 40 to 44 years of age group were substantially higher than among women aged 30 to 34 years (aOR 9.51; 95% CI 3.41 to 26.54).
Exactly why older mothers are at increased risk for depression is not fully understood. The authors remark, “This increased risk has been attributed to a variety of factors, such as the perception that older women have more difficult experiences and adjustments to motherhood, and the lack of peer support due to deviations from social norms surrounding maternal age.” This study did not have data regarding the prevalence of fertility problems and infertility treatment, important factors which may also modulate risk for depression in this group of women.
Ruta Nonacs, MD PhD
Muraca GM, Joseph KS. The association between maternal age and depression. J Obstet Gynaecol Can. 2014 Sep;36(9):803-10.