Increased measles seronegativity in adults with major depressive disorder

Abstract

Current and/or recent psychological stress or depression can impair vaccine efficacy. Nevertheless, the relationship between the efficacy of vaccinations received during childhood and depression in adulthood is unclear. Here, we tested for the presence of IgG antibodies against measles in volunteers meeting DSM-IV-TR criteria for current major depressive disorder (dMDD, n = 85, 81% females, age = 34.6 ± 9.4 years, 62.3% unmedicated), remitted MDD (rMDD, n = 82, 80% females, age = 32.0 ± 10.2 years, 81% unmedicated) as well as healthy controls (HC, n = 136, 68% females, age = 30.6 ± 9.3 years), all born after the introduction of the measles vaccine in 1963. Logistic regression analyses controlling for age and sex showed that both the dMDD group (OR = 2.07, p = 0.026) and the rMDD group (OR = 1.98, p = 0.040) had reduced seropositivity to measles compared to HC. There were no significant relationships between age of depression onset or self-reported number of depressive episodes and measles seropositivity. All dMDD and rMDD subjects reported onset of depression subsequent to the recommended ages for MMR vaccination in the USA (12–15 months with second dose at 4–6 years). This study suggests that adults with a depressive disorder may not be fully protected from measles, and more generally raises the possibility that adolescent or adult-onset depression may reduce the ability of the immune system to maintain the long-term antibody protection normally conveyed by vaccination in childhood.