A research group from the National Center of Neurology and Psychiatry and Hamamatsu University School of Medicine has revealed that maternal psychological stress during the perinatal period may cause a decrease in the fetal blood zinc level, resulting in an increase in IL-6 (interleukin-6), which may be involved in the onset of childhood ADHD (attention deficit hyperactivity disorder) symptoms.
Previous studies have shown that untreated children with ADHD have elevated levels of the inflammatory cytokine IL-6 in their blood, and zinc deficiency, which is involved in immune regulation and brain function development, promotes IL-6 expression. However, there has been little research into the genetic and biological mechanisms linking zinc with ADHD or inflammatory markers.
The research group conducted a longitudinal analysis of birth cohort data, blood marker analysis, and genomic analysis using international collaborative data. The results suggested that high maternal perinatal stress (EPDS score) was associated with decreased zinc and increased IL-6 levels at birth. These IL-6 levels at birth were associated with the severity of ADHD symptoms at age 8-9 years.
They also found a genetic correlation between ADHD and blood zinc levels. Furthermore, they found a bidirectional causal relationship: genetic factors related to blood zinc levels affect the risk of developing ADHD, and genetic factors related to the onset of ADHD affect blood zinc levels. They also found that genetic variations that predispose to low blood zinc levels increase the severity of ADHD symptoms, and that genetic variations associated with the onset of ADHD predispose to low blood zinc levels.
The results of this research suggest that perinatal mental health support and nutritional approaches, including zinc supplementation, may lead to a reduction in the risk of developing neurodevelopmental disorders.
Article Information: [npj Mental Health Research] Maternal stress, cord blood zinc and attention deficit hyperactivity disorder
