Childhood adversity is responsible for up to one-third of all mental health disorders, researchers say.
There aren’t many tools available for doctors to identify children who may face mental health issues later in life. But a new study shows baby teeth may offer some missing clues.
Like trees, baby teeth have growth lines that can vary in size depending on the environment and experiences of their parent while pregnant and shortly after birth. Physical stress, including poor nutrition or disease, can influence the development of teeth’s outer shell, or enamel, in a way that thickens growth lines.
Using a microscope, researchers with Massachusetts General Hospital analyzed 70 donated baby teeth that fell from the mouths of 70 children when they were between ages 5 and 7. They studied a specific kind of growth line called a neonatal line.
The team found children whose parents had histories of severe depression or other mental health problems and those who were depressed or anxious at 32 weeks of pregnancy had teeth with thicker neonatal lines than other kids.
Children with parents who were socially supported shortly after pregnancy were more likely to have teeth with thinner neonatal lines, suggesting thicker lines indicate more stressful life experiences.
Childhood adversity is responsible for up to one-third of all mental health disorders, according to the study published Nov. 9 in the journal Psychiatry.
Researchers say their findings could aid the development of official biomarkers of early stressful conditions that could help guide children toward preventive treatments for mental health issues before they arise or become serious.
The lack of such tools is holding doctors back from properly measuring childhood exposure to stressful conditions. Asking parents about painful experiences can lead to “poor recall or reluctance,” giving health care professionals little to work with to help guide patient care.
“[If] we can connect those kids to interventions … we can prevent the onset of mental health disorders, and do that as early on in the lifespan as we possibly can,” senior study author Erin Dunn, a social and psychiatric epidemiologist with Massachusetts General Hospital, said in a news release.
The reason these neonatal lines grow is still a bit mysterious, Dunn said, but researchers speculate parents’ production of the stress hormone called cortisol may interfere with cells that produce enamel, which in turn affect the development of growth lines.
Inflammation in the body could also explain the thickened growth lines in children of stressed parents, but larger studies are needed to better understand the process.
Children included in the study were enrolled in the Avon Longitudinal Study of Parents and Children in the U.K. between 1991 and 1998. The teeth were analyzed between 2019 to 2021.
Parents completed questionnaires about stressful events during pregnancy, history of mental health issues, the quality of their neighborhood and the level of social support they received — all factors that contribute to childhood development.