Oral and mental health are integral to overall health and well-being. Primary dentition caries is associated with poorer oral and general health and faster aging by midlife, but it remains unclear whether these associations also hold for mental health.
Objectives: To investigate whether primary dentition caries, caries experienced in adolescence and adulthood, and caries trajectories across the life course are associated with mental disorders in the fifth decade of life in two New Zealand birth cohorts.
Methods: Data on childhood caries and adult mental disorders were obtained from the Dunedin Multidisciplinary Health and Development Study and the Christchurch Health and Development Study. Generalized Linear Models (GLMs) were used to estimate associations between caries at age 5 and mental disorders at age 45/40 for Dunedin and Christchurch studies, respectively. Additional analyses using Dunedin Study data investigated associations between permanent dentition caries trajectories from ages 9 to 45 and mental disorders at age 45. All analyses adjusted for sex, perinatal health, childhood SES, childhood IQ, and adult personality.
Results: Primary dentition caries experience was not associated with mental disorders in midlife in either cohort. Dunedin Study participants who were in a less favorable permanent dentition caries trajectory had higher rates of mental disorders at age 45 than those in the low-caries trajectory.
Conclusions: People who experience poor oral health across the life course are also those who suffer from poorer mental health in mid-adulthood. A lifelong trajectory of poorer dental health indicates poorer mental health and well-being in adult life.
Keywords: cohort studies; dental caries; dental public health; epidemiology; mental disorders; oral health; public health.
© 2025 The Author(s). Journal of Public Health Dentistry published by Wiley Periodicals LLC on behalf of American Association of Public Health Dentistry.