Reuben A, et al. - In this multidecade, longitudinal study, researchers examined the association of childhood lead exposure with greater psychopathology across the life course and challenging adult personality attributes.

Methods

• This prospective cohort study was based on a population-representative birth cohort of individuals born between April 1, 1972, and March 31, 1973, in Dunedin, New Zealand, the Dunedin Multidisciplinary Health and Development Study.
• Members were followed up at 38 years of age in December 2012.
• The investigators performed data analysis from March 14, 2018, to October 24, 2018.
• They calculated childhood lead exposure from assessing the blood lead levels at 11 years of age.
• Blood lead levels were not related to family socioeconomic status.
• Primary outcomes included adult mental health disorder symptoms, estimated through clinical interview at 18, 21, 26, 32, and 38 years of age and transformed through confirmatory factor analysis into continuous measures of general psychopathology and internalizing, externalizing, and thought disorder symptoms and adult personality evaluated through informant report using the Big Five Personality Inventory at 26, 32, and 38 years of ages.

Results

• They tested 579 individuals (among 1037 original study members) for lead exposure at 11 years of age.
• The mean (SD) blood lead level was 11.08 (4.96) μg/dL.
• Each 5-μg/dL increase in childhood blood lead level was noted in association with an increment of 1.34-point in general psychopathology, driven by internalizing and thought disorder symptoms, after adjusting for study covariates.
• They also observed a relationship of every 5-μg/dL increase in childhood blood lead level with a 0.10-SD increase in neuroticism, a 0.09-SD decrease in agreeableness, and a 0.14-SD decrease in conscientiousness.
• They found no statistically significant associations with informant-rated extraversion and openness to experience.