Cognitive ability and decline after early life stress exposure

Abstract

We examined the effects of early life stress on cognitive ability and decline among men of the Helsinki Birth Cohort Study, 10% of whom were separated temporarily (mean age at separation = 4.1 years) from their parent(s) during World War II. The men underwent the Finnish Defense Forces Basic Intellectual Ability Test twice, at 20 years and retest at 70 years. Compared with the men without childhood separation and matched for year of birth (n = 186), men separated from their parents (n = 93) scored lower by 5.5 (95% confidence interval [CI], -9.2 to -1.7), 4.2 (95% CI, -8.1 to -0.3), 3.1 (95% CI, -7.0 to 0.8), and 4.5 (95% CI, -10.5 to -1.4) standardized points (SD = 15) on verbal, visuospatial, arithmetic, and general cognitive ability, respectively, at 70 years. Longer duration of separation was associated with lower test scores. Though early life stress was also associated significantly with weaker cognitive performance at the ages 20 and 70 years, it was not associated with cognitive decline over the 50-year period within this sample.