Objective: To reduce the risk of bronchopulmonary dysplasia, preterm infants receive neonatal treatment with glucocorticoids, mostly dexamethasone (DEX). Compared to current protocols, treatment regimens of the late 1980s - early 1990s prescribed high doses of DEX for an extensive period up to 6 weeks. Worldwide at least one million children have been treated with this dose regimen. Previous studies have shown adverse effects of neonatal treatment with the glucocorticoid dexamethasone (DEX) on outcome in children aged 7-10 years. On the other hand, treatment with another glucocorticoid, hydrocortisone (HC), was not related to adverse effects in childhood. In the current study we determined the consequences of early life intervention with DEX or HC in adolescents (age 14-17 years). Besides motor function and intellectual capacities, we also examined fundamental neuropsychological functions which have so far received little attention. Methods: In an observational cohort study we compared 14-17 year-old adolescents who received DEX (.5. mg/kg/day tapering off to .1. mg/kg/day over 21 days, n=. 63), or HC (5. mg/kg/day tapering off to 1. mg/kg/day over 22 days, n=. 67), or did not receive neonatal glucocorticoids (untreated, n=. 71) after premature birth (gestational age.