Very preterm adolescents show impaired performance with increasing demands in executive function tasks

Background: Very preterm birth is often associated with executive function deficits later in life. The transition to adolescence increases personal autonomy, independence and, in parallel, the demands placed on executive functions at home and in school. Aim: To assess the impact of increasing demands on executive function performance in very preterm children and adolescents with normal intellectual and motor functions. Methods: Forty-one very preterm children and adolescents with normal intellectual and motor functions and 43 healthy term-born peers were assessed at a mean age of 13.0 years (SD: 1.9; range: 10.0-16.9).A comprehensive battery of performance-based executive function measures with different demand levels as well as a parent rating questionnaire evaluating executive functions relevant for everyday life was applied. Standardized mean differences between groups of d >=.41 were regarded as clinically relevant. Results: No group differences were found at the lowest demand levels of working memory (d=.09), planning (d=.01), cognitive flexibility (d=-.21) and verbal fluency (d=.14) tasks, but very preterm participants scored significantly below their term-born peers in the most demanding levels (d=-.50,-.59,-.43 and-.55, respectively). These differences were clinically relevant. Executive functions relevant for everyday life were strongly impaired in very preterm participants, e.g., global executive composite (d=-.66). Conclusion: Very preterm children and adolescents with normal intellectual and motor functions are at high risk for executive function deficits that may only become apparent with increasing demands, potentially leading to academic and other deficits. (C) 2015 Elsevier Ireland Ltd. All rights reserved.