A Life Course Study of Early Childhood Height Growth and Adult Working Memory and Depression Outcomes

Evidence has been mounting that exposures during fetal development and early postnatal life are important determinants of many adult health outcomes including. diabetes, obesity and cardiovascular disease. Critical periods of early development have been identified for certain outcomes. Early life factors are suspected as having a role in cognitive and psychiatric outcomes, but research to date is limited. Birth weight, considered a marker for fetal development, has been positively associated with cognitive abilities. A few postnatal studies provide evidence that early childhood height growth, an indicator of overall development, is also positively associated with cognitive abilities in adults under age 25 years. There has been no research on early childhood height growth and cognitive outcomes in middle age adults. Low birth weight has also been associated with a spectrum of neuropsychiatric disorders, including, in one study, affective disorders. There are no known studies of early childhood height growth and neuropsychiatric disorders. With this background, I made two hypotheses. First, I hypothesized that early childhood height growth is positively associated with working memory ability in middle age adults. Second, I hypothesized that early childhood height growth is inversely associated with lifetime major depressive disorder in middle age adults. I also explored effect modification by sex and by small for gestational age status. I tested these hypotheses using data from the Early Determinants of Adult Health (EDAH) study and its sister study Fetal Antecedents of Major Depression and Cardiovascular Disease (MDCVD). These studies were adult follow-up studies of two birth cohorts recruited in the 1960’s: the Child Health and Development Studies (CHDS) and the New England Family Study (NEFS); both followed subjects from birth through childhood. Birth length and successive early childhood height measures were available enabling a study of three height growth periods, birth to 4 months, 4 months to 1 year and 1 to 4 years. The adult follow up study included 4 measures of different aspects of working memory ability as well as a structured interview that assessed neuropsychiatric outcomes including lifetime major depressive disorder. We found some evidence that early childhood height growth was positively associated with adult working memory ability in specific growth periods. Results of the analysis of early childhood height growth and adult lifetime MDD do not support the association between early childhood height growth and lifetime MDD.