Cognitive Impairment as a Mediator in the Developmental Pathway From Infant Malnutrition to Adolescent Depressive Symptoms in Barbadian Youth

Objective: Depressive symptoms are elevated in adolescents who experienced significant malnutrition early in life. Early malnutrition can also have a significant impact on cognitive functioning, presumably because of the adverse impact of the malnutrition on the very young brain. In the context of a developmental cascade model, we tested the hypothesis that the association between early malnutrition and adolescent depressive symptoms is mediated by the cognitive impairment that ensues from the malnutrition. Methods: We evaluated Barbadian youth (N = 57) hospitalized for moderate to severe protein-energy malnutrition in the first year of life and healthy controls (N = 60) longitudinally. The primary hypothesis was tested by multiple regression models. Results: After adjusting for covariates, early malnutrition predicted both cognitive functioning in childhood (IQ, p < .001; attention problems, p < .01; Common Entrance Examination, p < .01; and adolescent depressive symptoms, p < .05). Childhood cognitive functioning mediated the association between early malnutrition and depressive symptoms in adolescence (p < .001). Maternal depressive symptoms were a significant but independent predictor of adolescent depressive symptoms (p < .05). Conclusions: Cognitive compromise in childhood accounts indirectly for elevated depressive symptoms in previously malnourished adolescents, consistent with a developmental cascade model. The direct link between malnutrition and depressive symptoms in adolescence is small. (J Dev Behav Pediatr 32:225-232, 2011)