SummaryBackgroundBreastfeeding has clear short-term benefits, but its long-term consequences on human capital are yet to be established. We aimed to assess whether breastfeeding duration was associated with intelligence quotient (IQ), years of schooling, and income at the age of 30 years, in a setting where no strong social patterning of breastfeeding exists.MethodsA prospective, population-based birth cohort study of neonates was launched in 1982 in Pelotas, Brazil. Information about breastfeeding was recorded in early childhood. At 30 years of age, we studied the IQ (Wechsler Adult Intelligence Scale, 3rd version), educational attainment, and income of the participants. For the analyses, we used multiple linear regression with adjustment for ten confounding variables and the G-formula.FindingsFrom June 4, 2012, to Feb 28, 2013, of the 5914 neonates enrolled, information about IQ and breastfeeding duration was available for 3493 participants. In the crude and adjusted analyses, the durations of total breastfeeding and predominant breastfeeding (breastfeeding as the main form of nutrition with some other foods) were positively associated with IQ, educational attainment, and income. We identified dose-response associations with breastfeeding duration for IQ and educational attainment. In the confounder-adjusted analysis, participants who were breastfed for 12 months or more had higher IQ scores (difference of 3·76 points, 95% CI 2·20–5·33), more years of education (0·91 years, 0·42–1·40), and higher monthly incomes (341·0 Brazilian reals, 93·8–588·3) than did those who were breastfed for less than 1 month. The results of our mediation analysis suggested that IQ was responsible for 72% of the effect on income.InterpretationBreastfeeding is associated with improved performance in intelligence tests 30 years later, and might have an important effect in real life, by increasing educational attainment and income in adulthood.FundingWellcome Trust, International Development Research Center (Canada), CNPq, FAPERGS, and the Brazilian Ministry of Health.

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BackgroundThere is no consensus on the effects that low birth weight, premature birth and intrauterine growth have on later depression.AimsTo review systematically the evidence on the relationship of low birth weight, smallness for gestational age (SGA) and premature birth with adult depression.MethodWe searched the literature for original studies assessing the effect of low birth weight, premature birth and SGA on adult depression. Separate meta-analyses were carried out for each exposure using random and fixed effects models. We evaluated the contribution of methodological covariates to heterogeneity using meta-regression.ResultsWe identified 14 studies evaluating low birth weight, 9 premature birth and 4 SGA. Low birth weight increased the odds of depression (OR = 1.39, 95% CI 1.21–1.60). Premature birth and SGA were not associated with depression, but publication bias might have underestimated the effect of the former and only four studies evaluated SGA.ConclusionsLow birth weight was associated with depression. Future studies evaluating premature birth and SGA are needed.

The mother's poverty level, psychiatric history, partner absence and stressful life events should be considered important risk factors for relevant postpartum depressive symptoms.

Objective: To describe the prevalence of bullying victims, the characteristics of those victims and their associated symptoms in the domains of emotion, behavior, hyperactivity and peer relationships.Methods: This was a cross-sectional study nested in a cohort that assesses disorders of reading, writing and arithmetic in 1,075 students enrolled in the first to eighth grades of two public schools in a lower-middle-class neighborhood of the city of Pelotas, RS, Brazil. The KIDSCAPE questionnaire was used to evaluate the prevalence of bullying and the Strengths and Difficulties Questionnaire was used to assess victims' behavioral characteristics. Results:The prevalence of bullying was 17.6%. The most prevalent type of intimidation was verbal, followed by physical, emotional, racial and sexual. After adjustment for confounding factors, bullying was still associated with male sex (PR 1.49 95%CI 1.14-1.96), hyperactivity (PR 1.89 95%CI 1.25-2.87) and peer relationship problems (PR 1.85 95%CI 1.24-2.76). Among the victims of bullying, 47.1% had also initiated bullying. Conclusions:This study has identified the behavioral characteristics of bullying victims which may prove useful for local policies designed to protect the targets of bullying.