Depression is one of the leading causes of disability globally, with a higher prevalence among women than men. The postpartum period may pose additional risks for women; the incidence of postpartum major depressive disorder is mildly increased compared to non-pregnant women, with postpartum depression affecting approximately 15% of women. Little is known about postpartum depression in low- and middle-income countries, although a review that included 47 studies in the pregnancy and postpartum periods showed that common mental health disorders (including depression) were present in 19.8% of women. These findings are concerning because, globally, many children will be exposed to maternal depression and postpartum depression is often considered a strong risk factor for widespread effects on children’s emotional, behavioral, cognitive, physical and neurological development. Empirical information on the long-term association between postpartum depression and child outcomes in low- and middle-income countries is scarce. Children in these countries may be at greater risk for the negative effects of postpartum depression, even at a very young age. There is a strong correlation between postpartum depression and infant malnutrition, low birth weight, and psychosocial risk that may be influenced by factors such as poor in utero environment due to famine or natural catastrophes. In the Lancet Psychiatry, Nienke Verkuijl and colleagues report on a longitudinal study conducted in South Africa that aimed to clarify the correlation between maternal symptoms of postpartum depression and children’s psychological development at age 10 years. After controlling for socioeconomic status and the mother’s current depressive status, children whose mothers had depressive symptoms at 6 months postpartum were 2 times more likely to have psychological problems at age 10 than children whose mothers were not depressed. This longitudinal correlation was particularly significant in the 1/10th of children with the most severe scores. And this longitudinal correlation disappeared once the current maternal depressive status was taken into account. To my knowledge, this study is one of only a few long-term behavioral follow-up studies of children of mothers with depressive symptoms conducted in low- and middle-income countries. However, the study, conducted by Verkuijl and colleagues, is not without its limitations. It is a challenge to maintain the participation of subjects in longitudinal studies for more than a decade, especially in susceptible patients, even when the situation is at its best. Attrition is more pronounced in low- and middle-income countries than in high-income countries because their research infrastructure may be less developed. In addition, sociocultural factors may influence attrition – such as lack of permanent residence. Attrition is a major limitation of the study. When recruitment began, there were 3,273 mother-child pairs, but only 644 pairs were available for 10-year follow-up, a retention rate of roughly 20 percent of the original sample. The authors also acknowledged this limitation and noted that this was partly due to transient migration between urban and rural areas. In addition, different methods were used to assess maternal depression, using the Pitt scale in the early postnatal period (6 months after birth) and the Center for Epidemiologic Studies Depression Scale (CES-D) used at the 10-year follow-up. The correlation between these two time points was low, although about 20% of the women scored above the cut-off values at 6 months and 10 years. Postpartum depression and child psychological problems were not recorded between these two assessment time points, which is unfortunate for the observation between postpartum depression and child psychological outcomes. We we only have a simple understanding of postnatal depression at 6 months after birth, and at the latter two time points at 10-year follow-up, but no information throughout childhood that could help us better understand the underlying mechanisms of intergenerational transfer of risk. Thus, it is difficult to conclude that the postnatal period poses specific risks to children’s psychological functioning because there is no additional knowledge about the chronicity and severity of depression over time, factors that have been shown to affect children’s prognosis in studies of populations in high-income countries. Despite these methodological shortcomings, findings from low- and middle-income countries must be given public attention and due weight. Because we know that postnatal depression is a strong risk factor for poor child prognosis, and this correlation is significant in low- and middle-income countries. Verkuijl and colleagues may have conservatively estimated the problem because of physiological and psychosocial stressors.