**3. Results**

We found three main results. First, maternal depression was detrimental to a child's vocabulary at the age of 5, but the effect faded out by age 8. Our estimations indicated that 1 standard

deviation of maternal depression during pregnancy and postpartum reduced the vocabulary of 5-year-old children—measured through PPTV scores—in 0.54 standard deviations. This impact is no longer statistically significant at the age of 8, even considering different measures of maternal depression. The magnitude of these effects is large and consistent with the upper bound found in the existing literature.

Second, heterogeneity analysis by household wealth shows that these effects were driven by children living in disadvantaged households. When the impact of maternal depression was analyzed separately by household wealth, there was evidence of worse effects for less wealthy households, providing suggestive evidence that maternal mental illness may contribute to the intergenerational transmission of poverty given the high rates of depression among low-income mothers cited in the literature.

Finally, we explored if the presence of household members that supported mothers can dampen the effect of experiencing a shock that affects maternal mental health. We focused on the presence of a partner in the household when the woman was pregnant or during the first year after childbirth. Our estimations indicated that mental health issues of women living with a partner when they experienced a shock effect more their child's vocabulary than those without a partner. Upon further exploration, we found that women living with heavy-drinking partners were the ones driving the negative impacts on the child's cognitive development. In this sense, this set of results indicates that it is not the presence of a partner in itself that matters, but the quality of such partners.
