Women living in low- and middle-income countries are more exposed to known risk factors for depression occurrence and persistency over time. Our aim was to investigate the course of depression in the first 2 years postpartum among Brazilian women enrolled in a cash transfer program. Longitudinal analysis of baseline (T0; mean 3.7 months postpartum) and first follow-up data (T1; mean 18.6 months postpartum) from a trial to assess the impact of a child development promotion program in 30 municipalities from six Brazilian states. The program does not include any interventions against maternal depression. The Edinburgh Postnatal Depression Scale (EPDS) at cutoff ⩾10 was applied. Women were categorized into four groups based on EPDS at T0 and T1: absence of depression, persistence, discontinuity, or emergence pattern. Adjusted Poisson regressions were run using a multilevel hierarchical model. Two thousand eight hundred sixty-three women were assessed. Prevalence of depression was 26.4% [24.8, 28.1] at T0 and 24.4% [22.8, 26.0] at T1. Persistence, discontinuation, and emergence were found in 14.1% [11.3, 17.6%], 12.8% [11.4, 14.3%], and 10.2% [8.0, 13.0], respectively. In adjusted analyses, the persistence pattern was directly associated with parity and inversely associated with schooling of the woman and of the child's father. Living with husband/partner and support from the child's father and family members during pregnancy were protective against persistence. The discontinuity and the emergence patterns were not associated with any of the exposure variables. Depressive symptoms were highly prevalent during the first 2 years postpartum. About half of the women with depression at T1 were persistent cases that could have been detected earlier. Screening for maternal depression should be an essential component in every encounter of women with health professionals in primary health care settings.