Perinatal depression, which affects 20-30% women in low-income countries, is a known risk factor for impaired child development. The purpose of the current project is to examine whether participating in a successful perinatal depression intervention (Thinking Healthy Programme, THP) has lead to improved developmental outcomes in the offspring. The THP was delivered in Pakistan in 2006; in 2012 the children will be 5-6 years old and entering kindergarten, thus allowing for an assessment of a wide range of cognitive, socio-emotional, motor and physical developmental outcomes. The THP was a clustered randomized trial where lay Lady Health Workers (LHWs) were trained to deliver a cognitive behavior therapy (CBT) intervention to mothers with major depression. In the intervention group, the health workers' routine practice of maternal and child health education incorporated CBT techniques (active listening, collaboration with the family, guided discovery of alternative health beliefs and the assigning of homework to apply what had been learned). A total of 463 mothers received the intervention and 440 received enhanced routine care which consisted of an equal number of LHW visits. At 6 months post partum, 77% of mothers in the intervention group recovered from their depressive disorder compared to and 47% in the control group, effects which were sustained at 12 months. Parents in the intervention group reported spending more time everyday on play-related activities. The main approach of the THP follow-up study consists of re-enrolling the original THP study participants and assessing developmental outcomes in the now 5-6 year old children, together with potential mediators and moderators of any association between the intervention and the outcomes of interest. We are locating and interviewing the LHWs who participated in the original study to better understand factors influencing the sustainable implementation of the intervention in the field. We are using a multi-pronged approach to re-enroll study participants. Because the original intervention was community-based, we have detailed information on the residence location of all study participants. Importantly, the Lady Health Worker infrastructure in the study area is a significant strength. The LHWs are village-based and cover about a hundred house-holds in their village. They maintain careful records of each mother and child under their care. Our re-enrollment strategies thus include direct contact based on original study residence with inquiries of family and neighbors if the woman no longer lives there; inquiring with the original cohort and current LHWs about the location of remaining women; and checking local hospital and administrative records to confirm deaths or relocations. With these strategies, we plan to successfully re-enroll 80-90% of original THP study participants. The specific domains that are assessing include child cognitive skills, executive functioning, socio-emotional skills and social functioning, motor skills, school readiness as well as anthropometric and overall health indicators. We also propose to collect detailed data on factors that may shed light on the pathways and moderators that influence the magnitude of impact of the intervention on the child outcomes 5 years later. These include the level of environmental social and cognitive stimulation in the home, mental health of other family members including the mother, socioeconomic status, as well as community factors such as access to education. If the study demonstrates a positive impact of the intervention on the child outcomes, it will provide a major impetus to policy-makers and health-planners to address maternal depression in early child development strategies.