Humanitarian crises affect over 200 million people globally and exact a large toll on population mental health. We assessed the impact of an economic transfer program on the mental health of internally displaced persons and host populations in eastern Democratic Republic of Congo (DRC).

We conducted a randomised trial among vulnerable households residing in 25 villages in North Kivu Province, DRC, where a large United Nations program responds to population displacement by providing economic transfers in the form of vouchers for essential household items (EHI). Households that were in need of assistance but outside the program’s standard eligibility criteria were randomly assigned (1:1) to a “voucher” or to “no intervention”. Households in the voucher group received US$50-92 worth of vouchers to use at a fair where EHI, such as blankets, clothes, buckets, and pans, were sold. The head woman of each household was interviewed just before the fair, six weeks and one year after the fair. The primary outcomes were standardized indices of adult’s mental health, children’s physical health, social cohesion, and resilience. Effects were assessed in least-squares regression models adjusting for baseline levels. 

Between August 2017 and March 2018, we enrolled 976 households in the study. 488 were randomly assigned to the EHI voucher and 488 to no intervention. 88% of respondents were female. At baseline, 33% of respondents had an anxiety/depression score suggesting clinical significance. At six weeks, the voucher group had a 0.32 standard deviation units (SDU) improvement on the mental health index (95% CI 0.18 to 0.46), and, after one year, the voucher group had a 0.19 SDU improvement (95% CI 0.02 to 0.34). There were no effects on the child health, social cohesion, or resilience indices.