OBJECTIVES On 5 November 2015, the Fundão tailings dam collapsed causing the biggest environmental disaster caused by the mining industry in Brazil. According to Minas Gerais General Government report, 1,039,797 people were directly affected. In the “Research on Mental Health Reality in Mariana” (PRISMMA study), prevalence of depression, generalized anxiety disorder (GAD) and post-traumatic stress disorder (PTSD) (28.9%, 32% and 12%, respectively) found are higher than those in the literature for general population. This study aims to evaluate the economic burden related to mental health management of individuals affected by the Marina's disaster.

METHODS Epidemiological data collected from PRISMMA by NAVeS-UFMG was applied to demographic information from Minas Gerais State related to the disaster. For the budget impact, eligible population was calculated as the difference between prevalence for general population and the prevalence found after the disaster for depression, GAD and PTSD. Resource utilization and microcosting were retrieved from public databases associated to expert opinion. Costs are presented in 2018 Brazilian Real (BRL), from the Brazilian public healthcare system perspective.

RESULTS After the disaster 240,193 new cases of depression, 236,033 GAD and 114,377 PTSD were estimated. Direct costs per person-year for depression, GAD and PTSD were 420.15BRL, 457.06BRL, and 403.85BRL, respectively. If all patients with mental health disturbance after the tragedy were diagnosed and treated, annual budget impact would represent 254,988,939.98BRL. Even if only half patients were treated, a budget impact of more than 120 million BRL was estimated from the Brazilian public perspective or 2.2% of the credit authorized to be spent on health by Minas Gerais State.

CONCLUSIONS In addition to tangible and intangible costs related to the environment and health, the burden of Mariana's tragedy on mental health represented a major budgetary impact. Further real-world studies on mental health with long-term follow-up are necessary to assess overall results of this disaster.