RESUMEN
ABSTRACT BACKGROUND: Psychosocial care centers for alcohol and drug users (CAPS-ad) are reference services for treatment of drug users within the Brazilian National Health System. Knowledge of their total costs within the evidence-based decision-making process for public-resource allocation is essential. The aims here were to estimate the total costs of a CAPS-ad and the costs of packages of care (according to intensity of care); to ascertain the ratio between total CAPS-ad costs and the federal funding allocated; and to describe the methods for estimating unit costs for each CAPS-ad cost component. DESIGN AND SETTING: Retrospective study conducted in a public community mental health service. METHODS: This was a retrospective cost description study on a CAPS-ad located in a city in the state of São Paulo, using a public healthcare provider perspective and a top-down approach, conducted over a 180-day period from March 1 to August 30, 2015. RESULTS: The total mean monthly costs of the CAPS-ad were BRL 64,017.54. Healthcare staff accounted for 56.5% of total costs. The mean costs per capita and per month for intensive and non-intensive care packages were, respectively, BRL 668.34 and BRL 37.12. CONCLUSIONS: The federal budget allocation covered 62.1% of the CAPS-ad costs and the remaining 37.9% end up funded by the municipal government. The cost of the intensive package of care was 18 times greater than the non-intensive package. Developing criteria for using services and different packages of care based on patients' needs, and optimizing human resources according to specific actions, may improve people's mental health and avoid wasted resources.