The worldwide costs of dementia were estimated at United States (US) $818 billion in 2015. This estimated worldwide costs represent an increase of 35% since 2010. Eighty-six percent of the costs occur in high-income countries. Costs of informal care and the direct costs of social care still contribute similar proportions of total costs, whereas the costs in the medical sector are much lower. The threshold of US $1 trillion will be crossed by 2018.