In addition to the research cash, a global investment fund will be launched to get private, public and philanthropic backing for efforts to discover new treatements and eventually a cure.
The Prime Minister’s Challenge on Dementia 2020 includes plans to help three million volunteers, including staff at companies such as M&S and Argos, become “dementia friends” who know how to support those with the condition.
Every one of the 1.3 million people employed by the NHS from surgeons to hospital porters will be trained in dementia care.
Mr Cameron is also pledging that the average wait for a dementia assessment be reduced to six weeks. At the moment some patients have to wait up to six months.
The Prime Minister said: “Dementia is one of the greatest challenges of our lifetime, and I am proud that we are leading the world in fighting it.
“Because of the growing strength of our economy, we can invest in research and drug-development, as well as public understanding, so we defeat this terrible condition and offer more hope and dignity for those who suffer.
“That way, we can help make Britain a country that offers security in retirement for all.”
Today’s announcement is the latest intervention on dementia from the Prime Minister who last year described the condition as “one of the greatest enemies of humanity” as he called for global action.
Experts in the field estimate that within the next ten years more than one million people in the UK will be living with dementia.