Dementia starts out seemingly as forgetfulness, but moves to serious brain degeneration.
There is no cure, but research has come a long way, with new drugs on trial suggesting new treatments may be coming closer. For most, part brain plaque is considered to be the cause.
Now researchers in Australia have used ultrasound to remove plaque from the brains of mice - and have seen improvements in memory - while other research is focusing on the role of immune cells in that build-up of plaque.
Biotech company Biogen has seen its market capitalisation soar by $40bn since December 2014 when it announced its experimental drug for Alzheimer's slowed progression of the disease.
Unfortunately these successes are the exceptions rather than the rule. There have been 101 failed attempts at producing drugs for dementia between 1998 and 2012. Over the same period there were just three successful ones.
The number of people with dementia will reach $135m by the year 2050, with care costs in the US alone to exceed $1tn.
|Dementia Infographic [Al Jazeera]
So, is there hope for a cure or effective treatment? And how will the world pay for the increasing burden on healthcare as the number of sufferers increases?
Melissa Stevens is from a biomedical research action tank called "Faster Cures", which aims to speed the whole process up and get to a cure faster. She talks to Counting the Cost.
Source: Al Jazeera