The last 25 years have seen discouraging failures of our attempts to slow cognitive and functional decline in Alzheimer's disease, despite good evidence that some treatments have engaged with amyloid or tau associated pathology. It now seems unlikely that any of the agents currently under trial are going to prove to be clinically effective, although some may be licensed on the basis of selective data analysis, minute patient-level benefits and general desperation within the field for a treatment. 
Some in the field have suggested that this is the time for a "Dementia Moonshot", in terms of investment and coordinated effort to overcome the failures. I would argue that putting a man on the Moon took more than 65 years from the Wright brothers' first successful powered escape from our planet's surface and a number of important discoveries and developments along the way. Neuroscience is always moving forward and it is hard to predict when an individual basic discovery that unlocks a potentially effective therapy will occur. In the meantime, perseverating with the current failing paradigm for disease modification research does not appear efficient. 
Although symptomatic treatments may not have the glamour of disease modifiers, we do have agents that can modestly improve cognition and function in dementia and repurposed drugs that offer benefits in the treatment of agitation and psychosis. But we have a long way to go before we can achieve the symptomatic treatment successes seen, for example, in Parkinson's disease. I would argue that, if we want to see developments in treatment that will realistically offer benefits to people with dementia over the next 10 years, we will have to focus research on symptomatic drug treatments and other "Care" interventions. 

THIS LECTURE IS PRESENTED BY THE FRANK AND DEBBI SOBEY LECTURESHIP IN ALZHEIMER'S