There have been many clinical trials designed by both the pharmaceutical industry and academics in an attempt to prevent the development of dementia. However, there are many challenges associated with these clinical trials.

The pharmaceutical industry focuses on developing drugs that can stop the buildup of amyloid B peptide in the brain, as this buildup is associated with cognitive impairment. However, most trials were not successful, and these trials also require participation from individuals with pre-clinical illness, which is difficult to discover. Academic trials tend to focus on interventions that target multiple modifiable environmental factors such as blood pressure, lifestyle factors, diet and weight.

Unfortunately, it is difficult to design trials long enough to be able to successfully modify the effects of these risk factors, making it difficult to show how effective these trials are. These challenges should therefore all be considered when designing further preventative trials.