There's more money to be made from researching into baldness than curing cancer or dementia. That funding is from government and charity sources combined.

(Long term treatments of course is another thing - that's why we have expensive daily tablets for malaria, but no vaccine. More profitable to charge $1/day than charge $50 for a one-off vaccine)

Pfizer have pulled out of neuroscience research completely, Saracatinib (from AstraZeneca) was a failed cancer drug before someone thought "hey lets try this on dementia"