While there are so many great news/drug about AD treatment..There is also something called "Publication bias & self-censoring". A pervasive bias is non-reporting of negative results. This is almost impossible to prevent. Journals dont publish every article that is submitted to them: they prefer to publish articles that find something. A good place to start is a paper by Ioannidis (2005) with the depressing title Why most published research findings are false.