That was actually my first thought. The link talks about 70% decrease of Alzheimer risk over a 6 year period of Viagra use (vs lack thereof). But early Alzhei

That was actually my first thought. The link talks about 70% decrease of Alzheimer risk over a 6 year period of Viagra use (vs lack thereof). But early Alzheimer signs have been shown to appear up to 18 years before diagnosis. Memory and thinking tests for these signs from 13 to 18 years before diagnosis show 85% higher risk in those failing. [0] So 6 years is actually a very short window to claim causality, especially when it can be guessed through other means with (my guess) higher accuracy. [0] https://www.alzheimers.org.uk/research/care-and-cure-research-magazine/signs-dementia-seen-18-years-diagnosis https://www.alzheimers.org.uk/research/care-and-cure-researc...