Honestly, I think you're reading too much in to this. If someone close to me ended up committing suicide and I wanted to hide it, I could come up with a much more direct and believable cause of death than Alzheimers/pneumonia especially for someone under 55. Simply saying he died of a heart attack would do it.

I would not be surprised if the hush hush part is due to the Alzheimers. Mental illness (even though Alzheimers is not really defined as a mental illness) has a stigma attached, still. Especially at such a young age. I'm watching my second older friend go through it (the first one passed away at the age of 77), and it's absolutely heartbreaking. My friend now is 83 and has lived a wonderful life, but her husband, who is the sweetest guy I know, is 86 and fit as a fiddle (goes to the gym daily) and he's bewildered and lost with her going through this. I could not imagine how horrible it would be to see someone in his prime lose himself in this way. Maybe she just cannot bare to be reminded right now.