<human>: Can you provide a brief rundown of the text in within 3 sentences?

The father of one of my friends died recently, and my family was talking about it at dinner tonight. He apparently died of a heart attack, and everyone is still in shock about it. As we were talking, my mom said that she thought that "people choose to die" (direct quote). I thought she might have meant that people choose to do things (eat certain foods, live certain lifestyles, ect) that shorten their lives, but I was still sort of confused, so I asked her to explain. 

Let me say that while my whole family is not religious, my mom believes in the whole ["The Secret"] bullshit. She thinks that thinking about good things will cause more good things to happen. I agree with this to the extent that focusing good things makes you notice them more, thus giving the illusion that they happen more often, but she believes that thinking about certain things actually has a physical impact on the world. Conversely, she believes that focusing on bad things will attract more bad things to you. 

Following this logic, she concluded that people who die of disease bring it upon themselves by thinking too negatively. She literally thinks that people can give themselves cancer, alzheimers, and other terminal illnesses by focusing too much on bad stuff and just being generally pessimistic. 

Needless to say, I found this to be extremely offensive. When I told her that I knew of people who were always optimistic and nice who had died far too early from diseases like cancer ([example] she said that they must have been sad on the inside, and were merely hiding it. I found this to be even more offensive than her previous statement, and I started arguing with her about how the placebo effect doesn't work like that (she thought it was plausible that a perfectly healthy person could give themselves cancer if you told them that they had it) and other things, but she refused to see reason and held steadfastly to her previous position.
<bot>: read the title. Citing studies and other hard facts would be much appreciated, because despite believing in the pile of hogwash that is "The Secret", she kept on asking me for proof.