I have problems with the study. First most of the women were not menopausal which is closer to the age of most breast cancer diagnosis.

Second it was in Isreal which is a high stress country, so these women's happiness may be different to other women's happiness in other countries. Children in Isreal are taught from day one not to pick up any thing off the street or anything that is not theirs for fear it may be a bomb. While we teach our children to look both ways when crossing the street, the end result is the same, but the critical attitude is different.

Third, I hate hearing people say that if you have a positive attitude, it will help your cancer recovery. Now I have to hear that if I was happier I would not have even had cancer!

Everyone likes to be around happy people. That includes Doctors, nurses,and researchers, but I just don't buy it from this study that the answer is happiness, judged how again?

Hi, Spaghettiodreams!

You make a great point. I can especially relate to your first one: just because we have a positive outlook on life, and always try to be happy, doesn't mean that life isn't going to throw us curveballs! Or in this case, traumatic life events. Do you have any specific examples?

Thanks, Spaghettiodreams!

Well, it's certainly no secret to the research community that there is an intricate relationship between the immune, central nervous, and endocrine systems.

This mechanism is not clearly understood, however we do know that one subset of immune cells (lymphocytes) have receptors for neuroendocrine substances, allowing all three systems to interstimulate.

This study (entire article is open access on BMC) somewhat validates that point, however, the design is flawed: a) the researchers did a poor job of distinguishing "psychological outlook" vs. "traumatic life events." Their results suggest that happiness & optimism result in decreased risks of BC, while traumatic life events result in higher levels of BC. These are two completely separate things.  In evaluating BC risk the study should have focused on either, "optimism vs. depression" or, "traumatic life events vs. no traumatic life events." b) This study did not account for the fact that BC in itself is likely to result in increased depression. Are the increased depression rates seen with the BC group really a result of their traumatic life events, or is it just because they know they are living with the disease? c) controls were not randomly selected-huge flaw. To better assess this risk, I think it'd be wise to do a life-span study-take a large group of people, follow them over the course of 10-20+ years, documenting their traumatic life events, psychological outlook, and ultimately, disease development.