Leonard Syme on Psychosocial Risk

[ed. Len Syme is Professor of Public Health at the Univ. of California Berkeley School of Public Health and a pioneer in studies of psychosocial influences on health. This essay is abstracted from his interview with Darwin Labarthe in 2003.]

I’m becoming a little bored with all of this population health and stuff because to me it’s old hat. I think we need to move on to the next challenges. To me the next major challenges are going to have to be to figure out how social factors get ‘into the body’ to cause disease. McKuen at Rockefeller University comes up with a concept called alostatic load. It’s basically a reworking of the bodily consequences of stress . . . You remember Selye talked about a generalized adaptation syndrome?

The alostatic load is an updated version of that, that takes account of the fact that the body’s equilibrium mechanism changes over time. But the trouble with it is it’s really a laundry list of immunological responses. It’s not thoughtful or theoretically based. It’s just a bunch of stuff you know how to do. You know, [measuring] C-reactive proteins. So you make a list and while it’s not very thoughtful I think it’s a major step forward that other people are now going to pursue and eventually we are going to get a better handle on how it is that this stuff changes bodily function.

You see, when I told you that established heart disease risk factors account for less than half of heart disease that occurs, my answer to that problem is two-fold. Number one, I think the research we’ve been doing in population health has shown that the psychosocial factors act most importantly by influencing the body’s vulnerability — people getting sick by changing the immune function— not introducing this or that disease. I think what disease you get is a function of the specific risk factors you have — the cholesterols, the blood pressures, the viruses [and genetic susceptibility?]. So that would explain why the psycho-social factors are related not just to this disease but to a lot of diseases and why the risk factors we know [to be] important are not critically correlated with disease occurrence. This is an idea that John Cassel talked about in the ’76 paper. None of this is new, but I think it’s becoming more clearly understood. So we really have to begin to understand the body’s psycho-neural-immunology or the socio-psycho-neuro-immunology of the situation.

The problem is, if you keep looking at one disease at a time, the only things you will learn about are the things related to that disease. And that has really limited our ability to develop trends, transcending concepts, that will really help us understand population health. You see, when we talk about population health I think a lot of what we’re doing is more or less individually based on risk factors and disease and we need to make the next step. We’re not going to be able to do it until we have a better outcome variable than one disease at a time.

For example, if we were able to understand the impact of social connection on an immune response, I think we would then be able to talk about population concepts independent of disease and talk about population concepts and how they affect vulnerability. Complicated stuff. But to me, you know, the whole multi-level business is now becoming a mechanism where we begin to understand the impact of the social and individual levels. Much of the new research in population health is really beginning to look at major factors.

For example, here’s a problem in a population. Suppose you wanted to do a study on the health consequences of poverty. What institute at NIH would you send it to? Or what if you wanted to study health consequences of discrimination, or nutritional deficiency diseases, or inappropriate sexual behavior? They would send it to an institute of one or another disease focus. But by doing that you make it impossible to see the significance of these concepts. So, I think we’re at a turning point in our work. In fact, I think that’s what the next major challenges will be. So that’s moving away from heart disease now.

[ ed. A National Institute of Population Health is needed to study things like social class that are apparently profound determinants of health. We need to understand what that’s about and be able to intervene appropriately.]

It would be very nice to characterize what we mean by general susceptibility. Even now, if I did a session with you and I looked at stuff, I could probably get 15 or 20 markers of how things are going. What Institute would fund that? This is a profound handicap. But to me, that’s why I was mentioning that the new view is going to have to be to try and link these things to how these factors get into the body so we can really begin to develop a better understanding of these social factors. Right now, social class is a meaningless word. That doesn’t help us at all. Income is a marker and it helps us to begin our research. But we need to go way beyond that, and I don’t know how we’re going to do it unless we have a better lever than outcome variables, because if we keep looking at cancer and heart disease and arthritis we’re not going to make it.

Reference

Syme, Leonard in an interview recorded by Darwin Labarthe August 21, 2003. History of Cardiovascular Epidemiology Archive, University of Minnesota.