So now let's consider work and family and life stage. And you can see, I think, in this section that we're going to depart farther and farther away from our classic research designs, even though we retain the logic of them a little bit. We're going to be using different types of survey data to analyze and search for risk factors. And that is consistent with Jerry Morris' seventh use of epidemiology, that is, suggesting clues to etiology. Now this is what we call a color category forest plot. A forest plot is a way of putting together data from many different studies. You can see on the bottom there that x-axis is the relative risk or the odds ratio. And on the left hand side you can see one or another different studies. So there'll be, in study A, a study of a work on job overload. A study of job overload or whether the job was suitable for the individual. We wanted to put all the studies of work environment that were prospective in the cohort form and population-based onto one slide, which we were able to do. But we wanted to indicate that they were, the results were originating from different studies. So that's the reason for the different colors. So in the top there, you can see that job overload raises the risk for depression by about five. That's the little square in the middle of the red bar on top. And the ends of that bar are the 95% confidence intervals for that particular estimate. And when you see a forest plot like this and everything is over on the right hand side, you know that the results are similar across the different studies and when you see that the left hand vertical bar on a given plot is to the right of the vertical black bar you know that that's significantly different than one there 95% confidence interval does not include one. That's that black bar in the center. So what this shows is that work environment effects risk for depression. I want you to concentrate down there on the green and orange and purple bars in the middle there as something called there's a literature on strain high job strain and job strain is produced in a position in which the demand for performance is high. So this might be a worker on an assembly line in which the assembly line is going very rapidly, and the worker has to pay attention. And that might be called high psychological demand. There also might be a high psychological demand job in a normal work environment, in which demands for production that were very high. Now we have a situation of so called low decision latitude and this is the situation in which the worker regardless of demand this is independent of demand has very little ability to influence the way the work is performed so again we have the assembly worker can't really change the content of the assembly line. Or an example of this is what we used to call a secretary. She basically has very little latitude as to what the work she does. Her boss walks in, put stuff on her inbox and she has to get it out. And actually this is, sort of a an old way of thinking. But her boss, you know can shout Vivian bring me the so and so or bring the so and so file at any given time. And basically, she has no control over the flow of work And likewise, the assembly line worker may not have much control over the flow of work. So when you combine a high-demand job with a low decision job, low latitude job, that is called a high job strain position. And actually, you can envision different workers in that situation. I have read that many assembly lines in Japan have red pulleys, red halters at all the work stations. And the red halters are symbolic for the most part, but if the worker notices that something is going wrong with the assembly line, they can pull the red halter and stop the assembly line. And of course, they rarely do or never do. But the fact is, they feel like they have the ability to do so and that may change the way they think about the job. High job strain is associated with future heart attacks, as it happens. There's a strong literature on that, but in this slide we see the new disassociate with onset for depressive disorder as well. So that's lots of demand pressure and a not much influence over the way the work is conducted. So now, consider this work. This is, again, by George Brown. And you have to hold the work strain idea, the job strain, in your mind for a second. We're going to take a little detour, and come back to it. This is data from East London. It's from women in East London. And on the one hand, it studies the effect of class, lower class or middle class life on depression. And that's, the percentage with depression is on the left-hand axis. And you can see that the lower class has a slightly higher risk for depressive disorder. That's the orange bar, and then the middle class, which is the chartreuse bar at the bottom. But one of the interesting things is, which Brown discovered, is this difference between the classes is not really statistically significant, except for one part of the life stage. This is for a woman who was children less than six, or six to 14 in her home, mostly less than six. Now we're thinking well the class difference doesn't really exist except in one particular life stage in which there are children in the home. Now look at the right hand side that's the percentage with a confidant and that's the top two bars and you can see that the middle class and the lower class differ. And the percentage of people who have confidants. The middle class are more likely to have confidants. But again, it's not really different. And it's statistically not different between the middle and the lower class, except for this same life stage, children less than six. And these are women. So, now we have this situation. No confidant, lower class and children less than six, and one of the possibilities for this explanation is that that woman is in a high job strain position that is she has a child less than six. You know I just babysitted for my grandchildren. And it's a heck of a thing taking care of two kids under the age of three because you can't tell what they're going to do. And you just have to jump and do what they, and it's true, you can pick them up, that's one of the big advantages, but they are very unpredictable and they take a lot of energy. And so the idea here is that possibly we've captured the same psychological constellation, that is the work environment, which has high job strain in the lower class women. And as perhaps a, a slight confirmation of this, we have a recent publication. And the more recent than George Brown, anyway, in the American Journal of Public Health, about parenting stress. These are different collections of parenting stress. For example, T is, they've spend too much time with the child, F is, they don't have support for instrumental support, you know, functional money, and then E is a lack of emotional support, and P has had trouble paying for child care. And you can see, when you add up all these parenting stressors, they're much more likely to have a probability of poor mental health. This is not the same as depressive disorder, it's poor mental health, but I'm trying to illustrate the same possibility that the work environment for the general work environment as well as the homemaking environment has the potential to raise the risk for depressive disorder. And so that's the issue of combining work and family and life stage in a, an interaction that may raise risk for depressive disorder.
