The interactive model

So to illustrate the findings that we reported in the paper, in the journal Plos One, we’ve constructed this little Excel spreadsheet. What we’ve got is an equation that represents the output from the structural equation model that relates biological problems, social problems, and life events through the mediating effects of rumination to lead to mental health problems. And the very simple, in statistical terms, equation that’s included here, represents both direct and mediated effects of these different causal issues. What this allows us to do, what this Excel spreadsheet allows us to do, is to play with the different variables to see how they impact on our mental health.

So we can imagine a baseline position of maybe 50%, for want of a better word, threat in each of the areas and how that impacts on our mental health. If we then increase the degree of threats to a person’s mental health by changing these figures from say 50% to 75%, we can see how it changes the levels of their mental health problems. So increase in their biological vulnerability from 50% to 75% has a noticeable effect on the person’s mental health. If we return the biological score back to 50%, do the same with social problems, increasing that to 75%, again, you can see an impact on the mental health.

Impact on a mental health of changing level of social disability, in this equation, has a very slightly smaller impact than effect in their biological problem simply because the equation has slightly different figures in there. If we return that to 50% and look at the impact of an increase in the number of negative life events on a person’s problems, you’ll see a more significant impact on their mental health. What really makes a difference, however, is if we look at the changes in somebody’s tendency to ruminate. Again, if we make the same numerical change from 50% to 75% in their level of rumination, you can see a very marked impact on their mental health.

Of course, in the real world, you’re likely to have increased levels of life events, increased levels of social problems, and the tendency to ruminate as that pushes up the person’s mental health scores quite considerably.

This is not intended to be direct research. The numbers 50%, 75% are just illustrations. Obviously, biological problems and social problems in life events don’t come in neat percentages. It allows you to play around with the numbers and to show how both the input variables of the actual problems themselves, biological, social, and life events and the mediating effects of rumination impact on our mental health. To help you look at this in a little bit more detail, we’ve included the Excel spreadsheet on the course website, so you can download it and play around with the numbers yourself. You can also, incidentally, check that I’ve got the equation right, which might be an important of the process.

We’ve made this spreadsheet available in a format that you can access on the course website with instructions for how to do the manipulation of the variables I’ve just illustrated, and of course, to check that I’ve got the equation right.