I was surprised this week to come across a paper in a medical journal which investigated the possibility that stress causes autoimmune disease. As regular readers and viewers of my film will know, I’ve been banging on about this for years.

Thirteen years ago I was diagnosed with lupus, an autoimmune disease that means my immune system attacks my own body. In recent years my doctor has changed the diagnosis to Sjogren’s disease, but whatever you call it, there’s no doubt that when I’m going through periods of unmanaged high-stress, I experience crippling fatigue and agonising arthritic pain throughout my body.

Until now, the medical conversation around diseases like mine has focussed on how symptoms are aggravated by stress rather than how the disease itself could be caused by stress. But the study I found this week signals a change. It was the first ever longitudinal study examining whether trauma exposure and post-traumatic stress disorder (PTSD) are associated with increased risk of lupus.

Over a 24-year period, researchers tracked the records of almost 55,000 women in the US and found that PTSD was associated with a nearly threefold increase in risk of subsequently developing lupus. The researchers said their data supported the now “growing evidence that psychosocial trauma and associated stress responses may lead to autoimmune disease.”

So, after reading the study I enthusiastically sat down to write this week’s blog about the mounting case that chronic stress is one of the causes of chronic disease. I was going to write about the work of Sheldon Cohen and his classic studies which showed that stressed-out people who are exposed to the flu virus are more likely to get sick than their not-so-stressed compatriots. Then I was going to highlight how scientists are starting to explore the finer mechanisms to explain this link; how some think for example that over time your immune cells start to become insensitive to the regulatory effect of the stress hormone cortisol. Essentially, the brakes on your stress response get worn through and a runaway train of inflammation can promote the development diseases.

All this was to build my argument that we need to shift the conversation from stress as being a symptom-driver and start talking about stress as being a disease-cause. But, as any good journalist should, I also began to write a caveat because although there are many studies linking stress to a whole host of difference chronic diseases, this isn’t true all the time, such as in this recent study which showed neither acute nor chronic stress influenced the likelihood that a woman with a strong family history of breast cancer would develop the disease.

It was at that point in my case-building process that I realised why my doctors have always been hesitant to blame my disease on stress. A divorced woman’s eczema flares, a bereaved man suffers a heart attack, a student develops tummy troubles at exam time. In our minds these circumstances are connected and can all be explained away by “stress.” But when you put real-life under the microscope, the connection isn’t so straight forward. Sure eczema is associated with stress, but air pollutants and cosmetic ingredients are also a trigger. It’s true that more heart attacks occur on a Monday at the start of a stressful work week, but it’s also true that people with heart disease also tend to eat a Standard American Diet (known as “SAD”) which is high in refined grains, added sugars, trans-fats and processed meats. Indeed, my own autoimmune disease has a long list of known triggers including crystalline silica, cigarette smoking, and use of oral contraceptives.

So with all that said, I can understand why doctors and other health specialists are hesitant to say that stress causes disease.

As I write these words I’m symptom free and don’t require medication for my illness. But my point is this – as I wrote in my recent piece When Old Habits Die Hard: The Science Of Being Healthy, when I’m stressed-out and time-poor, I eat junk, I sleep badly and I stop exercising. My self-control goes offline and I forget about my healthy goals and start relying on preprogrammed habits, which often aren’t the good ones.

Whether or not the chronic stress I was experiencing all those years ago when I first got sick was the cause of my disease is not (and may never be) clear. But when it comes to my health today, there’s one thing I know for sure – learning to manage my chronic stress was the crucial first step I needed to take in learning to manage my chronic illness and that’s the conversation that needs to be had between patients and their doctors from day one.