When it comes to our emotions, we know there are a lot of factors at play. But have you ever wondered about how our immune systems and mood are connected? Although it might seem like our physical and mental health are entirely separate — and of course it's possible either to be in great physical health but struggling emotionally, or to be battling a physical illness and have a solid, healthy mental state — research supports the fact that the two do affect each other. This extends to our moods, and luckily for us, researchers have been exploring this connection quite a bit, and what they've found sheds light on how we can improve both our physical health and our mental health — because sometimes, working on one might help the other, too.
It's important to remember that when it comes to research, scientists are typically digging into very specific angles of particular topics, so one study or finding doesn't necessarily speak for all cases. That said, studies can be super illuminating when it comes to correlations and possible causation (although of course, correlation doesn't necessarily equal causation). For instance, understanding how immune systems and moods relate to one another can be helpful in better understanding people's mental or physical health when they experience certain issues, such as depression or even immune system disorders that can be life-long. Better understanding the possible relationships between symptoms may make it easier to find the right approach to treatment and healing.
The studies below are certainly not all-inclusive, but they're great starting point for checking out some of the most common correlations between our immune systems and our moods. And as always, if you have any questions or concerns, definitely talk to a medical professional ASAP.
1. Negative Emotions Make It Harder For Your Immune System To Fight Off Illness
Researchers from the University of Wisconsin-Madison recently discovered that brain activity may show the link between negative emotions and a reduced immune system for fighting off diseases. Study leader, Richard Davidson, and his colleagues, tested 52 men and women by asking them to write down their most intense sadness or fear, then measured the electrical activity of their brains. Subjects were then given flu shots and returned to the lab to have their antibody levels measured at two weeks, four weeks and six months.
While researchers in this study couldn't find a correlation specifically between happiness and the immune system, there was a clear connection in brain activity between those who experienced negative emotions and a weaker immune system via strong activity in the left PFC and a significant rise in antibodies. The researchers are still searching for an exact explanation, but as they explained to New Scientist, there is "evidence to suggest a link between the PFC and the immune system via a complex hormonal system governed by the hypothalamic, pituitary and adrenal glands."
2. Happiness May Boost Your Immune System
On the flip side of the previous point, Steve Cole, researcher and professor at the Cousins Center for Psychoneuroimmunology at the University of California, Los Angeles, discovered that there may be a link between happiness and a boost in your immune system. Cole and his team of researchers look at broad patterns of gene expressions through transcriptional analysis to see connections between emotions (negative and positive) and immune systems. According to Scientific American, Cole and his team discovered that "people with a meaning-based or purpose-based outlook had favorable gene-expression profiles, whereas hedonic well-being, when it occurred on its own, was associated with profiles similar to those seen in individuals facing adversity."
In layperson's terms, Cole's research suggests that negative mental states, such as when are you feeling lonely or depressed, can actually have an impact on our gene expression, which in turn impacts our immune system's response. His research suggests that positive mental states may have the same affect by essentially building a healthier response in our genes and sending that to our immune system.
3. Stress Can Make You More Susceptible To Illness
Most of us have probably experienced first hand the way that stress can negatively impact our immune systems. As Andrew Goliszek Ph.D explains over at Psychology Today, "Ongoing stress makes us susceptible to illness and disease because the brain sends defense signals to the endocrine system, which then releases an array of hormones that not only gets us ready for emergency situations but severely depresses our immunity at the same time." When our immune systems are depressed, we have a harder time fighting off diseases. Because stress can build over time and become an ongoing, chronic issue, Goliszek stresses the importance of stress management and coping skills on the day-to-day basis.
4. Depression May Hurt Your Immune System
Psychologist Janice Kiecolt-Glaser, Ph.D, is the co-author of a study on the ways depression may hurt your immune system. The study, done at Ohio State University, discovered that there is an exaggerated inflammatory response to immune challenges. Researchers tested 47 people who were already feeling stressed and suffering subclinical depression. After a single flu shot, the stressed and depressed subjects had an overproduction of the immune system component interleukin-6, one of the markers of long-term inflammation. Notably, these subjects were not diagnosed with depression, but instead had moderate symptoms of it, such as difficulty sleeping and low moods.
All in all, it's so important to keep track not only of changes in your body, but also of changes in your mood. Knowing when symptoms arise or changes occur may help you realize what the culprit is behind shifts in your emotional and mental state. The opposite may be true, as well, in that keeping track of what physical ailments arise during sad, stressful times may reveal the cause of your struggles.