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Wednesday, February 5, 2014

Inflammation and Your Mood: A 2-Way Street

Because I'm a nerd, I receive automated updates from Pubmed, a major database of medical and psychological research, to let me know when a study has been published that contains certain keywords.  This past week I received a message about a new study published in the journal Progress in Neuro-Psychopharmacology and Biological Psychiatry (there's one for your coffee table) titled Inflamed Moods:  A Review of the Interactions Between Inflammation and Mood Disorders.

As the title of the journal might suggest, the content of the article was a bit....thick; but nevertheless reports on some really interesting findings for those who live with chronic inflammatory conditions, such as IBD, RA, or lupus.

Highlights:  The relationship between mood and inflammation in the body is a 2-way street, and was first recognized in 1887 by Julius Wagner-Jauregg of the University of Vienna, Austria who won the Nobel Prize for his work in 1927. Since then, several research studies have confirmed this relationship between our moods and the levels of inflammation in our bodies, including the parts of the immune system that might be playing a role.  Not everyone is susceptible to the inflammation-mood cycle, and there are some things you can do to help lessen the effects.

We know that inflammation is a natural response in the body, and its presence can be appropriate - like when we stub our toe or have strep throat, or inappropriate - like when our body overreacts or reacts to the wrong stimuli, like in the case of autoimmune diseases.  Regardless of if inflammation is appropriate or inappropriate, it can have negative effects on our bodies.  Anyone living with a chronic inflammatory disease can list the negative effects they experience because of the chronic "inappropriate" inflammation party going on in their body.

Inflammation is directly tied to our immune system and the various chemicals it uses to ward off threats to our well-being.  One example of these chemicals is histamine, which is released when we have an allergic reaction to something, like being stung by a bee or, in my case, having a cat lay on my face.  Common over-the-counter medications like Benadryl are anti-histamines, and do what they sound like they should:  reduce histamine in the body, thus reducing allergy symptoms.  There are several other inflammation markers in our bodies, things like IL-6 and TNF-alpha, and when these chemicals are elevated people not only report inflammation symptoms, but changes in their mood, concentration, sleep, and motivation as well.

One way we know about this relationship between mood and inflammation is from people with Hepatitis C, a chronic disease of the liver that's treated with several medications including one called Interferon.  Patients taking interferon, which boosts various parts of the immune system to fight off the Hepatitis C virus, report depression symptoms and 25% to 80% (depending on the dose of interferon) will develop major depressive disorder during their Hepatitis C treatment.  I can attest to the effects of interferon from the clients I've seen with Hep C, all of whom went on an antidepressant as part of their standard care to offset the mood side effects.

I mentioned mood and inflammation run on a 2-way street - what the authors of this study call a positive feedback loop between stress/mood and inflammation.  Researchers have also found that increased psychological, emotional, or physical stress leads to increases in these inflammation markers in the body.  Like I tell all my clients, stress isn't good for any chronic condition and for those with inflammatory conditions, it may lead to a flare-up, or worsening, of symptoms.

So how do these inflammatory substances affect mood?  You may have heard that certain chemicals in the brain, like serotonin (the second S in SSRI medications) affect our moods.  Serotonin production is reduced when certain inflammatory markers are present, and decreased serotonin leads to feelings of sadness, irritability, trouble sleeping, and other symptoms commonly seen with depression.  In addition to reducing levels of serotonin, chronically present inflammatory chemicals in the body can cause damage to healthy pathways in the brain and nervous system, or even destroy them.  Of course, those structures in the brain implicated in mood are often affected (such as the ventricles, mesolimbic pathways, and subgenual cingluate).

Why on Earth would our bodies be wired this way?  It kind of goes against the theory of "survival of the fittest," right?  One researcher, Dr. Hart, posits that this reaction is, in fact, adaptive if we were living in our "wild state" rather in our current modern society. The mood changes that occur, and other symptoms like fatigue, loss of appetite, lethargy, increased sleep, decreased interest in activities and exploration, and decreased sexual activity allow us to devote our time and energy to healing and protection from future attacks. We also are less likely to go out into the herd and share the communicable disease that's bringing us down.  Makes sense, right?  For an acute illness like the flu, we want people to stay home and if feeling down will help with that, great!  But when a chronic illness is present, the effects on mood create entirely different issues, including making the disease's symptoms worse.

Does this mean that everyone with a chronic inflammatory disease, like RA, IBD, or Lupus, also has major depressive disorder (or any other mood disorder)?  Not at all.  There are definitely variations in how a person's mood is affected by inflammation.  The authors of the paper use the term "resilience" to explain this.  Unfortunately, we don't really understand why one person may be more resilient to the effects of inflammation on mood than another.  But we do know of a few things you can do to up your resilience:
  • Aerobic exercise has been consistently shown to improve mood, and part of this may be its anti-inflammatory effects on several substances known to wreck your mood.
  • Certain foods can also help buffer the inflammation-mood cycle.  Omega-3 fatty acids have the most evidence to support their effectiveness.  Other evidence, albeit small, suggests that a "healthy" diet low in calories, fat, and carbohydrates can be protective as well (more research is needed here).
  • Being overweight can decrease your resilience to the inflammation-mood cycle, so maintain a healthy weight.
So, if you're living with a chronic inflammatory condition and you've noticed that you're mood isn't quite right, the inflammation-mood cycle may shed some light on this.  Obviously this is a complex subject, and many things play a role in our daily mood.  But do know that the underlying inflammation in your body may make you more susceptible to feeling down, irritable, or having trouble sleeping at night.  It can even lead to full-on depression.  If you're concerned about how your disease is affecting your mood, talk to your doctor about options, including if therapy might be helpful.

Dr. T.