Could depression be triggered by our immune system?

The Guardian has recently reported on growing support from scientists that depression could be a result of inflammation caused by the body’s immune system.

As much to do with the body as with the mind?

George Slavich, a clinical psychologist at the University of California in Los Angeles, who has studied depression for many years firmly believes it has as much to do with the body as it has with the mind. He says “I don’t even talk about it as a psychiatric condition any more. It does involve psychology, but it also involves equal parts of biology and physical health.”  

Behaviour when sick looks a lot like depression

Psychologists have already coined the term ‘sickness behaviour’ seen in those suffering from an illness – feelings of misery, tiredness, boredom and apathy. They’re actually there for a good reason, probably to stop us making the illness worse or spreading it to others. Sickness behaviour looks very much like depression therefore it’s not implausible that there may be a common cause for both.

Inflammation the most likely candidate

The most likely candidate for the common cause so far is inflammation in the body. Inflammation is part of the immune system function, it calls other part of the immune system in the body to action to deal with injury and illness. Specifically it is a group of proteins called cytokines that kicks off inflammation in the body and flicks the brain into sickness mode.

Research looks to support claim

Research conducted on sufferers of bipolar depression has shown both cytokines and inflammation to increase sharply during depressive episodes and decrease again during periods of remission. Further studies have shown that temporary depression and anxiety can be induced in healthy people by administering a vaccine that causes a spike in inflammation. Other clues include: people with inflammatory diseases such as rheumatoid arthritis tend to suffer more than average with depression and cancer patients given an inflammatory response boosting drug called interferon alpha often suffer from depression as a side effect. Obesity is another risk factor as body fat, particularly around the belly, stores large quantities of cytokines.

Stress also a factor

Stress also causes inflammation, especially that resulting from social rejection or loneliness – characteristics of modern life that could explain why prevalence of depression has increased so much across the world.

Omega-3s and Curcumin (Turmeric) may offer natural treatment

More research is needed, however a small number of clinical trials have shown that adding anti-inflammatory medicines to antidepressants improves symptoms as well as increasing the proportion of people that respond to the treatment. Interestingly, there is also some evidence to suggest that Omega-3 and curcumin (a compound of turmeric) might have similar effects.  Both are very easy to obtain in supplement form so it might be worth considering adding to a prescribed treatment (always consult your doctor first if you are taking prescription medicines).