As one of my specialist areas is psychoneuroimmunology, I want to highlight some interesting research that I’ve been aware of for some time, that takes a new and intriguing view of depression, one that views depression from an immunological point of view.
As any therapist knows, depression can be a devastating illness, plaguing millions of people worldwide with feelings of sadness, hopelessness, apathy and fatigue. The pharmacy industry has made an absolute fortune out of creating drugs that are used to treat the condition. But despite numerous antidepressants being produced, different classes of antidepressants being created, different doses being tried out, as many as a third of patients with depression don’t respond to medication at all. Why this may be the case has remained a conundrum, one that has forced doctors and researchers to step outside the box, as it were, and be more creative in exploring different treatment options for patients, and to revisit the underlying theories that try to explain what depression is.
Researchers have increasingly been focussing on a seemingly unrelated condition, one that has traditionally fallen into the realm of immunology: inflammation. We all know that inflammation can stem from injury or infection. After all, it’s part of our bodies healing response that brings white blood cells and other elements of the immune system to where they are needed. We call it inflammation because the affected area becomes red as blood flows there. What we now know is that emotional issues such as an unhappy relationship or problems at work can result in tissues within our body becoming inflamed. Not to the same extent as when they are injured, but inflamed all the same. It is helpful to remember that some amount of inflammation is generally beneficial to us, as it ramps up production of cytokines – proteins found in our immune system that play a major role in healing and protecting us.
But remember: too much of a good thing can lead to harm! Research has found that excessive levels of cytokines, and the inflammation they bring on, could come at an emotional cost. There are an increasing number of studies that suggest that high levels of cytokines could be a contributing factor in depression. On top of this, some studies are also indicating that anti-inflammatory drugs could potentially be used to reduce cytokine levels and possibly help people recover from depression.
But we need to make sure we aren’t jumping the gun too soon. As promising as anti-inflammatory drug administration might seem to be for depression, using them as a treatment isn’t as straight forward as we could hope. Studies have indicated that only 20 to 30 percent of people with depression have demonstrably high levels of inflammation. Where there is treatment-resistant depression, it’s 45 percent showing high inflammation levels. We need to remember, however, that as yet no clinical treatment guidelines exist to identify who these patients are and what levels of anti-inflammatory medication they may need.
And there is, of course, the question of whether treating depressed patients with low levels of inflammation would be beneficial or detrimental.
This research also brings into question the concept of what depression is. Is it one particular condition, or is the word ‘depression’ a cover-all for a group of different conditions, the characteristics of which are only just being discovered.
Peter Mabbutt FBSCH
Here are two reviews exploring the role of cytokines in depression for those who want to read more:
Köhler O, Benros ME, Nordentoft M, Farkouh ME, Iyengar RL, Mors O and Krogh J (2014) Effect of anti-inflammatory treatment on depression, depressive symptoms, and adverse effects: a systematic review and meta-analysis of randomized clinical trials JAMA Psychiatry 71(12): 1381-1391
Mills NT, Scott JG, Wray NR, Cohen‐Woods S and Baune BT (2013) Research review: the role of cytokines in depression in adolescents: a systematic review Journal of Child Psychology and Psychiatry 54(8) 816-835