Depression and the Inflamed Brain

Have you ever experienced depression? Or been close to someone who has been through it? If you’ve answered yes to either question then you don’t need me to describe the magnitude of the suffering it puts people through. Simply put, it’s like being locked into a psychological box of hell.

Recently I was surprised to learn that although depression is a leading cause of disability worldwide, there have been no major advances in drug treatments for it for over thirty years. As the only readily available NHS treatment option, antidepressants do work well for some but for others they are ineffective and can even make the symptoms worse. I remember as a teenager many years ago, under the care of the community psychiatric team, I was prescribed 3 or 4 different types of antidepressant medication before we found one that worked. And it could be argued that it worked a bit too well – triggering a lengthy and dangerous psychotic episode of mania. 

Helplessness is a pretty good watch word for depression. At its darkest, it feels like a pit you will never be able to climb out of. It overwhelms you with its power. It feels so much bigger than you are. Like an infinite force, a weight that’s pressing down on you as a solitary, helpless individual.

But perhaps depression’s seemingly immense power is more precarious than it seems. A significant volume of immuno-psychiatry research carried out over the past decade indicates that it might be, and suggests that depression is often the result of a simple biological mechanism, a mechanism we can readily intercept.

The mechanism is bodily inflammation.

A large body of research now demonstrates that bodily inflammation often precedes depression, suggesting that depressive symptoms could be a direct result of inflammation.

A 2014 study in Bristol and the south west of 15,000 children found that those who were not depressed but were slightly inflamed aged  9 were significantly more likely to be depressed as eighteen year olds. A study in Denmark of 73,131 adults found that the higher the inflammation markers in their blood, the greater the depression experienced.

Why would this be? Because inflammation in the body triggers inflammation in the brain, and inflammation in the brain can trigger the onset of depressive symptoms.

When our brains’ nerve cells (i.e. neurons) become inflamed all sorts of troublesome things kick-off which contribute to a depressed state being created:

·  supply of serotonin between neurons gets affected which creates a problem because disrupted serotonin supply plays a big role in depression, affecting mood, sleep and appetite.

·  activity increases in the emotional network areas of the brain (e.g. the amygdala and the cingulate - bad news for mood.

·  neurons shrink  back or even die.

·  the regenerative process that would help new neurons grow back gets blocked.

·  synaptic connections between the neurons go rigid, which is not good because when they are nice and plastic they function better in terms of helping us with adaptive behaviour, learning and memory.

·  neurons to start producing substances such as kynurenine which have a toxic effect on the neurons by over-exciting them, exhausting them, and eventually killing them.

So given the catastrophic damage it can wreak on our minds, we could obviously benefit from thinking about how to protect ourselves from bodily inflammation and to do that we have to consider what causes bodily inflammation in the first place.

Some of the causes of bodily inflammation are more surprising than others. Many of us already know that illness and injury can cause it, as inflammation is part of the body’s natural healing response. There are seasonal factors relating to this too – we get more inflamed in the winter months when there are more bugs about. Age increases inflammation risk, as does obesity.

Some foods promote inflammation, other foods decrease it, so diet is an obvious lever for tackling inflammation-induced depression. (Apparently rosemary is an anti-inflammatory par excellence and it tastes surprisingly all right as a tea.

Few people realise though, that high levels of social stress increase bodily inflammation to perhaps an even more significant degree than any of these other factors. It is no coincidence that people who experienced a lot of social stress as children through neglect or abuse are more likely to be inflamed (and depressed) as adults.

Social stress can be experienced at any time of life and stems from things like rejection, loneliness, conflict, loss of relationship and poverty. Some of the social stresses we endure as we move through life are avoidable. Being assertive, knowing how to manage conflict with others through active communication and pro-actively strengthening our relationships are just a few of the ways we can fend off social stress.

The sad fact is though, that there’s a lot of social stress that we can not avoid. Loss of loved ones, redundancies, abuse – these will inevitably trigger an inflammatory response in us. So the question becomes, if we can’t prevent having an inflammatory response to certain difficult situations, then how do we at least manage it and reduce it? A question that is especially relevant to survivors of childhood adversity who will often have their inflammatory response to even minor social stresses set on a hair trigger.

A direct approach we can take is to strengthen what is called the ‘inflammatory reflex’. The inflammatory reflex is a calming reflex that is mediated by the Vagus nerve, a massive nerve that stretches from our belly to our brain. When the Vagus nerve detects high levels of inflammation in the body, it sends an electric signal up to the brain, and the brain then pings a signal back down the Vagus nerve that calms the immune cells and reduces inflammation.

So in a nutshell, the Vagus nerve calms things down and by stimulating the Vagus nerve, we can strengthen its ability to do this.

Practises that studies have shown to reliably strengthen the Vagus nerve include:

·  cold showers / cold swimming

·  activated breathing exercises.

·  mind-body practises such a tai-chi,

·  meditation techniques,

·  forest-bathing

and

·  ear twiddling….

Because the outer shell-like parts of our ears is the only point on the body’s surface where the Vagus nerve is close enough to the surface to be stimulated by touch, twenty minutes of stimulation ot this area a day here causes rapid and substantial reductions to bodily inflammation according to 2019 research by Addorisio. Although his research used mild electrical stimulation there’s no reason to suggest that using your finger tips wouldn’t also have a beneficial impact.

The stress-inflammation-depression relationship is not straight-forward. It can catch us up in a vicious cycle.  For example, once we are depressed we are likely to experience even more social stress due to pressure that our depression can place on relationships, or the isolation and withdrawal it can cause, not to mention things like lost income, stigmatisation and other factors that might also come into the mix. And if we are more reactive to stress and more readily inflamed  because of early-life problems, we might inadvertently develop patterns of behaviour that cause unnecessary extra social stresses in our lives, adding to the inflammation-induced depression, deepening our difficulties.

But it might be that the simplicity of being focused on avoiding, managing and reducing bodily inflammation is what can cut through the complexity of the problem of depression, and give us a corner of our mind-body where we are not helpless in the face of emotions that can so often make us feel like we are.

If you’d like to learn more about this I recommend reading The Inflamed Mind by Ed Bullmore; an excellent book that got me onto this.