Depression: The Science of the Incompetent Postman

KF- Writer and Content Editor

Depression is a word that has skyrocketed into familiarity over the last decade. While this widespread issue can take many forms in different people and is slowly, ever so cautiously starting to gather the recognition it deserves, there are still plenty of misconceptions about depression. 

I often hear it said (particularly by the older generation) that such things simply did not exist back in the golden age of their memories. These people often say similar things about autism or dyslexia, speaking with an edge of suspicion as though these conditions simply manifested into existence the day the first millennial was born. To this argument, I find myself frequently reminding that we also used to believe that certain children were ‘born sickly’- whatever that catch-all term is supposed to mean? 

It wasn’t for centuries later that we became aware of congenital heart conditions, growth malformations in utero or the plethora of other things we are now able to study, label, understand and ultimately treat. We can now look back at the annals of history and say hey maybe it wasn’t such a great idea to inbreed our nobility all that time? 

Further still we need only look back at the scores of famous artistic souls who led notoriously tortured lives, often meeting cruelly premature ends at their own hands, to know that this is not a brand-new issue. We can clearly see depression (sometimes coupled with other mental illnesses) throughout social history and today, we are starting to scratch the surface of diseases such as depression in terms of science. 

So, what do we know about depression today? 

We know that it can cause feelings of intense hopelessness, elevated feelings of guilt, indecisiveness, lack of motivation, irritability, tearfulness, altered appetite, altered sleeping patterns, a completely numb void of emotion… the list goes on and on, culminating in suicidal thoughts and behaviours. 

A person who is depressed can experience the full spectrum of these symptoms or just a few, be they the most intense or those that are difficult to notice. When it comes to depression, the way it manifests is different to some degree within every single person, with enough crossover to allow us to identify it, but enough differences that it can be difficult to spot. 

How does it come about?

Well, it can be triggered by many different things. A traumatic event such as a bereavement, assault or a job loss can trigger depression even in someone who has never previously experienced it. This is the category that post-natal depression falls into after a person experiences the trauma of birth, although it is more specific and differentiated from the wider net of ‘depression’. 

Existing personality traits can lead some people to be more at risk of developing depression, especially if they suffer from low self-esteem and lack of confidence. Unsurprisingly, this risk can be exacerbated by issues such as bullying, toxic relationships or hostile working environments which chip away at victims’ feelings of self-worth. It should come as no shock that kicking someone when they’re down doesn’t pave the way to recovery. 

Seasonal depression (also known as seasonal affective disorder) is directly related to the seasons (no prizes for that guess). This affects a lot more people than may realise it, as winter months darken and become colder many people develop seasonal depression, finding it much harder to find motivation, think positively or commit to self-care. This is one reason that many people put on weight over the winter months as food is often used as a coping mechanism during periods of emotional distress.

Research has also been carried out to find a hereditary link (suggesting that depression can be passed genetically through families like many other diseases), and one study has isolated a gene passed in families believed to be linked to higher risk of depression (although further studies are needed to replicate this). 

There is mounting evidence to suggest that a predisposition towards depression runs in families, although the likelihood of it developing also depends on a range of environmental factors such as the quality of home life. A loving, supportive family who build confidence and high self-esteem in their children can lessen the risk of those children developing depression. Although that’s not to say bad parenting will guarantee depression or that good parenting will always prevent it, there’s a lot more to it than that. 

Some people are affected by depression for only a single period of their lives and manage to recover, never experiencing it again. This is most likely in cases of depression brought on by a traumatic event, the damage of which is lessened over time or through therapy. However, some people experience episodic or constant depression throughout their entire lives for no clear, obvious reason to the unknowing onlooker. When this is the case, it is known as clinical depression or major depressive disorder and it is important to remember that depression is an illness, not a bad mood response. 

One word that is often associated with depression is: serotonin. Serotonin (chemically known as 5-HT) is a neurotransmitter produced mostly in the brain and bowels and stored in blood platelets. Neurotransmitters are essentially the postmen of the nervous system, sending messages to all our cells so they know what to do and how to respond to different things. 

Serotonin is responsible for stabilising our moods, regulating sleep patterns, nearly all human behaviours and a plethora of other bodily functions. As a mood regulator, it is easy to see why people have drawn a link between levels of serotonin and depression. When the postman who delivers the cells’ instructions for happiness and contentment isn’t turning up, it’s bound to cause problems. 

This idea backs up the genetic link theory, as it is possible that a genetic problem with serotonin production (postman shortage) or reception (letterbox is locked) could be passed on hereditarily. This means that some people may be born unable to produce or utilise enough of the chemical that allows you to balance your mood, leading to the skyrocketing highs followed by prolonged, crushing lows often associated with depression. 

Although studies have produced conflicting evidence about the role of serotonin in relation to depression, serotonin treatment in tablet form has proved to be successful in treating thousands of people suffering from depression. Interestingly, 95% of the body’s serotonin is found in the gut, and studies have found strong links between serotonin levels and irritable bowel syndrome (IBS). 

Since serotonin cannot cross the brain-blood barrier (the bouncer on the door to the central nervous system’s super special fluid), the brain must make its own supply of serotonin, unable to access the gut’s supply. Therefore, the drugs used to treat depression do not add serotonin to the body but trigger the reactions in the brain needed to produce it.

There is a long way to go before we fully understand depression as an illness, its causes and the full variety of ways it can manifest itself. Hopefully a better understanding of the science behind it and less stigma around the subject can help more people to understand that their friend isn’t simply moody or exaggerating, their postman just isn’t turning up. 

References 

https://ajp.psychiatryonline.org/doi/full/10.1176/appi.ajp.2011.10091342

https://www.sciencedirect.com/science/article/abs/pii/S001650850602436X

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5864293/#R8

https://www.medicalnewstoday.com/articles/232248#definition

https://www.healthline.com/health/depression/genetic