Causes of Depression: Nature vs. Nurture, Neurotransmitters vs. Inflammation

Depression is a mood disorder that manifests as constant feelings of sadness, worthlessness, and anxiety that lasts for more than two weeks. It is one of the most common mood disorders in the world, effecting more than 264 million people worldwide. However, the cause of depression is a multi-faceted problem, oft debated amongst researchers.

Nature vs. Nuture Debate

One of the reasons why the cause of depression is often debated is because it can be either a biological or environmental cause. Environmental or “nurture” causes include:

Trauma and life circumstances. If you have experienced trauma, it can change how your brain responds to stressful situations. Your brain may triggered to a flight or fight response, or you may have overwhelming and constant worries that cause anxiety and depression. If you have experienced divorce, death or loss, that can also trigger depression episodes.
Substance abuse. Having a history of drug or alcohol abuse can trigger depression, with 21% of those who have had substance problems also experiencing depression.

Biological or physiological (“nature”) causes include:

Our genetics play a huge role in whether an individual develops depression—we are more likely to develop depression if it runs in the family.
Changes in hormones can affect how we feel, and ultimately bring about depression-like states. Circumstances like menopause and childbirth can all bring about depression.
Medical issues. If you have chronic pain, sleep issues or even attention-deficit disorder, you are more likely to develop depression.

Brain Chemistry vs. Inflammation

In addition to the nature vs. nature debate, researchers have also been digging deeper into the biological cause of depression, namely whether depression is caused by inflammation, brain chemistry, or both.

Brain chemistry. Depression is associated with how our pituitary gland and hypothalamus change our brain’s hormonal makeup. Neurotransmitters—the hormones developed by our brains—are chemical messengers that are thought to be mood-regulators, as well. Some research shows that an imbalance of neurotransmitters can cause depression-like symptoms.
There is some research to indicate that inflammation and depression are closely linked. For example, inflammation is elevated in those who suffer from depression vs. those who are not. A study of twins showed that the twin who had a higher measure of inflammation was more likely to develop depression in the future.

So, what’s the takeaway from all of this information? That there is still a lot we don’t know about depression and other psychiatric disorders. What we do know is that depression can be debilitating…and hard to treat. Talk therapy and medications fail for about 60% of patients. Fortunately, ketamine infusions have become widely available and offer hope to those with stubborn cases of depression. Up to 70% of patients experience relief after their initial series of ketamine infusions, with symptomatic relief becoming noticeable after 1-2 infusions.

If you are feeling depressed, we can help evaluate which depression treatment will work best for you, so you can start living a new life. Contact us today.