Depression is not a result of a "chemical imbalance" - Baobab Health

Depression is not a result of a “chemical imbalance”

In my last post around this topic, I discussed how anti-depressants have been shown to be now more effective than placebo in treating depression and why they are not an effective treatment for depression.

Anti-depressants increase certain neurotransmitters (e.g. seretonin) in the brain, as it was once thought that depression resulted from a “chemical imbalance” of these neurotransmitters. However,  the “chemical imbalance” theory of depression is not grounded in much evidence, which is probably why anti-depressants have been shown to be no more effective than placebo in treating depression.

This post will challenge the “chemical imbalance” theory of depression, which will help you understand the reasons as to why anti-depressants lack efficacy in treating all cases of depression.

Depression is unlikely to be caused by a chemical imbalance in the brain.

It is so ingrained into our psyche (which is probably due to the media and the selling of anti-depressants) that depression results from a “chemical imbalance” in our brain and anti-depressants aim to correct this imbalance. The simplicity of the chemical imbalance theory may be a convenient way to sell drugs, however the similarity of anti-depressants to placebo, certainly casts doubt on this theory.

This is because we have taken a multi faceted disease, which involves a complex interaction between genetic, diet, lifestyle, environmental and social factors and narrowed it down to the imbalance of a couple of neurotransmitters (chemicals) in the brain and developed drugs to increase these neurotransmitters.

Furthermore, there are certain things that we know about neurotransmitters and how they function, which has further casted doubt on the chemical imbalance theory.

For example, we know that 100 or more neurotransmitters have been identified in the pathology of depression and some patients may have low seretonin but others don’t. Some have increased amounts. Cocaine and meth both increase serotonin and norepinephrine but don’t decrease depression. Also, some drugs don’t affect serotonin and norepinephrine however they help with depression. And lastly, anti-depressants take a few weeks to effect your mood however changes in neurotransmitter balance are seen very soon after drug administration.

Obviously these factors cast doubt on the chemical imbalance theory of depression, however at the end of the day it is far easier and cheaper for a health care system to characterise depression as a physical disease due to a simple chemical imbalance, prescribe a drug and send someone on their way. Meanwhile, it is a lot harder and costly to address the social and environmental aspects that contribute to the disease. We fail to remember that our emotions effect our physiology and our physiology effects our emotions.

So if a chemical imbalance does not cause depression, then what does?

Well, there is no one single cause of depression. As I mentioned in the last post, it is a multi-faceted disease that has many different causes and effects people in very different ways.

However, new evidence is emerging that depression, on a physiological basis is an inflammatory disease and there is a lot of evidence to support this. For example:

  1. When healthy patients are injected with LPS (inflammatory molecule produced from bacteria) they display depressive symptoms.
  2. An anti-viral drug used to treat hepatitis called interferon causes significant inflammation in the body and one of its potential adverse reactions is depression.
  3. People with depression usually have heightened inflammatory markers such as CRP and IL-6.

So where does the inflammation come from? Well, the current theory is that this inflammation originates in our guts, which is caused by a  dysfunction of the gut-brain axis.

Our guts are filled with millions of bacterial species and research is starting to reveal how crucial these gut bacteria are to our overall health. An imbalance of good and bad bacteria in our gut is starting to be implicated as a driving factor behind many chronic diseases, including depression.

In depression, it is thought that an overgrowth of “bad” bacteria in the gut causes a condition called small intestinal bacterial overgrowth (SIBO), which I have written about here. SIBO increases the production of inflammatory messengers in the gut, which enter the blood stream, travel to the brain and then activate inflammatory pathways in the brain. Inflammation in the brain can potentially cause depression in those who are predisposed.

It is well established in the scientific literature that there is a strong link between the microbes in our gut and signalling in our brain. This connection is called the gut-brain axis link. The gut-brain axis explains the correlation between IBS (irritable bowel syndrome) and depression. Especially because IBS is closely associated with SIBO and SIBO is associated with depression.

This gut-brain link also provides an explanation as to why probiotic and prebiotic supplementation has been shown to help with depressive symptoms. It also explains why some people can get depression without any significant life circumstances (e.g. poverty, unemployment, negative life situations, life altering events) that would warrant a person to get depressed.

This is because we know that poor diet and lifestyle factors such as a diet high in processed and refined foods, excess alcohol, smoking, long term psychological stress, chronic lack of sleep and a lack of exercise all contribute to bacterial overgrowth through various mechanisms.

Our diet and lifestyle choices effect our physiology and then our physiology effects our emotions, mood, cognition and behavior. Also, once depression occurs, individuals diet and lifestyle choices also tend to get worse.

Furthermore, independent of the gut-brain axis link, depression can certainly be a result of stressful life circumstances as we know stress can have inflammatory and disrupting effects on the brain, which can cause depression in the predisposed. It must also be noted that stress is not only psychological. Poor diet and lifestyle habits are also a form of physical stress.

In today’s modern world we are more stressed than ever, which is probably a huge contributing factor to the rise in depression.

We live high stress, fast paced lifestyles, where we are working more than ever and having less fun. There are also many aspects of our modern culture that create an environment conducive to depression. For example, we are told to try to attain happiness from external things (rather than within ourselves) or become a certain way that our society/others makes us believe we should aspire to. This leads us to live unfulfilling lives, without a lot of purpose and authenticity. A lack of purpose in life is a huge contributing factor to depression.

Another example is that there is an extreme pressure to “succeed” and be “above average.” This leads us to derive a lot of our self-esteem from being “more successful” than others and causes us to compare ourselves to others. This is a huge disservice to our being as we should try to be the best forms of ourselves.

Increased technology usage causes a culture of social exclusion and decreased face-to-face human connection. The lack of sense of community that we have can really effect us, which may be a reason as to why people in the third world have lower rates of depression. People in the third world have a much greater sense of community and social connection, which is clearly evident in the amount of street socialisation that occurs daily.

I think if we recognise that depression goes far deeper than a few neurotransmitters in the brain, then we can address the underlying causes of this disease and put preventative measures in place, leading to better and more long term therapeutic outcomes.

Using drugs that are no more effective than placebo, with harmful side effects may create dependency and numb our senses, preventing growth and self-change in order to get out of a lifestyle cycle that is causing/contributing to depression.

Treating depression should take a holistic approach by addressing the underlying causes of the depression, which are outlined in this review.

Wrap up.

I want to make it clear that this article was not written to criticise doctors.

We cannot be angry at our health practitioners for prescribing anti-depressants as they are going by what they have been taught. There is no doubt that many doctors refer their patients to psychologists and may even recommend lifestyle changes to patients. However, patients are still usually put on anti-depressants, which I believe should be re-thought due to the existing evidence on these drugs. I am merely advocating for a paradigm shift as depression is reaching epidemic levels and I feel like our current treatment of it is proving ineffectual.

If you suffer from depression or know someone who does, the first step would be to find a good health care practitioner that is aware of the current research and is willing to work with you to change various environmental, cognitive and lifestyle habits that may be the underlying causes to your depression.

Also, they may be able to help introduce certain drug free treatments that have been shown to be helpful in treating depression such as:

  • Psychotherapy
  • Cognitive based therapy
  • Meditation and yoga
  • Animal therapy
  • Nature therapy
  • Exercise 
  • Improving sleeping quality and quantity
  • Light therapy
  • Healthy diet changes
  • Supplementation with zinc, vitamin D, curcumin (tumeric extract), st. johns wart, fish oils and SAM e have also been shown to be helpful, as well as many other nutritional and herbal supplements.

Due to the lack of strong evidence for anti-depressants and the side effects, I believe these options should be explored first in depression treatment. Anti-depressants should be seen as a last resort, while trying to integrate the above treatments. Furthermore, even if someone is on anti-depressants, these treatments should still be addressed.