LONDON: For three decades, people have been deluged with information suggesting that depression is caused by a “chemical imbalance” in the brain – namely an imbalance of a brain chemical called serotonin. However, our latest research review shows that the evidence does not support it.
Although first proposed in the 1960s, the serotonin theory of depression started to be widely promoted by the pharmaceutical industry in the 1990s in association with its efforts to market a new range of antidepressants, known as selective serotonin-reuptake inhibitors or SSRIs.
The idea was also endorsed by official institutions such as the American Psychiatric Association, which still tells the public that “differences in certain chemicals in the brain may contribute to symptoms of depression”.
Countless doctors have repeated the message all over the world, in their private surgeries and in the media. People accepted what they were told. And many started taking antidepressants because they believed they had something wrong with their brain that required an antidepressant to put right.
In the period of this marketing push, antidepressant use climbed dramatically, and they are now prescribed to one in six of the adult population in England, for example.
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For a long time, certain academics, including some leading psychiatrists, have suggested that there is no satisfactory evidence to support the idea that depression is a result of abnormally low or inactive serotonin. Others continue to endorse the theory. Until now, however, there has been no comprehensive review of the research on serotonin and depression that could enable firm conclusions either way.
At first sight, the fact that SSRI-type antidepressants act on the serotonin system appears to support the serotonin theory of depression. SSRIs temporarily increase the availability of serotonin in the brain, but this does not necessarily imply that depression is caused by the opposite of this effect.
There are other explanations for antidepressants’ effects. In fact, drug trials show that antidepressants are barely distinguishable from a placebo (dummy pill) when it comes to treating depression. Also, antidepressants appear to have a generalised emotion-numbing effect which may influence people’s moods, although we do not know how this effect is produced or much about it.
World Mental Health Day: Feeling Low? Oats, Bananas, Berries & Nuts Can Keep Anxiety & Depr…
Table of contents
- 1 World Mental Health Day: Feeling Low? Oats, Bananas, Berries & Nuts Can Keep Anxiety & Depr…
- 2 The Depression Diary: Art, Music, Food Can Fight Blues
Turn The Frown Upside Down
On certain days, it’s normal to feel low or anxious. It could be work-related pressure or a personal problem that is not in your control. The mood you are in can be influenced by factors like stress, the external environment, poor sleep, genetics and nutritional deficiencies.
In such a scenario, ensuring a proper diet can not only help your immune system and heart function better, but can also improve your mood, sleep and proper digestion. Food plays a major role in our life – from aiding overall health to keeping your well-being in check.
While following a routine and maintaining a healthy lifestyle is important, one can add vegetables, fruits, legumes, whole grains, lean protein, omega-3 and fermented foods, dark chocolate, oats, berries, and nuts and seeds to their daily diet to combat anxiety and stress.
On World Mental Health Day, Daljit Kaur, Chief Dietician at Fortis Escorts Heart Institute, New Delhi; Dr Preeti Parakh, Psychiatrist and Head at Mpower – The Centre (Kolkata); Simrun Chopra, Deep Health Coach and founder at Nourish with Sim; and Dr. Roma Kumar, Chief Psychologist at Emotionally.in, suggest consuming a well-balanced meal, rich in nutrient-dense carbs, fats and proteins that will help you feel better.
Go Bananas Over Bananas
One large banana provides 16 grams of sugar and 3.5 grams of fiber. When paired with fibre, sugar is released slowly into your bloodstream, allowing for stable blood sugar levels and better mood control. Blood sugar levels that are too low may lead to irritability and mood swings.
It is also rich in Vitamin B6, which helps synthesise feel-good neurotransmitters like dopamine and serotonin.
Bananas are an excellent source of prebiotics, a type of fibre that helps feed healthy bacteria in your gut. A robust gut microbiome is associated with lower rates of mood disorders.
Other than bananas, having a visually appealing and aesthetically pleasing fruit salad or fruit platter can bring some immediate respite. The Vitamin A and C-rich platter can help in uplifting the food.
Green vegetables, just like fruits, are rich in B-complex vitamins and antioxidants. B-complex vitamins are necessary for the functioning of brain cells and deficiency of these can lead to memory loss amongst other problems. Deficiency of folate, a B-complex vitamin, has been shown to be linked with depression.
Gut & Mind Booster
Fermented foods are packed with excellent gut bacteria and anti-inflammatory properties.
The fermentation process allows live bacteria to thrive in foods that are then able to convert sugars into alcohol and acids. During this process, probiotics are created which increase serotonin levels, allowing the good bacteria in the gut to survive.
Serotonin is a neurotransmitter that affects many facets of human behaviour such as mood, stress response, appetite and sexual drive. Up to 90 per cent of your body’s serotonin is produced by your gut microbiome, or the collection of healthy bacteria in your gut.
Probiotics such as yogurt and curd can reduce symptoms of depression, by improving the bacterial flora in the gut. The gut brain axis involves chemical signalling between the brain and the bacteria in the gut. Disruption in this signalling can cause symptoms of irritable bowel syndrome, anxiety and depression.
Curd, lassi, buttermilk (chaas) and other fermented foods have positive effects on brain health especially for reducing anxiety, stress, and depression. Other fermented foods include kimchi, kefir, kombucha and sauerkraut can also help improve gut health and mood.
However, it’s important to note that not all fermented foods like beer, some breads and wine (due to the process used for cooking and filtering) are significant sources of probiotics.
A diet rich in antioxidants is necessary for preventing age-related damage of brain cells, and can help manage inflammation associated with depression and other mood disorders or stress.
Omega-3 fatty acids are used in building and repairing brain cells. Any deficiency of these can cause problems in memory and cognition. Fish like Rawas and Hilsa, and avocado have strong positive relationships with cognitive function as well as mental health.
Berries pack a wide range of antioxidants and phenolic compounds, which play a key role in combating oxidative stress — an imbalance of harmful compounds in the body. They are particularly high in anthocyanins, a pigment that gives certain berries their purple-blue colour.
Healthy Meal Box
Whole grains and pulses are good sources of essential amino acids and B-complex Vitamin, both of which are necessary for synthesis of neurotransmitters like serotonin and dopamine. These chemicals influence both our mood and thought.
Another iron and fibre-rich whole grain – oats – can also help in preventing sluggishness and lethargy, and keep the energy levels up and pumping. It provides 8 grams of fibre in a single raw cup. Fibre helps slow your digestion of carbs, allowing for a gradual release of sugar into the bloodstream to keep your energy levels stable.
Oats, a daily mood booster, can be enjoyed in many forms, such as overnight oats, oatmeal, muesli and granola.
In addition to being high in fibre and plant-based protein, beans and lentils are full of feel-good nutrients. They’re an excellent source of Vitamin B that helps improve the mood by increasing levels of neurotransmitters like serotonin, dopamine, norepinephrine and gamma amino butyric acid – all of which are important for regulating the mood.
Furthermore, Vitamin B plays a key role in nerve signalling, which allows proper communication between nerve cells. Low levels of Vitamin B, especially B12 and folate, have been linked to mood disorders, such as depression or anxiety.
Finally, they’re a good source of zinc, magnesium, selenium, and non-heme iron, which may likewise elevate your spirits.
First comprehensive review
There has been extensive research on the serotonin system since the 1990s, but it has not been collected systematically before. We conducted an “umbrella” review that involved systematically identifying and collating existing overviews of the evidence from each of the main areas of research into serotonin and depression. Although there have been systematic reviews of individual areas in the past, none have combined the evidence from all the different areas taking this approach.
One area of research we included was research comparing levels of serotonin and its breakdown products in the blood or brain fluid. Overall, this research did not show a difference between people with depression and those without depression.
Another area of research has focused on serotonin receptors, which are proteins on the ends of the nerves that serotonin links up with and which can transmit or inhibit serotonin’s effects. Research on the most commonly investigated serotonin receptor suggested either no difference between people with depression and people without depression, or that serotonin activity was actually increased in people with depression – the opposite of the serotonin theory’s prediction.
Research on the serotonin “transporter”, that is the protein which helps to terminate the effect of serotonin (this is the protein that SSRIs act on), also suggested that, if anything, there was increased serotonin activity in people with depression. However, these findings may be explained by the fact that many participants in these studies had used or were currently using antidepressants.
We also looked at research that explored whether depression can be induced in volunteers by artificially lowering levels of serotonin. Two systematic reviews from 2006 and 2007 and a sample of the ten most recent studies (at the time the current research was conducted) found that lowering serotonin did not produce depression in hundreds of healthy volunteers. One of the reviews showed very weak evidence of an effect in a small subgroup of people with a family history of depression, but this only involved 75 participants.
Very large studies involving tens of thousands of patients looked at gene variation, including the gene that has the instructions for making the serotonin transporter. They found no difference in the frequency of varieties of this gene between people with depression and healthy controls.
Although a famous early study found a relationship between the serotonin transporter gene and stressful life events, larger, more comprehensive studies suggest no such relationship exists. Stressful life events in themselves, however, exerted a strong effect on people’s subsequent risk of developing depression.
Some of the studies in our overview that included people who were taking or had previously taken antidepressants showed evidence that antidepressants may actually lower the concentration or activity of serotonin.
The Depression Diary: Art, Music, Food Can Fight Blues
The Depression Diary: Art, Music, Food Can Fight Blues
Depression feels different for different people. It can look like the bitter cold of January for some or a manic Monday to others. But, there are some simple life-hacks that help us keep this fiend in check. Here they are:
Create Your Eden
Getting your hands dirty in the garden can boost your happy hormone, serotonin. So, grow some plants (even if they don’t live long).
Songs For The Soul
Tune into your playlist daily. Clinical research shows music can keep depression at bay.
Phone A Friend
Sometimes, we all feel at our lowest. That’s when we need people who can make us feel shiny again.
Paint the pain, dullness or irritation. Give the burden to the canvas. You will feel much lighter.
Not supported by the evidence
The serotonin theory of depression has been one of the most influential and extensively researched biological theories of the origins of depression. Our study shows that this view is not supported by scientific evidence. It also calls into question the basis for the use of antidepressants.
Most antidepressants now in use are presumed to act via their effects on serotonin. Some also affect the brain chemical noradrenaline. But experts agree that the evidence for the involvement of noradrenaline in depression is weaker than that for serotonin.
There is no other accepted pharmacological mechanism for how antidepressants might affect depression. If antidepressants exert their effects as placebos, or by numbing emotions, then it is not clear that they do more good than harm.
Although viewing depression as a biological disorder may seem like it would reduce stigma, in fact, research has shown the opposite, and also that people who believe their own depression is due to a chemical imbalance are more pessimistic about their chances of recovery.
It is important that people know that the idea that depression results from a “chemical imbalance” is hypothetical. And we do not understand what temporarily elevating serotonin or other biochemical changes produced by antidepressants do to the brain. We conclude that it is impossible to say that taking SSRI antidepressants is worthwhile, or even completely safe.
If you’re taking antidepressants, it’s very important you don’t stop doing so without speaking to your doctor first. But people need all this information to make informed decisions about whether or not to take these drugs.
(The article has been syndicated by PTI via The Conversation)