Depression is rated by the World Health Organisation as the leading cause of disease burden amongst high income countries. Depression is characterised by feelings of worthlessness or guilt, poor concentration, loss of energy, fatigue, thoughts of suicide or preoccupation with death, loss or increase of appetite and weight, a disturbed sleep pattern, slowing down (both physically and mentally), agitation (restlessness or anxiety). If you think you are feeling down, try our free depression test questionnaire to check your mood.

There are many factors that can contribute to the development of depression such as psychological issues or biochemical imbalances, and triggers such as major stress or trauma.

There are also a number of nutritional imbalances that can make you prone to depression such as:

        • Essential fats, do you need more Omega 3?
        • Homocysteine, is it too high?
        • Serotonin levels, do they need boosting with amino acids?
        • Blood sugar balance
        • Levels of the nutrients chromium and Vitamin D
        • Food intolerances, could they be making you sad?


To find out more about these factors read on, or click on our Action Plan for Depression.  

Watch Fran, a client of the Brain Bio Centre clinic, talking about how a nutritional approach helped support her depression:

More information about the Brain Bio Centre clinic where nutritional imbalances can be analysed can be found here


In Britain, 1 in 20, or around 3 million people, are diagnosed with depression. Unipolar Depression is rated by the World Health Organization as the leading cause of disease burden amongst high-income countries.

The classic symptoms of depression include feelings of worthlessness or guilt, poor concentration, loss of energy, fatigue, thoughts of suicide or preoccupation with death, loss or increase of appetite and weight, a disturbed sleep pattern, slowing down (both physically and mentally), agitation (restlessness or anxiety).

There are 2 major classifications of depression: typical and atypical. Typical depression tends to feature loss of weight, appetite and difficulty sleeping whereas atypical depression tends to include weight gain, increased appetite and excessive sleepiness and/or sleeping.


Depression is diagnosed on the basis of symptoms in a questionnaire test, the most common being the Hamilton Rating Scale of Depression, or HRS for short. This contains questions about your mood, guilt feelings, suicidal thoughts, insomnia, agitation, anxiety, physical problems, sex drive, and so on. Depending on your test score on these questions, you will be diagnosed with either “mild,” “moderate,” or “severe” depression. Here’s a simplified depression test questionnaire to check your mood.

Check yourself out on this simplified Mood Check.


There are many factors that can contribute to the development of depression. There might be underlying biochemical or psychological issues that predispose an individual to depression. There might be a trigger such as a stressful event, a bereavement, loss of a job, or break up of a relationship. If you are suffering with a low mood, whether you consider that it is depression or not, you should see your GP who can rule out medical causes, recommend counselling, cognitive behavioural therapy and psychotherapy, and assess your medication. Exercise is also very important and there’s lots of evidence that regular exercise boosts mood, especially if you’re able to exercise outdoors in a green environment. Even a walk in the park or a stroll by the river is thought to be beneficial.

There are a number of nutritional imbalances that can make you prone to depression. These are:

        • Essential fats, do you need more Omega 3?
        • Homocysteine level, is it too high, corrected with B vitamins?
        • Serotonin levels, do they need boosting with amino acids?
        • Blood sugar balance, is yours within the healthy range?
        • Chromium, are you getting enough?
        • Vitamin D, the sunshine vitamin
        • Food intolerances, could food could be making you sad?

To find out more about these factors read on, or click on our Action Plan for Depression


Increase your omega-3 fats

Omega-3 fats are called essential fats, because unlike some other substances, they can’t be manufactured within the human body, and therefore it is essential that you take them in through your diet. The richest dietary source is from oily fish such as salmon, sardines, mackerel, pilchards, herring, trout and fresh but not tinned tuna. Surveys have shown that the more fish the population of a country eats the lower is their incidence of depression. There are two key types of omega-3 fats, EPA and DHA and the evidence suggests that it’s the EPA which seems to be the most potent natural anti-depressant.

There have been six double-blind placebo controlled trials to date, five of which show benefit. The first trial by Dr Andrew Stoll from Harvard Medical School, published in the Archives of General Psychiatry, gave 40 depressed patients either omega 3 supplements versus placebo and found a highly significant improvement. The next, published in the American Journal of Psychiatry, tested the effects of giving twenty people suffering from severe depression, who were already on anti-depressants but still depressed, a highly concentrated form of omega 3 fat, called ethyl-EPA versus a placebo. By the third week the depressed patients were showing major improvement in their mood, while those on placebo were not. A recent pooling of trials (a meta-analysis) which looked at all good quality trials of omega-3 fats and mood disorders concluded that omega-3 fats reduced depressive symptoms by an average of 53% and that there was as correlation between dose and depressive symptom improvement, meaning that higher dose omega-3 was more effective than a lower dose. Of those that measured the Hamilton Rating Scale, including one ‘open’ trial, not involving placebos, the average improvement in depression was approximately double that shown by anti-depressant drugs, without the side-effects. This may be because omega 3s help to build the brain’s neuronal (brain cell) connections as well as the receptor sites for neurotransmitters; therefore, the more omega-3s in your blood, the more serotonin you are likely to make and the more responsive you become to its effects.

Where’s the evidence? Search our evidence database for a list of scientific studies on omega 3 and depression.

Side effects? Very occasionally, when starting omega-3 fish oil supplementation, some people can get slightly loose bowels or fish-tasting burps, but this is quite rare. Supplementing fish oils also reduces risk for heart disease, reduces arthritic pain and may improve memory and concentration.

See action plan for our recommendations.

Increase your intake of B vitamins

People with either low blood levels of the B-vitamin folic acid, or high blood levels of the amino acid homocysteine (a sign that you are not getting enough B6, B12 or folic acid), are both more likely to be depressed and less likely to get a positive result from anti-depressant drugs. In a study comparing the effects of giving an SSRI with either a placebo or with folic acid, 61% of patients improved on the placebo combination but 93% improved with the addition of folic acid. But how does folic acid itself, a cheap vitamin with no side-effects, compare to anti-depressants?

Three trials involving 247 people address this question. Two involving 151 people assessed the use of folic acid in addition to other treatment, and found that adding folic acid reduced HRS scores on average by a further 2.65 points. That’s not as good as the results with 5-HTP (discussed below) but as good, if not better than antidepressants. These studies also show that more patients treated with folate experienced a reduction in their HRS score of greater than 50% after ten weeks compared to those on anti-depressants.

Having a high level of homocysteine, a toxic amino acid found in the blood, doubles the odds of a woman developing depression. The ideal level is below 7, and certainly below 10. The average level is 10-11. Depression risk doubles with levels above 15. The higher your level the more likely folic acid will work for you.

Folic acid is one of seven nutrients – the others being B2, B6, B12, zinc, magnesium and TMG – that help normalise homocysteine. Deficiency in vitamin B3, B6, folic acid, zinc and magnesium have all been linked to depression. Having a low homocysteine means your brain is good at ‘methylating’ which is the process by which the brain keeps it’s chemistry in balance. So it makes sense to both eat wholefoods, fruits, vegetables, nuts and seeds, high in these nutrients and supplementing a multivitamin.

Side effects? There are none, except lower risk for heart disease, strokes, Alzheimer’s and improved energy and concentration. However, if you are B12 deficient (most likely if you are elderly, vegan, or are on medication to reduce stomach acid), taking folic acid on its own can mask the B12 deficiency symptoms, but the underlying nerve damage caused by B12 deficiency anaemia can persist. So, don’t take folic acid without also supplementing vitamin B12 (sub-lingual forms are better absorbed, particularly in the elderly).

See action plan for our recommendations.

Boost your serotonin with amino acids

Serotonin is made in the body and brain from an amino acid called tryptophan. Tryptophan is then converted into another amino acid called 5-Hydroxy Tryptophan (5-HTP), which in turn is converted into the neurotransmitter serotonin. Tryptophan can be found in the diet; it’s in many protein rich foods such as meat, fish, beans and eggs. 5-HTP is found in high levels in the African Griffonia bean, but this bean is not a common feature of most people’s diet. Just not getting enough tryptophan is likely to make you depressed; people fed food deficient in tryptophan became rapidly depressed within hours.

Both tryptophan and 5-HTP have been shown to have an antidepressant effect in clinical trials, although 5HTP is more effective - 27 studies, involving 990 people to date, most of which proved effective. . So how do they compare with anti-depressants? In play-off studies between 5-HTP and SSRI antidepressants, 5-HTP generally comes out slightly better. One double-blind trial headed by Dr. Poldinger at the Basel University of Psychiatry gave 34 depressed volunteers either the SSRI fluvoxamine (Luvox) or 300 mg of 5-HTP. At the end of the six weeks, both groups of patients had had a significant improvement in their depression. However, those taking 5-HTP had a slightly greater improvement, compared to those on the SSRI, in each of the four criteria assessed—depression, anxiety, insomnia, and physical symptoms—as well as their own self-assessment, although this improvement was not statistically significant.

Since anti-depressant drugs, in some sensitive people, can induce an overload of serotonin called ‘serotonin syndrome’ characterised by feeling hot, high blood pressure, twitching, cramping, dizziness and disorientation, some concern has been expressed about the possibility of increased risk of serotonin syndrome with the combination of 5-HTP and an SSRI drug. The balance of evidence suggests that there is little to no risk, however, if you wish to take 5-HTP or tryptophan alongside a serotonergic drug (SSRI or tricyclic antidepressant that boosts serotonin levels), you should first consult your prescribing doctor.

Exercise, sunlight and reducing your stress level also tend to promote serotonin.

Side-effects? Some people experience mild gastrointestinal disturbance on 5-HTP, which usually stops within a few days. Since there are serotonin receptors in the gut, which don’t normally expect to get the real thing so easily, they can overreact if the amount is too high, resulting in transient nausea. If so, just lower the dose or take it with food.

See action plan for our recommendations.

Balance your blood sugar

There is a direct link between mood and blood sugar balance. All carbohydrate foods are broken down into glucose and your brain runs on glucose. The more uneven your blood sugar supply the more uneven your mood. In fact, our experience at the Brain Bio Centre is that poor blood sugar balance is often the single-biggest factor in mood disorders amongst the people that seek our advice.

Eating lots of sugar is going to give you sudden peaks and troughs in the amount of glucose in your blood; symptoms that this is going on include fatigue, irritability, dizziness, insomnia, excessive sweating (especially at night), poor concentration and forgetfulness, excessive thirst, depression and crying spells, digestive disturbances and blurred vision. Since the brain depends on an even supply of glucose it is no surprise to find that sugar has been implicated in aggressive behaviour, anxiety, and depression, and fatigue .

Lots of refined sugar and refined carbohydrates (meaning white bread, pasta, rice and most processed foods,) is also linked with depression because these foods not only supply very little in the way of nutrients but they also use up the mood enhancing B vitamins; turning each teaspoon of sugar into energy needs B vitamins. In fact, a study of 3,456 middle-aged civil servants, published in British Journal of Psychiatry found that those who had a diet which contained a lot of processed foods had a 58% increased risk for depression, whereas those whose diet could be described as containing more whole foods had a 26% reduced risk for depression.

Sugar also diverts the supply of another nutrient involved in mood – chromium. This mineral is vital for keeping your blood sugar level stable because insulin, which clears glucose from the blood, can’t work properly without it. There is more on chromium below.

The best way to keep your blood sugar level even is to eat what is called a low Glycemic Load (GL) diet and avoid, as much as you can, refined sugar and refined foods, eating instead whole foods, fruits, vegetables, and regular meals. The book, the Holford Low GL Diet Bible, explains exactly how to do this so this is a great resource if you really want to improve your blood sugar balance. Caffeine also has a direct effect on your blood sugar and your mood and is best kept to a minimum, as is alcohol.

Where’s the evidence? Search our evidence database for a list of scientific studies on sugar, caffeine and depression.

Side effects? None.

See action plan for our recommendations.

Up your intake of chromium

This mineral is vital for keeping your blood sugar level stable because insulin, which clears glucose from the blood, can't work properly without it. In fact it turns out that just supplying proper levels of chromium to people with atypical depression can make a big difference.

If you answer yes to a five or more of these questions and you might be suffering from atypical depression.

        • Do you crave sweets or other carbohydrates?
        • Do you tend to gain weight?
        • Are you tired for no obvious reason?
        • Do your arms or legs feel heavy?
        • Do you tend to feel sleepy or groggy much of the time?
        • Are your feelings easily hurt by the rejection of others?
        • Did your depression begin before the age of 30?

It is called atypical because in ‘classic’ depression people lose their appetite, don’t eat enough, lose weight and can’t sleep whereas with atypical, the opposite is generally true. Atypical depression affects anywhere from 25 to 42 percent of the depressed population, and an even higher percentage among depressed women so it’s extremely common rather than being ‘atypical’. A chance discovery by Dr Malcolm McLeod, clinical professor of psychiatry at the University of North Carolina, suggested that people who suffer with ‘atypical’ depression might benefit from chromium supplementation.

In a small double-blind study McLeod gave ten patients suffering from atypical depression chromium supplements of 600mcg a-day and five others a placebo for eight weeks. The results were dramatic. Seven out of ten taking the supplements showed a big improvement, versus none on the placebo. Their Hamilton Rating Score for depression dropped by an unheard of 83%; from 29 - major depression - to 5 – not depressed. A larger trial at Cornell University with 113 patients has confirmed the finding. After eight weeks 65% of those on chromium had had a major improvement, compared to 33% on placebos.

In our experience at the Brain Bio Centre, people with atypical depression generally have other symptoms of poor blood sugar balance, so if this sounds like you, then in addition to supplementing chromium, you should focus on improving blood sugar balance.

Side effects? None, except more energy and better weight control. Chromium, if taken in the evening, can increase energy and hence interfere with sleep.

See action plan for our recommendations.

Bring on the sunshine

Known as the ‘sunshine vitamin’, around 90% of our vitamin D is synthesised in our skin by the action of sunlight. Vitamin D deficiency is increasingly being recognised as a common problem around the globe and may be implicated in depression, particularly if you feel worse in winter.

You are most at risk for vitamin D deficiency if you are elderly (since your ability to make it in the skin reduces with age), dark-skinned (you require up to 6 times more sunshine than a light-skinned person to make the same amount of vitamin D), overweight (your vitamin D stores may be tucked away within your fat tissue), or you tend to shy away from the sun – covering up and using sun-block. Of course, you should never risk your skin health by getting sun-burned.

Side effects? None

See action plan for our recommendations.

Bad mood foods

Some foods are associated with mood problems. For example, in a huge population study, Coeliac Disease (a severe intolerance to gluten – the protein found in wheat, rye and barley) was associated with an 80% increased risk for depression. It is thought that Coeliac Disease is vastly underdiagnosed in the UK. Your GP can test for it, and should test you if you have fluctuating digestive symptoms including diarrhoea, constipation or bloating, and especially if you have unexplained anaemia. In fact, you can have mood symptoms relating to gluten, even without Coeliac Disease.

At the Brain Bio Centre we routinely test individuals with low mood or motivation for food intolerance. It is not at all uncommon for us to find that putting a person on the allergy-free diet they need relieves symptoms of depression, insomnia or anxiety.

Peter is a case in point. When he came to the Brain Bio Centre he had had a long history of mental health problems, which left him unable to work, and years of trying various anti-depressants. He had severe periods of depression, along with many unpleasant side effects from the medication. He felt he wanted to be able to “enjoy life to the full” but wasn’t able to.

When we tested him for IgG based food intolerances he reacted to many foods including gluten, egg white, corn and barley. After removing these foods from his diet, along with a supplement programme to support his general health he began to experience fewer spells of feeling down and had noticed what he described as a “huge improvement” in his general wellbeing and mood.

So if you suffer from poor concentration, insomnia, anxiety or other symptoms of depleted mental health, it’s well worth investigating whether food intolerances play a part.

If you score high on the following questions there’s a good chance you have hidden food intolerances.

Your food sensitivity check.

Side effects? None, if changes are made with professional guidance. Dramatic changes to diets without professional supervision may cause nutrient deficiencies, especially over the longer term.

See action plan for our recommendations.


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