Gloomy weather getting you down? All you need to know about Seasonal Affective Disorder.

Gloomy weather getting you down? All you need to know about Seasonal Affective Disorder.

Seasonal Affective Disorder (SAD) is a mood disorder associated with cyclical changes in the seasons and weather. It’s categorized with Depression and is nothing to be ashamed of, yet many underplay how serious the outcomes of this disorder are.

It’s believed that in the UK alone over 6% of the population will experience symptoms of SAD. It is more common in women than it is in men and is linked to geographical location in the world. People located further from the equator will be more at risk to this disorder than those close to it[1].

What is SAD?

Much like is name suggests it is a disorder linked to the seasons, sometimes referred to as the ‘Winter blues’. The most severe symptoms occur between December to February. At the time the cause is idiopathic, or unknown. There are 3 main theories, of which treatment is based on, these are:

  • Melatonin Production. Melatonin is a hormone produced at night, usually when you are sleeping. It is responsible for the Circadian rhythms of the body, e.g. those that are responsible for your sleep and awake cycles. It has been clinically shown that people with SAD produce higher levels of Melatonin than most other people.
  • Circadian Rhythms. This is linked with the idea of Melatonin, however, the body uses sunlight to set its internal body clock. During the winter months sunlight hours are cut short to as little a 7 hours in some cases. This can throw the body’s clock out of sync and cause symptoms SAD.
  • Serotonin Production. Serotonin is the “happy hormone” primarily responsible for stabilising mood, however it is also linked with appetite and sleep cycles. Serotonin depends on sunlight for production, hence why in SAD there is a reduction in of Serotonin leading to depressive symptoms[1].

What to look out for with SAD?

Symptoms of SAD reflect the complicated neurological causes of this disorder. The symptoms include lethargy and sleeping for long periods of time. This may also cause waking and rising in the morning to become more difficult. This general lack of energy will cause cravings for energy dense foods such as carbohydrates. This combination of decreased energy, movement and increased calories may lead to a sharp rise in weight. The person may also have a reduction in mood, causing irritability, feelings of despair and lack of interest for things they once loved [1].

Treatments for SAD

Treatments for SAD include the addition of light therapy, supplements and a dietary overhaul to best manage symptoms.

Light Box Therapy

According to the proposed causes of SAD, UV rays from the sun play a vital part in keeping the symptoms of SAD at bay. Therefore, it is highly recommended as a primary treatment that people with SAD purchase a light box. A light box artificially supplies UV light so that the body is tricked in thinking daytime light hours are longer than the seasons provide, thus improving symptoms. It has been clinically proven to be effective at treating and reducing symptoms of SAD[3].


Nutrition for SAD primarily focuses on topping up the nutrition the sun helps to provide and maintaining energy levels. It is suggested that people with SAD fight their cravings and avoid sugar, fat and salt laden foods, majority of which are found in processed snack foods, takeaways and desserts. Instead they are advised to concentrate on energy providing foods such as wholegrain and brown varieties of carbohydrates. These varieties are full of starch. Starch is a slow release energy molecule, as opposed to glucose which is a fast release molecule. White carbohydrate varieties are full of glucose which provides a very abrupt rise in blood glucose and a short release of energy. Whereas brown varieties are packed full of starch which will release a slow and sustaining amount of glucose over a long period of time, so fatigue can be avoided. Wholegrains are also packed full of B Vitamins which are essential for the conversion and metabolism of energy. B vitamins can be found in a wide range of fruit and vegetables.

Furthermore, the sun helps with the conversion of Serotonin and Vitamin D3. Serotonin is produced from the amino acid Tryptophan. This is then converted to 5-Hydroxytryptophan (5-HTP) and then Serotonin (5-HT). Tryptophan is found in foods such as cheese, milk, yoghurt, legumes and nuts. Typically if someone is lacking Serotonin they will be prescribed 5-HTP supplement. Vitamin D3 has recently raised its profile after scientific claims state that we do not get enough. The best source of Vitamin D3 is sunlight, but during certain seasons especially in the UK it is not possible to provide this. So it must be consumed via diet or supplement. Rich food source of Vitamin D include egg yolks, cheese, organ meats and oily fish.


Consuming all you need from your diet is not always possible especially if you have specifc dietary requirements (dairy free, vegan/vegetarian). Therefore, majority of the time supplements are recommended for people with SAD. Firstly, you may want to try Vitamin D3 Tablets or a Vitamin B complex tabletAdditionally, 5-HTP is often prescribed, this is the precursor to Serotonin and is extracted from seeds of the Griffonia Simplicifolia plant. 5-HTP naturally boosts the body’s Serotonin levels to alleviate the mood associated symptoms of SAD.

Don’t dismay as the winter months roll in, SAD does not have to be a feature of every winter. Carefully controlled diet and supplement intake used in conjunction with light therapy can help you to wave goodbye to the ‘winter blues’.


  1. Rull.G. (2016). Seasonal Affective Disorder. Available:
  2. NHS. (2015). Seasonal affective disorder (SAD) . Available:
  3. Tam.E, Lam.R, Levitt,A. (1995). Treatment of seasonal affective disorder: a review.. Canadian Journal of Psychiatry. 40 (8), Pg. 457-466.
  4. Brewer, S. (2002). Seasonal Affective Disorder. In: Grapevine Publishing Services The Daily Telegraph Encyclopedia of Vitamins, Minerals and Herbal Supplements. . London: Constable & Robinson. Pg. 546-538.
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