seasonal affective disorder: how your circadian rhythm can dictate your wellbeing
Andy Garland Therapies - Counselling Cardiff - Mental Health Services Cardiff - Cardiff Therapists - seasonal affected disorder and sleep

As the nights get longer and the days darker, one of London's top doctors explains how to deal with SAD. The transition between the seasons can leave one in 20 of us with 'winter blues', 10 per cent of whom may then develop clinical depression. As autumn approaches, the days become shorter, colder and less sunlit.

SAD (Seasonal Affective Disorder) means the body begins to exhibit 'vegetative' symptoms (sleeping longer, feeling sluggish and craving carbs) before a pervasive low mood sets in around four weeks later. This form of hibernation can easily lead to insular and socially withdrawn patterns of behaviour. However, there are preventative tricks.

In recent times, we have discovered that SAD is related to our internal biological clock, triggering complex hormonal shifts due to the dwindling intensity and length of natural light exposure. The dull and shorter days can disrupt the brain's serotonin and melatonin levels. Here, the authority on this subject, Professor Russel Foster, a Circadian rhythm expert, shares his insight and advice on how to soften the impact of this physiological response.

light therapy

A special light box used in the home is one of the most valuable ways to replicate our light-sensitive Circadian rhythm. Be cautious when purchasing a light box, as they are not all regulated by the authorities and may not provide the correct intensity or evenness of light required. Ideally you should find one with a large screen that emits at least 10,000 LUX (a measure of light intensity). You should aim to get around 30 minutes of direct light exposure from your box every morning before 8am and will hopefully notice an improvement within three to four weeks. Do check with your GP, as some rare conditions could make light therapy unsuitable. For a reputable light box, search for 'MHRA registered lamp for SAD'. A couple of good brands are Buerer and Lumie.

A Dawn simulator is another device used to slowly and subtly illuminate the room early morning at around 5am over an hour or two, to mimic the sunrise. Here is a useful assessment to configure the best time and length of your light therapy, depending on your natural Circadian rhythm.

Andy Garland Therapies - Counselling Cardiff - Mental Health Services Cardiff - Cardiff Therapists - seasonal affected disorder and sleep

It is also important to get out into natural light and walk for 20 to 30 minutes, early in the day if possible. The natural light, exercise and serenity of open spaces can help to lift the mood and assist with your circadian rhythm.

psychological treatment

There is a more structured psychological approach to challenging SAD, and that is through CBT (Cognitive Behavioural Therapy). This is usually led by a qualified therapist, and can also be effective for other forms of anxiety and depression.

The Scandinavians have some of the shortest days over winter, with lower light levels. Their cultural practices adjust the mindset and offer a more positive take on the winter months. Known as 'Hygge' 'Mys' or 'Koselig' (Danish, Swedish or Norwegian). This loosely translates to a sense of cosiness. Picture crackling fires, candles, warm blankets, cashmere socks, comfort food and family time. They have conditioned themselves to enjoy the changes, rather than succumb to the dreariness of winter.

supplements and lifestyle

As mentioned, try to get some form of regular exercise (ideally outside) and look after your nutrition. Other techniques to manage mental health can be found in my previous article. It has been postulated that Vitamin D supplementation may help with SAD, but there is no strong evidence. However, most of the population does have a Vitamin D deficiency over the winter period, which in itself can affect mood and immunity. So it is generally a good idea to supplement around 1000-2000iu daily over the winter months. Other supplements which have been cited but lack evidence are 5-HTP, St John's Wort and Omega fish oils.


If you are in the grip of depression despite trying the methods above, you should contact your doctor, and as a last resort consider an antidepressant. This may help to reverse the depleted serotonin suspected in SAD.

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