Seasonal Depression

Seasonal depression* affects 1 in 10 people

Winter is here, synonymous for some of a serious blow blues. In October, the days get shorter and the sky turns gray regularly, perhaps as well as your mood. The winter blues is not a legend, but especially its severe variant, genuine seasonal depression, which requires support. Seasonal depression may affect 1 in 10 people on average in Europe, with regional differences, as in the north where the winter is longer, temperatures are lowest and where the days are shorter. For example, this concerns one in two people in Scandinavia. Furthermore, women seem to be more affected than men, as it’s the case for conventional chronic depressions which are not seasonal factors (unemployment, bereavement, illness, etc.).

What are the signs of seasonal depression?

In the case of winter blues we feel a little worse in the winter and we are a little faster tired, but nothing too annoying or lasting. However, depression induced by the change of season has clear symptoms : the person feels sad, has dark thoughts, spends a lot of time in bed, give up his favorite activities and sees his appetite increasing, especially for sweet foods which makes him gain weight. This is a cyclical phenomenon that disappears in the spring but returns almost every year, and which could promotes the appearance of genuine chronic depressions.

All depression accelerate aging

People with depression exhibit early aging signs. Researchers have recently found that depression aged faster the cells of patients. Depressive develop more age-related diseases (type 2 diabetes, dementia, cancer). Depression directly decreases cell survival, but the unhealthy lifestyle of depressed people is involved too (lack of exercise, poor diet, excessive alcohol consumption). Depressed or formerly depressed individuals exhibit early aging of 4 to 6 years on average. In addition to accelerating aging, depression increases social isolation, directly impacts the family/friends environment, reduces business productivity, triggering heavy therapeutic solutions which are often inappropriate.

Light as a therapy against seasonal depression

1 / Seasonal depression is the result of more or less abrupt changes of exposure to sunlight. How does light to regulate mood ? The light is captured by specific cells in our retina, to translate it into a nervous message to the brain, where the biological clock is located. This triggers the production of a hormone, the melatonin, which regulates the biological clock of all organs. Melatonin is produced at night but in the winter the holiday falls earlier and for some people, adjusting their biological clock is wrong. It’s this disruption of the circadian rhythm (day/night) which generates anxiety, irritability, malaise, symptoms of seasonal depression.

2 / So light therapy is recommended to those affected by seasonal depression: a noninvasive technique without danger to skin and eyes! You are exposed to a special light diffusing a high intensity light (10,000 lux), as soon as possible after waking in the morning to give a clear signal to the body. For comparison, in daylight in good weather light intensity is about 100,000 lux, while an artificially lit room of only 200-300 lux. The patient is exposed for 30 minutes every day for 2 to 6 weeks: work or play close to the high intensity light is enough. It’s possible to make the sessions in a doctor’s office or invest in a lamp. Light therapy is sufficient in 75% of cases to alleviate winter depression. Antidepressants – which are sometimes prescribed when physician didn’t make the link between depression and the change of season – are less effective and have side effects.

3 / Of course, without waiting for a stroke of blues, schedule yourself a smooth transition between summer and winter by promoting all that’s contacted with the light of day: go to work on foot, go out for lunch, read by a window, etc. Avoid in any case to stay locked in dark places, keep the same schedules for wake up, sleep and to take your meals as during summer, although overnight printing is more present.

4 / Finally, light therapy is useful in other circumstances. In particular, it potentiates the action of antidepressants drugs in patients who have classic depression (+ 30% improvement in chronic depression). Light therapy is also useful in the shift phases as the “jet lag”, mainly due to a West to East travel, and also effective in case of shifting of the internal biological clock like the one experienced by teenagers who sleep late and get up late.


Dr. Adrien and the pharmacists

* Seasonal depression is also known as Seasonal Affective Disorder (SAD)

Reference : VU Medical Center, Amsterdam University,

Reference : Dr Adeline Gaillard and Dr David Gourion, Sainte Anne Psychiatric Hospital, Paris

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