Fatigue, irritability... When light therapy can help us get through the winter.
Decreased energy, sleep disorders, anxiety... As winter approaches, and the lack of sunlight that goes with it, we can experience these symptoms. Light therapy can be a solution. Explanations with Doctor Thomas Schwitzer, psychiatrist, hospital practitioner at the Nancy Psychotherapeutic Centre (Meurthe-et-Moselle).
The days are getting shorter. The light is becoming rarer. In this winter period, some of us, affected by the lack of luminosity, feel a drop in energy and, in more serious cases, find their sleep disturbed or develop mood disorders. Light therapy can be a remedy for all these problems. If it proves effective in cases of the so-called winter blues, it is also effective in cases of more severe depression, confirms Dr Thomas Schwitzer, psychiatrist, lecturer at the University of Lorraine, hospital practitioner at the Nancy Psychotherapeutic Centre (university hospital centre for adult psychiatry in Greater Nancy directed by Professor Raymund Schwan).
What are the effects of a drop in luminosity on individuals?
A whole series of symptoms can develop when a subject lacks light: a drop in energy, greater fatigue, greater sensitivity to stress, irritability, etc. These things can be experienced without falling into an illness such as depression. When people present criteria for depression with a slowing down of brain and body activity, sleep and appetite disorders, loss of pleasure, inability to carry out activities of daily living, anxiety, and they meet the criteria of seasonality, i.e. they appear in winter but not in summer, we speak of "seasonal depression".
How will light therapy help people overcome the "winter blues" or so-called "seasonal depression"?
Light therapy, which consists of the emission of light by a fixed device - a lamp - or a portable device - glasses - will make it possible to provide the light that is missing because of the diminishing days. This light penetrates the eye, and more precisely the retina, and then reaches the centres that regulate circadian rhythms in the brain, i.e. the day-night and sleep-wake mechanism. The rhythms are regulated by various external markers, the most important of which is daylight. When there are variations in daylight, the circadian clock is disturbed and disrupted. The aim is to resynchronise circadian rhythms by regulating chemical molecules in the brain. The main chemical molecule affected is melatonin. Light therapy will restore and rebalance melatonin secretions over a day (day and night).
Can light therapy also treat non-seasonal depression?
Yes, it can. Light therapy can treat winter energy deficiency and, at a more advanced stage, seasonal depression. It is now also indicated for the treatment of non-seasonal depression. Recent studies have demonstrated the effectiveness and benefit of light therapy in the treatment of depression with or without medication. There are a number of patients who, today, will not respond to antidepressant treatment or will respond insufficiently. The origin of the depression may then be different. It is the melatonin pathway, regulated by light therapy, that can be explored.
What are the rules to follow when using light therapy?
Light therapy is used in a daily session, preferably in the morning, as early as possible, after waking up, which is traditionally between 7 and 9 am, for 20 to 30 minutes, over several weeks. The first effects, particularly on energy levels and sleep-wake rhythms, can be felt very quickly after a few days of use.
Can we trust the devices on the market?
The devices meet the quality criteria of a light therapy lamp and both fixed and portable devices are designed to deliver the right amount of light energy to enable a therapeutic function. The fixed lamps emit a white light with an illuminance of approximately 10,000 lux. It is a well-tolerated treatment.
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