With the arrival of the cold season, besides cold-driven nuisance, some persons experience drawbacks regarding the general state, lack of energy and depression of unknown origin. It was scientifically ascertained that the lack of light favors the production of melatonin by the pineal gland, a hormone inducing sleep. That is why, during the cold seasons when days are shorter and the sunlight is scarce, we often feel sleepy or drowsy. Also, even during spring and summer, if the tendency is to keep most of the time indoors at home or at the office, the effect may be similar, though not as severe.
Well, if drowsiness were the only impact generated by season changes, things would be easier to solve (with a little coffee maybe!). The problem is that melatonin secretion is synchronized with the production of a neurotransmitter, serotonin, which is involved in several physiological processes such as temperature, blood-pressure regulation and in neuropsychological functions such as appetite, memory and mood. The two do not work together at the same time. When melatonin is secreted, serotonin production is inhibited. Lack of serotonin causes disorders such as...