Light therapy is indicated for people suffering from seasonal depression or seasonal affective disorder (ATS). Women between the ages of 20 and 40 are more likely to suffer from this disease. When ATS manifestations of depression are exacerbated in winter and subside in summer, with an increase in the number of Sunny days. It has long been observed that in the Northern latitudes, people are more likely to suffer from depression in the southern us States, this figure is 1-2% in the Northern reaches 10 %. According to some data, the prevalence of depression in Eskimos in Greenland reaches 80% of the total population.
The mechanism of exposure to light therapy is associated with the effect on metabolism in the body of melatonin, the hormone of the pineal gland, the secretion of which increases with the onset of darkness. The function of melatonin is associated with the regulation of human sleep, its secretion contributes to sleep, but at the same time there is an inverse relationship with the level of serotonin, the production of which decreases with increasing amounts of melatonin in the nervous tissue and Vice versa. As in other cases, biochemical disorders are not the only cause of depression, but rather serve as the basis for the emergence of a favorable background for its manifestation.
Exposing the patient to additional artificial irradiation with bright light, in many cases it is possible to achieve a positive result. Therapy usually lasts for a month, the effect is achieved in terms of several days to two weeks, the duration of the session from half an hour to several hours, depending on the response of the patient.
The convenience of this method is the possibility of its independent use, you can buy special lamps, up to 10 Lux, and practice at home. There are no side effects of the drawbacks – requires a certain amount of time, sometimes significantly.
Most recently, in April 2009, the results of a study by a doctor at the Falun psychiatric hospital in Sweden, Cecilia Rastad, were published. Dr. Rastad monitored 24 patients who received a course of light irradiation for 1.5–2 hours daily for 10 days. According to the data, more than half of the patients felt much better after the course, and they remained in good health for another month after receiving therapy. Characteristically, in Northern Sweden seizures of ATS is subject to 20 % of the population.
I personally have not tried light therapy, my depression did not differ seasonality, but the reviews of the method are good, as symptomatic therapy, it may be suitable for patients with appropriate manifestations of the disease. But we must be aware that in this way you can achieve only a temporary improvement in health, because the true causes of depression, the method can not have any impact.