прочитать буквами.the usa about 6-20% of people have sad and it is common in other countries like the uk and sweden.people get sad in autumn and winter,when the days are shorter and there is less daylight.it is more common in women than in men.people with sad usually sleep a lot amd feel tired all the time.they also eat a lot of sweet food and feel depressed.the answer is is bright light.people with sad should use a light box for half an hour a day.or you can go on holiday to a sunny country,of course.