JAMA 100 Years Ago Section Editor: Jennifer Reiling, Assistant Editor.
During the past six or seven weeks the bright days have been exceedingly rare, even for this rather gloomy season of the year. According to the weather reports, there were less than five clear days throughout most of the northern part of the region east of the Mississippi during December. Since then weather conditions have not ameliorated and the first half of January has been quite as gloomy. Under these circumstances a definite increase in the amount of catarrhal disease of the respiratory tract is always noted, and it seems clear that the absence of sunlight encourages the propagation of various germs in the air, which prove the source of infective disorders when inhaled.
DARK DAYS AND PHYSICAL AND MENTAL DEPRESSION.. JAMA. 2007;297(3):322. doi:10.1001/jama.297.3.322-a