Next highest incidence was in the winter and spring. Studies at Kansas State University show that a humid condition, which has a negative effect on a man, has to get appreciably worse before the average woman is bothered by it. Studies also show that when people are feeling depressed, their mood is reinforced by such weather conditions as warm, dry winds, and cold fronts. They are real. At Wake Forest University, researchers studied 98 coeds and found that they were much more likely to display negative, downbeat attitudes during the premenstrual phase.
Hormonal changes are to blame.
It's also noted that psychological factors play an important part, especially in women who associate menstruation with pain and inconvenience. This may be anything that will stimulate you and give you no chance to brood.