Seasonal affective disorder affects 2 percent to 5 percent of Americans, causing them to feel depressed, irritable and listless during the winter months.

The University of Utah Neuropsychiatric Institute will host "Seasonal Affective Disorder: Shedding Light on Feeling S.A.D." a lecture by Joanne L. Brown, Ph.D. This free presentation will be Wednesday, Oct. 30, at 7:30 p.m. at the Neuropsychiatric Institute, 501 Chipeta Way.