Between 5 million and 7 million Americans are affected by obsessive compulsive disorder (OCD), which affects 1 out of every 200 school-age children, according to the Seattle OCD Support and Recovery Group. The organization is hosting a presentation on OCD and other anxiety disorders by Dr. David Kosins, 10 a.m. to noon Saturday, in the Glaser Auditorium at Swedish Medical Center First Hill Campus, 747 Broadway, Seattle. Kosins, who has specialized in OCD and related conditions for more than 20 years, will discuss associated conditions and treatment options with an emphasis on cognitive behavioral therapy (CBT). Seattle OCD Support and Recovery Group meets the third Saturday of each month at Swedish First Hill Campus; 206-781-5614 or www.ocdseattle.org.