Thumbsucker is a 2005 American independent comedy-drama film written and directed by Mike Mills and starring Lou Taylor Pucci , Tilda Swinton , Vincent D'Onofrio , Kelli Garner , Benjamin Bratt , Vince Vaughn , and Keanu Reeves . The plot focuses on Justin Cobb, a teenager in suburban Oregon , as he copes with his thumb-sucking problem, romance, and his diagnosis with ADHD and subsequent experience using Ritalin . The screenplay was adapted from the 1999 Walter Kirn novel of the same name . Swinton also served as an executive producer.