Thumbsucker (2005)

In the strange land known as suburbia, introverted adolescent Justin (Lou Pucci) spends the majority of his life pining after his attractive classmate Rebecca (Kelli Garner) and nervously sucking his thumb when he's alone. Oddly, after receiving some New Age advice from his spacey orthodontist, Perry (Keanu Reeves) -- and a helpful dose of prescription pills -- Justin becomes the outspoken star of his school's debate club. His extroverted persona, however, causes an all-new set of problems.