How can obsessive-compulsive disorder (OCD) affect a child?

As with adults, childhood obsessive-compulsive disorder consists of intrusive, unwanted thoughts (obsessions) that cause mounting tension that is sometimes relieved by repetitive actions (compulsions). The obsessions often involve a fear of some calamity, such as contracting a disease or the death of a parent. While adults with the disorder are usually aware that their symptoms are irrational and strange, even though they can't stop them, children lack this perspective and don't question the validity of their fears or the compulsive rituals they follow to cope with these thoughts.