Contamination: Kids with this obsession are sometimes called “germaphobes.” In schools, this plays out with kids worrying about other kids sneezing and coughing, touching things that might be dirty or getting sick in many different ways. This is the most common obsession seen in children.
Magical thinking: This is a kind of superstition, like “step on a crack, break your mother’s back,” taken to extremes. For example, kids might worry that their thoughts can cause someone to get hurt, or get sick. A child might think, “Unless my things are lined up in a certain way, mom will get in a car accident.”
Catastrophizing: Some kids easily jump to the conclusion that something terrible has happened. For example, if her parents are five minutes late picking her up, a girl who is catastrophizing might tell herself that they’ve decided to abandon her.
Scrupulosity: This is when kids have obsessive worries about offending God or being blasphemous in some way.
What ifs: Kids may be plagued by a lot of different kinds of thoughts about bad things they could do. “What if I hurt someone? What if I stab someone? What if I kill someone?”
The “just right feeling”: When OCD first develops, from about 6 to 9 years of age, kids may not know why they are doing something, but just that they need to do it until they get what we call the “just right feeling.” So: “I’ll line these things up until it just kind of feels right, and then I’ll stop.” And then over time — in the 9- to 12-year-old range — it evolves into magical thinking and becomes more superstitious in nature.