While the rates of full OCD are pretty consistent across different countries and age groups, the rates of milder OCD symptoms vary a lot more – anywhere from 2% to 19% of people. This big difference might be because the studies looked at different age groups and were done in different countries. One study found that mild symptoms were about equally common in women (9.3%) and men (10.1%). But two studies of teenagers found that girls had higher rates of mild symptoms than boys, while one study of children found that boys were more likely than girls to have at least one OCD symptom.