Many people are able to brush off the occasional intrusive thought and move on quickly. People with OCD, on the other hand, can get stuck trying to figure out what the thought means—and whether they might act on it. “We stop and we treat that thought as super important and meaningful,” says Alissa Jerud, a clinical psychologist and clinical assistant professor of psychiatry at the University of Pennsylvania.

Intrusive thoughts can feel especially disturbing because they often involve someone or something the person cherishes. “We tend to have intrusive thoughts about the things we care most about,” Jerud says.

Some of Jerud’s patients have kept their intrusive thoughts to themselves for 20 years before telling her. They might be thinking: “Why am I having these thoughts? What does it say about me? Maybe I’m a monster,” she says.

A calm, compassionate response can make it easier to keep talking. “It can help them feel like there’s hope,” Jerud says. “Maybe I don’t have to beat myself up for having these thoughts in the first place.”