Derailment (thought disorder)

Derailment (thought disorder) is when someone's thoughts jump from one idea to another in an unusual way. It's like when a little kid is telling a story and their thoughts go all over the place. It makes it hard for them to finish what they're saying. People with derailment might have trouble with their memory or understanding, or they might start talking about something completely different than what they were talking about before. It can feel like they're talking in circles and make it hard to follow.