Why does my brain race at night even when I'm tired?

This is extremely common in ADHD. During the day, structure and stimulation help regulate the brain. At night, when external demands drop, internal thoughts often surge. Mental restlessness, replaying conversations, and racing ideas can appear just as the body is exhausted. This is not a failure to relax. It reflects difficulty down regulating without structure. Clinicians often address this with sleep routines, reducing stimulation earlier in the evening, and sometimes medication timing adjustments.