Why Does Rumination Get Worse at Night?

The days are fine. She manages. She has work to do, people to talk to, tasks that occupy her attention. She is not happy exactly, but she is functional. The moment she lies down, everything she managed to set aside returns – at full intensity, in the dark, with nothing else to compete for her attention.

Night rumination is not a different type of thinking from daytime rumination. It is the same content, with different conditions. During the day, cognitive demands – tasks, conversations, decisions – compete with the ruminating thoughts. At night, nothing competes. The thoughts have the field entirely to themselves.

There is also something about the transition to sleep that seems to trigger the content. The mind, moving from active to passive, loses its usual ability to set things aside through distraction. The material that was being held at bay surfaces as the distracting mechanisms fall away.

The more she tries to stop the thoughts at night, the louder they become. This is a known pattern: thought suppression tends to increase the frequency and intensity of the suppressed material. The effort to not think about something keeps the thing in mind.