Symptom-focused rumination and sleep disturbance.

Rumination can prolong negative mood, disrupt sleep, and increase depression risk. Although there is evidence that poor sleepers ruminate, no studies have identified the ruminative content relevant for sleep disturbance. This study investigated (a) the association between rumination and sleep and (b) the ruminative content of poor sleepers. Results revealed that self-defined poor sleepers (n = 104) were more prone than self-defined good sleepers (n = 139) to ruminate and that the ruminative content was symptom focused (e.g., poor sleepers ruminated on causes of dysphoria, concentration, and fatigue symptoms). As dysphoria, reduced concentration, and fatigue are all commonly experienced daytime symptoms of insomnia, this preliminary finding of symptom-focused rumination should be further evaluated as a risk factor for further sleep disturbance in clinical samples as well as a possible link between insomnia and depression.