Daytime intrusive thoughts and subjective insomnia symptoms

• First study of association between insomnia symptoms and daytime intrusive thoughts.
• Insomnia symptoms predicted subjective and behavioural measures of thought control.
• Insomnia symptoms were uniquely associated with negative thought intrusions.
• We highlight thought control/intrusions as a therapeutic target in early insomnia.

Insomnia is increasingly recognised as a 24 h complaint that is associated with an increased risk of mood and anxiety disorders. However, the effects of insomnia symptoms on maladaptive daytime patterns of thinking are poorly understood. We examined the relationship between subjective insomnia symptoms, attentional control and negative thought intrusions during daytime in a large sample of undergraduates experiencing poor sleep. A total of 109 participants completed self-report measures of sleep quality, current sleepiness, anxiety and attentional control. A behavioural measure of intrusive thought required participants to control their attention during two focus periods separated by a 5 min period of self-referential worry. Thought intrusions were sampled throughout the pre- and post-worry periods. Perceived insomnia severity was associated with the reduced ability to focus attention and uniquely associated with increased negative thought intrusions in the pre-worry period. These results support suggestions that acute episodes of poor sleep can dysregulate key networks involved in attentional control and emotion regulation, and that promote negative cognitive activity.