Effects of worry postponement on daily worry and sleep: a randomised controlled trial

Previous studies have shown that perseverative, worrisome thoughts are prospectively related to poor sleep outcomes and that worry postponement interventions may be effective in reducing worry. However, their effectiveness for improving sleep outcomes is unknown and they have not been tested over a period longer than 7 days. The current study investigated the effects of a worry postponement intervention, alongside a worry postponement + planning intervention (augmented condition) against active and non-active control conditions on daily worry and sleep outcomes.

A four-armed (online) randomised controlled trial (RCT) was conducted using an interval-contingent design, where self-report measures of worry each night (duration & frequency for that day) and sleep (sleep onset latency; number of awakenings, sleep quality) each morning (for the previous night) were collected within 186 participants (M^age = 30.34; SD = 7.89) across 14 days.

Participants in the augmented arm reported significantly lower worry duration (by ∼15 min), relative to the standard worry postponement arm alone. However, the intervention arms did not produce significant improvements in any of the sleep outcomes, relative to the control groups.

Creating specific 'if-then' plans for when and how to engage in a worry postponement can produce favourable outcomes for worry reduction; however, future studies are needed to unpick how to best translate these effects into positive outcomes for sleep.