The effect of anticipatory stress and openness and engagement on subsequently perceived sleep quality - an Experience Sampling Method Study

High stress levels can influence sleep quality negatively. If this also applies to anticipatory stress is poorly documented, however. Across insomnia severity levels, this study examined participants' evening levels of (a) anticipatory stress and (b) their skills hypothesized to downregulate the impact of stress, namely openness to internal experiences and continuous engagement in meaningful activities (openness and engagement) and their association with the quality of the subsequent night's sleep. The moderating role of insomnia severity was also tested. We used a quasi‐experimental longitudinal design with Experience Sampling Method using smartphones over the course of 1 week (3,976 assessments; 93.2% of prompted queries). Participants recorded their sleep quality, anticipatory stress, and openness and engagement within their daily context. Participants included in the study were diagnosed with major depressive disorder (n = 118), social phobia (n = 47) or belonged to the control group (n = 119). Both anticipatory stress and openness and engagement predicted subsequent sleep quality. Diagnostic group was associated with overall sleep quality, but did not interact with the predictors. These findings were invariant across levels of self‐reported insomnia severity. Furthermore, openness and engagement and anticipatory stress did not interact in their effect on sleep quality. The results suggest that both stress reduction and increased openness and engagement are associated with improved subjective sleep quality on a day to day basis, regardless of insomnia severity. Targeting these variables may help improve sleep quality. Future research should disentangle the effects of openness and engagement on anticipatory stress.