Longitudinal study on perfectionism and sleep disturbance

Aim. To examine if perfectionism predicts self-reported sleep disturbances over time. Methods. The HewittFlett Perfectionism Scale was used to assess self-oriented, socially-prescribed (SPP) and other-oriented perfectionism. Sleep disturbance was evaluated with two items: difficulty in falling asleep and waking up many times during the night. Out of 870 students who participated at baseline, 592 and 305 completed the same measures 1 year (T1) and 2 years later (T2), respectively. Results. Subjects who reported insomnia at baseline, T1 and T2 (persistent insomnia) had significantly higher scores of baseline SPP (T1 M = 51.5, SD = 15.8; T2 M = 55.0, SD = 19.0) than subjects reporting, in all stages of the study, never/rarely having had sleep problems (T1 M = 41.9, SD = 11.4; T2 M = 42.2, SD = 12.3, P<0.001 in both cases). Regression analyses showed that baseline SPP was the only significant positive predictor of difficulties in falling asleep at T1 and T2 (T1 partial R=0.187; T2 partial R=0.196, P<0.001) and of difficulties maintaining sleep (T1 partial R=0.116; T2 partial R=0.244, P<0.001). Conclusion. SPP was found to be the most reliable predictor of sleep disturbances over time, which constitutes a new important finding.