憂鬱星期一？由不同週末補眠策略探討補眠時數與社交時差，對於週間睡眠不足之影響

The Monday Blues? The Impacts of Catch-up Sleep Duration and Social Jet Lag on Insufficient Weekday Sleep with Different Weekend Sleep Strategies

週末補眠習慣一般是為了因應週間睡眠不足的情況，但先前研究較為關注補眠的效果，卻忽略了當週間週末睡眠時數改變，醒睡時間也會有所差異，可能造成「社交時差」產生並伴隨負面影響。因此，本研究以實驗法檢驗週末補眠的補償作用及社交時差的負向影響，最終納入69 名研究參與者，隨機區分為「週末晚睡晚起不補眠組（G1：n = 20）」、「週末晚睡晚起補眠組（G2：n = 24）」及「週末晚起補眠組（G3：n = 25）」， 三組皆進行兩週的實驗，基礎期時週間週末的作息相同，限制總躺床時數在7 小時內，結束後的週一早上以史丹福嗜睡量表量測主觀嗜睡度，並以盤斯心情量表量測情緒，再以心理動作警覺作業及連續注意力表現測驗來量測認知表現；實驗期與基礎期的差別在於週末會依不同組別調整作息。結果發現有補眠的兩組（G2、G3）在實驗期週末的入睡後清醒時間皆顯著高於基礎期；而週末晚起補眠（G3）組在實驗期結束後的週一早上，其疲倦分數及盤斯心情量表總分低於基礎期，與另外兩組之趨勢相反。本研究結果顯示週末補眠可能無法達到預期的補償作用，週末補眠越多，可能反映的是週間睡眠不足越嚴重，同時還會使社交時差增加，造成負向影響，而週末晚起補眠可能是相對較佳之策略。

Weekend catch-up sleep (CUS) is a strategy commonly used to cope with insufficient sleep during weekdays. Previous studies focused more on the usefulness of CUS in compensating for the sleep loss on weekday nights, but might have overlooked its possible negative influence due to “social jet lag (SJL)” resulting from the changes in the sleep-wake schedule. Thus, this study aimed to fill this gap by exploring the effects of different weekend sleep patterns, with different degrees of CUS and SJL, on subsequent sleep and daytime functioning with an experimental design. The study included 69 young healthy adults as participants. They were randomly assigned to three groups: a “delayed weekend sleep schedule” group (G1: n = 20), a “delayed weekend sleep schedule + CUS” group (G2: n = 24), and a “delayed weekend rising schedule + CUS” group (G3: n = 25). All participants had to go through a two-week study period: a baseline week and an experimental week. During the baseline week, participants had to restrict their time in bed (TIB) to 7 hours each night; during the experimental week, they were required to follow a regular sleep schedule with a restricted TIB of 7 hours on weekday nights, and to follow one of three experimental sleep patterns on weekends. The weekend sleep pattern of G1 consists of no CUS and 2 hours of SJL; G2 was composed of 2 hours of CUS and 2 hours of SJL; G3 involved 2 hours of CUS and 1 hour of SJL. Upon awakening from the last nights of the baseline and experimental periods, each participant rated their subjective sleepiness on the Stanford Sleepiness Scale (SSS) and emotion on the Profile of Mood State (POMS), and then came to the laboratory to complete the Psychomotor Vigilance Task (PVT) and the Continuous Performance Test (CPT) on the following Monday morning. Those groups with CUS (G2 and G3) showed higher wake after sleep onset (WASO) on weekend nights in the experiment period than the baseline. G3, compared to the other two groups, showed a trend of decreased negative emotion after the experimental night. However, G1 and G2 showed increased negative emotion compared to their baseline. The findings suggest that CUS might not be a good coping strategy to compensate for insufficient sleep on weekdays. More CUS might lead to larger SJL, which was found to be related to elevated levels of negative mood. The possible compensatory effect of CUS might be cancelled out by the negative effect of SJL.