3. Sleep: The Pittsburgh Sleep Quality Index (PSQI) was applied to evaluate sleep timing, sleep onset latency, sleep duration, sleep difficulties, and sleep quality. The PSQI is a self-reporting questionnaire that assesses sleep quality over a 1-month time interval. The PSQI consists of 19 individual items comprising seven components that produce one global score. The PSQI is a standardized sleep questionnaire for clinicians and researchers to use with ease and for multiple populations, used in many research and clinical settings to diagnose sleep disorders (Buyess et al., 1989; Shocat et al., 2007). The Karolinska Sleepiness Scale (KSS) was used to assess sleepiness and tiredness. It is a nine-point Likert scale; all of the numbers have valid point values, but only the odd numbers have descriptions: 1 = "extremely alert," 3 = "alert," 5 = "neither alert nor sleepy," 7 = "sleepy," and 9 = "extremely sleepy" (Akerstedt and Gillberg, 1990; Gillberg et al., 1994)