“…Previous studies of the effects of wake therapy on melatonin amplitude measures showed primarily no effect (Jimerson et al, 1977; Touitou et al, 1992; von Treuer et al, 1996; Leproult et al, 1997; Goichot et al, 1998; Kudo et al, 1999; Redwine et al, 2000), although some observed an increase (Akerstedt et al, 1979; Salin-Pascual et al, 1988; Goh et al, 2001), and some a decrease (Rao et al, 1996; Shilo et al, 1999; Cajochen et al, 2003). These disparate results may be due to different methodologies employed, including the timing and frequency of the melatonin measurements in relation to sleep deprivation, light and activity conditions, the use of plasma versus urinary or salivary measures, the duration and timing of the change in sleep phase or sleep deprivation, and the method used to analyze melatonin amplitude or phase.…”