“…Independently of the distinct circadian peak coincident with the beginning of the organism's activity cycle, another low-amplitude circadian peak may be apparent in some individuals, following the midday meal and located in the early afternooon (Quigley and Yen, 1982;Follenius et al, 1982). Cortisol is therefore considered as a strong oscillator, and thus as a marker of the circadian rhythmicity in man (Touitou et al, 1982(Touitou et al, , 1983. Indeed, except for endocrine diseases, such as Cushing's syndrome, in which the circadian rhythm of cortisol is dramatically disrupted, and psychiatric diseases, such as depression, in which cortisol rhythm is present, although some of its parameters, e.g.…”