Subjective mood is influenced by sleep-related and circadian processes in a forced desynchrony protocol with severe sleep restriction

Aims: Studies show subjective mood declines when sleep is severely restricted to 4-5hper night. In addition, mood follows a circadian rhythm such that subjective mood is lowest around the circadian nadir. These findings are important for shiftworkers who often report severe sleep restriction and are subject to circadian disruption. The current study aims to examine the effect of prior wake and circadian phase on subjective mood when sleep is severely restricted to the equivalent of 4h of sleep opportunity per 24-h day.