What specific sleep deficit was noted in participants taking longer to fall asleep during full moon nights?

Subjects spent about five minutes longer falling asleep

Scientific investigation has provided some support for anecdotal reports regarding sleep disruption around the full moon phase. A particular study revealed measurable changes in sleep architecture even when participants were unaware of the current lunar phase. The findings indicated that during the nights surrounding the full moon, subjects experienced difficulties initiating sleep, taking approximately five minutes longer to fall asleep than during other times. Furthermore, this period was associated with sleeping 20 minutes less overall and experiencing a notable decrease in the amount of deep sleep achieved, suggesting a real, though perhaps mild, physiological response to the increased ambient light present.