Table 1: Prevalence of nightmares and overall sleep duration separated for reported nightmare frequencies.

Prevalence Sleep Duration
Nightmares Percent M SD
Never 38.9% 453.23 66.96
Less than once a week 36.9% 462.08 67.90
Once/twice a week (weekly nightmares) 18.5% 454.77 77.34
3 times or more per week (frequent nightmares) 5.8% 450.05 90.53