PER3 and Anxiety: In order to test the hypothesis that PER3 genotype and sleep duration would have a combined impact on mood, univariate 2X2 ANOVA’s were used to compare the effect of PER3 genotype (4 and 5 repeat allele carriers) and sleep duration (≤6 hours of sleep, >6 hours of sleep) on the four independent measures of mood: the CES-D, state anxiety (STAI), trait anxiety (STAI), and the POMS total mood disturbance score.