Effect of LDX on daytime dysfunction (component 7) PSQI scores. Mean PSQI component 7 score (daytime dysfunction component) decreased significantly after treatment with LDX. Numbers within bars indicate numbers of subjects. (SD = standard deviation; SE = standard error; LS = least squares; PSQI = Pittsburgh Sleep Quality Index; LDX = lisdexamfetamine dimesylate). P-values for "all LDX doses" calculated by analysis of covariance with baseline score as covariate. P-values for individual LDX dose groups calculated by Dunnett's test for multiple mean comparisons with least-squares (LS) adjustment. * P < .01 vs placebo.