The aim of this Phase 1 treatment trial is to improve the quality of nocturnal sleep and decrease the need for daytime sleep by restoring a normal circadian pattern of melatonin levels in children with Smith-Magenis syndrome (SMS). We predict that the inverse pattern of release can be corrected by the combination of non-pharmacological suppression of daytime melatonin release and pharmacological replacement of nocturnal melatonin. Negative behaviors associated with accumulated sleep debt are expected to diminish as sleep quality improves.