Adult Polysomnography Primary Insomnia Cross Over Study (0928-049)(TERMINATED)

Inclusion Criteria: * Diagnosis of Primary Insomnia * Patient is willing to stay overnight at a sleep laboratory for a total of 7 nights * Patient is willing to avoid alcohol on PSG visits * Patient will avoid napping during the course of the study * Patient's bedtime is between 9pm and 1am Exclusion Criteria: * History of substance abuse, bipolar disorder or psychotic disorder * Difficulty sleeping due to other medical condition * History of narcolepsy, circadian rhythm sleep disorder, parasomnia, sleep apnea, periodic limb movements or restless legs syndrome * History of neoplastic malignancy within the last 5 years * Positive alcohol breath test during the screening visits