3 month history of Primary Insomnia (DSM-IV criteria)

Self report sleep criteria for at least 3 nights per week in past month;

sWASO (subjective wake after sleep onset) equal or greater than 60 mins

sLSO (subjective latency to sleep onset) equal or greater than 45 minutes

TST less than or equal to 6.5 hrs

Maintain normal daytime-awake, nighttime-sleep schedule

PSG sleep criteria of mean WASO equal or greater than 60 mins calculated on 2 PSG screening nights

TST between 3 to 7 hrs on 2 PSG screening nights

Mean LPS (latency to persistent sleep) equal or greater than 20 mins calculated on 2 PSG screening nights

A Dose-ranging, Multicenter Polysomnography Trial of PD 0200390 in Adults With Primary Insomnia