An Investigational Study to Assess Efficacy and Pattern of Use of SM-1 in Subjects With a History of Transient Insomnia

Inclusion Criteria: * Experienced at least 1 prior episode of transient insomnia meeting all of the following criteria: difficulty falling asleep or staying asleep; next day impairment or distress associated with the disturbed sleep; frequency of 1 to 7 nights per week; duration of less than 1 month or more than 1 month of intermittent episodes. * Routinely spends 6.5 - 9.5 hours in bed each night, with bed time varying no more than 2 hours over a week. * Body Mass Index (BMI) between 19 and 32 kg/m2. * Good general health, as determined by a thorough medical, sleep and psychiatric history review, brief physical examination including vital sign measurements, and an assessment of screening laboratory test results. * Agrees, for the duration of the study, to take only study drug to address difficulty falling asleep or staying asleep, and to not drink alcohol within 2 hours of expected bedtime. Exclusion Criteria: * Females who are pregnant, breast-feeding, or planning a pregnancy during the study period. * Clinically significant medical disorder or currently unstable medical condition that, in the opinion of the investigator, would confound the results of the study. * Abnormal laboratory value at screening, judged clinically significant by the investigator. * History or current evidence of severe hepatic (liver) impairment. * Clinically significant psychiatric illness, or the history or presence of a major psychiatric illness in the past year. * Has a significant risk (in th…