Patient description: A 57-year old farmer was diagnosed with Parkinson's disease a year ago. He experiences slowness of movement and tremors. His past medical history is significant for hypertension and hypercholesterolemia. He lives with his wife. They have three children. He used to be active with planting and taking care of their farm animals before his diagnosis. The patient complains of shaking and slow movement. He had difficulty entering through a door, as he was frozen and needed guidance to step in. His handwriting is getting smaller. He is on Levodopa and Trihexyphenidyl. He stated his medications help with shaking and slow movement. But he still has difficulty initiating movements, stiffness and slowness in general. He is an alert and cooperative man who doesn't have any signs of dementia. He doesn't smoke or use any illicit drugs.

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Transient Insomnia Signed written consent form Experienced at least 1 prior episode of transient insomnia meeting all of the following 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 5 hours in bed each night, with bed time varying no more than 2 hours over a week. Potential participants will be required to complete a paper diary for a minimum of 7 days during the screening period, with at least 5 entries completed over the 7 days 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 Female subjects of childbearing potential must be using an acceptable method of contraception during the study and for the 30 days following the last dose of study drug, and must have a negative urine pregnancy test at every study visit. Female subjects of non-childbearing potential are not required to use contraception if they have been surgically sterilized or are post-menopausal as defined by the cessation of menses for a period of at least 2 years before screening Male subjects must use an acceptable method of contraception during the study and for the 30 days following the last dose of study drug Willing and able to be confined to the study center for 1 night in each of 4 treatment periods, as required by the protocol Refrains from the use of alcohol within 24 hours of check-in for each of 4 treatment periods involving an overnight stay at the study center  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 Clinically significant abnormal finding on physical examination, as determined by the investigator Lifetime history of seizure disorder (other than childhood febrile seizures) or serious head injury History of chronic insomnia or other sleep disorders, such as sleep apnea, narcolepsy, parasomnia, restless leg syndrome, or circadian rhythm disorder Air travel across more than 2 time zones, an expected change in sleep schedule, or involvement in night work or shift work within 1 month before screening or during the study period Reports a recent history of napping of more than once per week