Inclusion Criteria:

   1. Written informed consent is obtained.

   2. The patient is an outpatient, man or woman of any ethnic origin, 18-75 years of age
   (inclusive).

   3. Patient reports insomnia for at least six months, and insomnia causes the patient
   distress.

   4. The Investigator determines that the patient meets diagnostic criteria for Chronic
   Insomnia according to International Classification of Sleep Disorders (ICSD) criteria.

   5. Sleep diary based screening shows sleep onset latency >30 minutes, and /or wake after
   sleep onset >30 minutes per night at least 3 nights per week, with combined
   wake-time-in-bed _> 45 minutes.

   6. The patient is in good health as determined by a medical and psychiatric history, and
   physical examination.

   7. Women must be surgically sterile, 2 years post-menopausal, or if of child-bearing
   potential, using a medically accepted method of birth control, and agree to continued
   use of this method for the duration of the study.

   8. The patient is willing and able to comply with study restrictions and to attend
   regularly scheduled clinic visits as specified in this protocol.

Exclusion Criteria:

   1. Has any clinically significant, uncontrolled medical or psychiatric conditions.
   (treated or untreated)

   2. Has a probable diagnosis of a current sleep disorder other than Chronic Insomnia.

   3. Used any prescription drugs disallowed by the protocol or clinically significant use
   of over-the counter(OTC) drugs within 14 days before the screening visit.

   4. Has a history of alcohol, narcotic, or any other abuse as defined by the DSM-V.

   5. Has a clinically significant deviation from normal in the physical examination.

   6. Is a pregnant or lactating woman. (Any woman becoming pregnant during the study will
   be withdrawn from the study.)

   7. Has any disorder that may interfere with drug absorption, distribution, metabolism, or
   excretion (including gastrointestinal surgery and succinic semialdehyde dehydrogenase
   deficiency)

   8. Has a known clinically significant drug sensitivity to sodium oxybate or sedative
   hypnotics.