Efficacy of Ramelteon in Adults With Chronic Insomnia

Inclusion Criteria * Females of childbearing potential who are sexually active must agree to use adequate contraception, and can neither be pregnant nor lactating from Screening throughout the duration of the study. * Has had primary chronic insomnia as defined by Diagnostic and Statistical Manual of Mental Disorders, 4th Edition Revised for at least 3 months. * Reports a history of subjective sleep latency greater than or equal to 60 min and a subjective total sleep time less than 6.5 hours. * Habitual bedtime is between 10:00 PM and 1:00 AM. * Willing to have a fixed bedtime and agrees to go to bed within plus or minus 30 minutes of the habitual bedtime during the entire study. * Consistent access to a touch tone phone and are willing to complete telephone questionnaires twice daily during participation in the study. * Willing to remain in bed for at least 6.5 hours each night during the entire study. * Used pharmacological assistance to sleep 0-4 times per week in the last 3 months. * Must complete the morning questionnaire on at least 4 of the first 7 mornings after Screening Visit 1. * On at least 3 of the first 5 nights of single-blind placebo treatment, the subject must have a subjective sleep latency of greater than or equal to 45 minutes. * On at least 3 of the first 5 nights of single-blind placebo treatment, the subject must have a subjective total sleep time of less than 6.5 hours. Exclusion Criteria * Known hypersensitivity to ramelteon or related compounds, including melatonin, and 5-hydroxytryptophan. * Participated in any other investigational study and/or took any investigational drug within 30 days prior to the first dose of single-blind study medication. * Sleep schedule changes required by employment (eg, shift worker) within 3 months prior to the first night of single-blind study medication. * Has flown across greater than 3 time zones within 7 days prior to screening, or will travel across 2 or more time zones during the course of the study. * Participated in a weight loss program or has substantially altered exercise routine within 30 days prior to the first night of singleblind study medication. * Ever had a history of seizures, sleep apnea, and/or chronic obstructive pulmonary disease. * History of psychiatric disorder within the past 6 months. * History of fibromyalgia. * History of drug addiction or drug abuse within the past 12 months. * History of alcohol abuse within the past 12 months, as defined in Diagnostic and Statistical Manual of Mental Disorders, 4th Edition Revised and/or regularly consumes more than 2 alcoholic drinks per day. * Current significant hepatic, renal, endocrine, cardiovascular, gastrointestinal, pulmonary, hematologic, or metabolic disease, unless currently controlled and stable with protocol-allowed medication, within 30 days prior to the first night of single-blind study medication. * Uses tobacco products or any other products that may interfere with the sleep wake cycle during nightly awakenings. * Any clinically important abnormal finding as determined by a medical history, physical examination, electrocardiogram, or clinical laboratory tests, as determined by the investigator. * Positive hepatitis panel. * Any additional condition(s) that in the Investigator's opinion would: * affect sleep/wake function * prohibit the subject from completing the study * indicate that continuation in the study would not be in the best interests of the subject. * Is required to take or continues taking any disallowed medication, prescription medication, herbal treatment or over-the counter medication, including: * Anxiolytics * Central nervous system active drugs * Hypnotics * Narcotic analgesics * Antidepressants * Beta blockers * Anticonvulsants * St. John's Wort * Sedating H1 antihistamines * Kava-kava * Systemic steroids * Ginkgo-biloba * Respiratory stimulants * Over-the-counter and prescriptions stimulants * Decongestants * Over-the-counter and prescription diet aids * Antipsychotics * Melatonin and all other drugs or supplements known to affect sleep/wake