Study of Eszopiclone Compared to Placebo on Daytime Function in Subjects With Insomnia Related to Rheumatoid Arthritis

Inclusion Criteria * Subject must understand the purpose of the study and be willing to adhere to the study schedule and procedures described in this protocol. * Subject must be 25-64 years of age (inclusive) on the day of signing consent. * Subject must be diagnosed with rheumatoid arthritis as defined by the American College of Rheumatology. * Subject must be on stable regimen for treatment of rheumatoid arthritis for a minimum of 90 days prior to study start. * Subject must report a wake time after sleep onset (WASO) of greater than or equal to 45 minutes and less than or equal to 6.5 hours of total sleep time at least three times a week over the previous month and symptoms of insomnia must post date onset of rheumatoid arthritis. * Subject physical exam must show no clinically significant abnormal findings (other than those related to rheumatoid arthritis) at screening. * Subject must have no clinically significant abnormal laboratory findings at screening (other than those related to rheumatoid arthritis). * Subject must have no clinically significant ECG abnormalities at screening. Exclusion Criteria * Subject has diagnosis of fibromyalgia, or juvenile rheumatoid arthritis. * Subject has history of circadian rhythm disorder, or travels across \>3 time zones on a regular basis. * Female subject is pregnant, lactating or within 6-months post partum. * Subject has a history of drug or alcohol abuse or dependence in the past 2 years or positive urine drug test at screening. * Subject has clinically significant unstable medical abnormality or unstable chronic disease (other than insomnia and rheumatoid arthritis) including severe cardiac, renal, or hepatic or respiratory disease, seizure disorder. * Subject has participated in any investigational drug study within 30 days prior to screening or plans to participate in any investigational drug study during participation in this study. * Subject has a history of malignancy within 5 years, or current malignancy, except for non-melanoma skin cancer. * Subject has a current primary psychiatric diagnosis of any of the following disorders: dementia, delirium, schizophrenia, psychosis, other psychotic disorders, dysthymic disorder; major depressive disorder, bipolar disorders; cyclothymic disorder, other mood disorders, primary anxiety disorders, primary panic disorders, or any nocturnal panic disorder. * Subject has any of the following Personality Disorders diagnoses: schizotypal, schizoid, borderline personality disorder; or any other personality disorder that would compromise the investigator's ability to evaluate the safety and efficacy of the study medication. * Subject has difficulties in sleep initiation or maintenance associated with known medical diagnosis \[e.g. sleep apnea\]; diagnosed and untreated restless leg syndrome (RLS) or periodic leg movement syndrome (PLMS). * Subject has used any drugs known or suspected to affect hepatic or renal clearance capacity within a period of 30 days prior to screening. * Subject reports consumption of more than two alcoholic beverages daily, 14 or more alcoholic beverages weekly, or five or more alcoholic beverages on any given day. * Subject is a rotating or third/night shift worker. * Subject is a staff member or relative of a staff member.