Chronic insomnia affects approximately 8-9% of the population. The prevalence of this disorder rises dramatically across the lifespan, especially so in women. When it is chronic, insomnia is associated with increased fatigue, cognitive impairment, mood disturbance, physical complaints, diminished quality of life and increased health care consumption. There is also more limited evidence (based on epidemiologic studies or experimental studies in healthy subjects) that insomnia and/or sleep loss may be a risk factor for hypertension and/or cardiovascular disease and increased mortality.

Despite its prevalence and consequences, the pathophysiology of insomnia and, specifically, the pathway by which morbidity risk is conferred, has been relatively unstudied. With respect to medical illness in particular, insomnia may confer risk in several ways, including: 1) an inherent compromise in the restorative/conservative function of sleep, 2) the deleterious effects of "hyperarousal" and/or HPA axis abnormalities on end organ integrity and function, and/or 3) diminished immunocompetence. This study focuses on the last of these possibilities, the relationship between immune function and sleep.

The study compares immune response to a vaccine challenge in two groups: good sleepers and patients with chronic insomnia. The primary study hypothesis is that the insomnia group will have a decreased rate of adaptive immune response to the vaccine challenge than that of the good sleeper group.

Inclusion Criteria:

Their sleep schedule will include a typical bedtime of between 9:00 p.m. and 12:00 a.m. to minimize circadian rhythm influences on the diagnoses of Primary Insomnia (PI).

PIs will also meet the sleep disturbance criteria of the Pittsburgh Sleep Quality Index(PSQI) > 5 and the Insomnia Severity Index (ISI)> 15 and one of the following minimal characteristics both at intake and as an average profile from the two weeks of baseline diaries: > 30 min. sleep-onset latency (SL), > 30 min. of wake after sleep-onset (WASO), Early Morning Awakening >30 min. prior to the desired wake up time, or any two of the above complaints (Mixed Insomnia); Total Sleep Time (TST) < 6 hours [unless the Sleep Efficiency is < 80%] and the problem frequency must be > 3 nights/week; problem duration > 6 months.

Good Sleeper participants will report that they obtain enough sleep and that their sleep is restorative with average SL and WASO < 15 minutes, TST > 6 hours ESS < 5 on the ESS, < 5 on the PSQI, and < 7 on the ISI.

Exclusion Criteria for All Subjects

• any conditions contraindicated by the vaccine manufacturer or any history of allergic reactions to vaccines
• Undergoing and/or taking immunosuppressive therapies
• Sero-positive for Hep B antibodies
• Inadequate language comprehension
• Menopause, peri-menopause or premenstrual syndrome
• Pregnancy
• Unstable medical or psychiatric illness
• History of head injury with a sustained loss of consciousness
• Evidence of active illicit substance use or fitting criteria for alcohol abuse or dependence
• Use of medications thought to alter sleep such as stimulants, sedating antidepressants, and hypnotics
• Symptoms suggestive of sleep disorders other than Insomnia
• Polysomnographic data indicating sleep disorders other than Insomnia

Community Sample

Sample size limited by much higher than expected number of otherwise eligible participants having alrady been exposed to Hep B vaccine or virus.