Insomnia may be associated with a wide variety of prescription drugs and other conditions, such as Parkinson's disease, Alzheimer's disease, coronary artery disease, cancer, dementia, breathing difficulties (e.g., sleep apnea), or chronic conditions such as rheumatism (Graci G 2005; Power JD et al 2005).Hoping to better understand the connection between insomnia and diseases, researchers have cond