Insomnia: Risk Factor for Neurodegenerative Diseases

Insomnia can be defined as difficulty falling asleep or maintaining sleep, waking up earlier than expected, or having non-restorative sleep. It is one of the most common sleep disorders in the world. Insomnia is a common symptom of many neurodegenerative diseases but only recently has it been found that it is a risk factor for neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. We did a traditional review to analyze the relationship between insomnia and neurodegenerative diseases. We analyzed all the relevant articles on Pubmed and included studies done on humans over the last 10 years with full text available. After reviewing the available literature on Pubmed, we conclude that insomnia is an important risk factor for neurodegenerative diseases. In addition, insomnia and neurodegenerative disorders have a complex and bi-directional relationship. We think it requires further study to understand the sole contribution of insomnia to the development of various neurodegenerative diseases when different factors like mood problems, genetic factors, and environmental factors also contribute to the disease. It would also be advisable to use cognitive screening questionnaires in all sleep clinics in insomnia patients over 50 years of age to diagnose dementia early and to gather more sleep study data for prospective and retrospective research. The role of hypnotics in preventing neurodegenerative diseases through treating insomnia should also be assessed.