In a possible contradiction to common belief that a person's body mass index, immune responses and stressful life events are factors that may cause narcolepsy, a comprehensive review published in the January 1st issue of the journal SLEEP finds that, as with other diseases characterized by selective cell loss, narcolepsy may be caused by environmental exposures before the age of onset in genetically susceptible individuals. Continue reading the full article in "Sleep", January 1, 2007.