Fifty chronic insomniacs participated in a one-month study conducted at an institute for sleep disorders  Half were given a dose of a new drug and the other half were given a placebo every night before going to bed at the institute  Approximately 80 percent of the participants in each group reported significant relief from insomnia during the first two weeks of the study
But in each group, approximately 90 percent of those who had reported relief claimed that their insomnia had returned during the third week of the study
Some insomniacs cannot reliably determine how much sleep they have had or how well they have slept.