Metabolomics of Insomnia-Related Hyperarousal

Participants with insomnia met the following Research Diagnostic Criteria for primary insomnia: subjective complaint of difficulty initiating or maintaining sleep, waking up too early or nonrestorative sleep, daytime consequences as a result of the poor sleep, duration of at least 1 month, sleep disturbance is not secondary to a medical or psychiatric condition based or the effects of a substance, as determined by clinical history. In order to exclude individuals with mild insomnia, insomnia had to occur on 3 or more nights per week for three months or longer. A 30-minute criterion was used such that subjects had to report taking 30 minutes or longer to fall asleep and/or spend 30 minutes awake during the night.

To be considered a good sleeper, participants had to report that they did not have difficulty falling asleep or staying asleep. A 15-minute criterion was used such that subjects had to report taking 15 minutes or less to fall asleep and spend 15 minutes or less awake during the night.