People with seasonal affective disorder (SAD) have similar types of misperceptions about sleep as people with insomnia, according to a small recent study.
Researchers from the University of Pittsburgh found that people with SAD -- which is a kind of depression that occurs in the late fall, winter and early spring -- tend to have incorrect perceptions of their own sleep habits, such as how much time they actually spend sleeping at night. Characteristic symptoms of SAD include depression, oversleeping, anxiety, problems concentrating and feelings of hopelessness, according to the Mayo Clinic. While the cause is not completely known, it likely has to do with a person's individual circadian rhythm, drops in the brain chemical seratonin, and disruptions in melatonin levels.
For the study, published in the Journal of Affective Disorders, researchers had 147 adults between ages 18 and 65 who live in Pittsburgh answer questionnaires about their sleep habits. Participants were asked to rank on a scale of 0 to 7 how much they need "at least eight hours of sleep to function the next day" or if they agreed with the statement, "Insomnia is dangerous for health."
Researchers found similarities between insomniacs and people with SAD, with regard to their "unusual beliefs" about sleep. For example, just like people with insomnia, people with SAD may spend more time in their beds, even if they're not actually sleeping while in their beds -- leading them to think that they are getting more rest than they really are.
These sleep perception similarities between insomnia and SAD could help lead to better treatments for people with SAD, researchers said. Right now, cognitive behavioral therapy is considered the best treatment for insomnia.