Individuals with seasonal affective disorder (SAD) — a winter depression linked to loss of motivation and interest in daily activities — tend to have misconceptions about their own sleeping habits, similar to those of insomniacs, according to researchers at the University of Pittsburgh.
The findings may lead to new treatments for seasonal affective disorder that are similar to treatments for insomnia.
The researchers wanted to know why, according to a previously published sleep study by the University of California, Berkeley, individuals with seasonal affective disorder incorrectly reported that they slept four more hours a night in the winter.
“We wondered if this misreporting was a result of depression symptoms like fatigue and low motivation, prompting people to spend more time in bed,” said Kathryn Roecklein, Ph.D., primary investigator and assistant professor in the Department of Psychology.
“And people with seasonal affective disorder have depression approximately five months a year, most years. This puts a significant strain on a person’s work life and home life.”
The research team interviewed 147 adults (ages 18 to 65) living in the Pittsburgh metropolitan area during the winters of 2011/ 2012. Data was collected through self-reported questionnaires and structured clinical interviews in which participants were asked questions such as the following:
In the past month, have you been sleeping more than usual?
How many hours, on average, have you been sleeping in the past month?
How does that compare to your normal sleep duration during the summer?
In order to understand participants’ ideas about sleep, researchers asked the participants to respond to statements such as “I need at least 8 hours of sleep to function the next day” and “Insomnia is dangerous for health” on a scale from 0 to 7, where 7 means “strongly agree” and 0 means “disagree completely.”
The findings showed that the misconceptions about sleep held by SAD sufferers were similar to the “unhelpful beliefs” or personal misconceptions about sleep that insomniacs often report.
Due to depression, individuals with SAD, like those with insomnia, may spend more time in bed, but not actually sleeping — leading to misconceptions about how much they sleep.
These misconceptions, said Roecklein, play a significant role in sleep cognition for those with SAD.
“We predict that about 750,000 people in the Pittsburgh metro area suffer from seasonal affective disorder, making this an important issue for our community and the economic strength and vitality of our city,” said Roecklein.
“If we can properly treat this disorder, we can significantly lower the number of sufferers in our city.”
The researchers believe that psychotherapy could help manage these unhelpful beliefs about sleep and could lead to improved treatments for seasonal affective disorder.
Roecklin noted that one of the most effective insomnia treatments is cognitive behavioral therapy for insomnia (known as CBT-I), which is designed to help people take control of their thinking as a way to improve their sleep habits as well as their mood, behavior, and emotions.