Obesity & Depression Linked to Daytime Sleepiness

Amy Taylor May 11, 2015

Wondering why you still feel sleepy during the day even though you are getting enough sleep at night? According to a new study, other than insomnia, depression and obesity are common underlying causes for daytime sleepiness (EDS). Such findings may help experts develop a more personalised treatment plan for those experiencing regular daytime drowsiness.

EDS is a condition that is characterised by excessive drowsiness during the day, which may be accompanied by irresistible sleep attacks. People with EDS may feel overly tired despite not being engaged into physically or mentally exhausting tasks. EDS can affect a person’s life by making him or her prone to errors, productivity loss, and absenteeism. It also increases the risk of accident.

“In the medical field, there is a widespread belief that if you feel sleepy during the day, it’s because you didn’t get enough sleep,” said Julio Fernandez-Mendoza, assistant professor of psychiatry at the Sleep Research and Treatment Centre at Pennsylvania State College of Medicine.

Their research suggests that there could be more serious causes for daytime sleepiness.

“We need to start abandoning this idea. If we continue to believe that the only cause of excessive daytime sleepiness is people sleeping too little, we are missing the vast majority of the population.”

“The main causes of a sleepy society are an obese society, a depressed society and, to some extent, people who have a physiological disorder. By looking at our patients more closely, we can start personalizing sleep medicine,” he added.

Previous studies have shown a link between obesity, depression and sleep apnoea, and EDS. However, this is the first study to use physiologic sleep data to identify its cause and investigate the mechanisms behind it.

At the start of the study, researchers measured the EDS of participants based on self-reports, and again an average of 7.5 years later. Participants completed a comprehensive sleep history and physical examination and were evaluated for one night in a sleep laboratory.

Researchers also looked at any sleep, physical and mental health problems and substance use and determined whether participants were being treated for physical and mental health conditions.

“Obesity and weight gain predicted who was going to have daytime sleepiness,” said Fernandez-Mendoza. “Moreover, weight loss predicted who was going to stop experiencing daytime sleepiness, reinforcing the causal relationship.” says Fernandez-Mendoza.

The research team notes that people with depression had high incidence of EDS. Physiologic sleep disturbances, including taking longer to fall asleep and waking up in the middle of the night, explained their daytime drowsiness.

“People with depression typically ruminate, they have difficulty shutting their minds off and they are more likely to have elevated stress hormones,” explains Fernandez-Mendoza.

The new findings, published in journal Sleep, may lead to the development of more personalised treatments for EDS patients.

Source of this article: Obesity, Depression Linked to Daytime Sleepiness